{"title":"EG4","description":"\u003cp\u003eEG4 hybrid inverters and WallMount battery systems — scalable home energy storage built around the FlexBOSS inverter platform and 16 kWh wall-mounted LiFePO4 batteries.\u003c\/p\u003e","products":[{"product_id":"eg4-flexboss18-wallmount-314ah-all-weather-battery-kit-16-48-kwh-home-ess","title":"EG4 FlexBOSS18 + WallMount 314Ah All-Weather Battery Kit | 16–48 kWh Home ESS","description":"\u003cp\u003eThis kit pairs the EG4 FlexBOSS18 hybrid inverter — up to 18 kW of PV input and 13 kW of continuous split-phase AC output per EG4 — with the EG4 WallMount 314Ah All-Weather battery, an IP67-rated 16 kWh unit built for indoor or outdoor mounting. Configure one to three batteries for 16, 32, or 48 kWh of storage, all communicating in closed-loop within a single-manufacturer system. OffGrid Horizon is a family-owned authorized EG4 dealer, and every kit ships with full manufacturer warranty support.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Is For\u003c\/h2\u003e\n\u003cp\u003eHomeowners who want one matched, single-brand energy storage system for backup power, solar self-consumption, or off-grid living — with batteries that can mount outdoors beside the inverter. If your loads are typical residential (well pump, refrigeration, HVAC in reasonable combinations), the FlexBOSS18's 13 kW output covers most homes; households with heavier simultaneous 240V loads should look at the FlexBOSS21 version of this kit.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eUp to 18 kW of PV input\u003c\/strong\u003e (600VDC max, up to 4 strings per EG4) with 13 kW continuous split-phase 120\/240V output\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e10 kW continuous output from battery alone\u003c\/strong\u003e per EG4 — the figure that matters at night and during outages\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIP67 all-weather batteries\u003c\/strong\u003e — 16 kWh per unit, wall- or floor-mounted, indoor or outdoor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClosed-loop communication\u003c\/strong\u003e between inverter and batteries over CAN\/RS485, with Auto-ID addressing as you add units\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e10,000-cycle battery rating\u003c\/strong\u003e at 80% depth of discharge per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrid-tied, backup, and off-grid operating modes\u003c\/strong\u003e with app-based remote monitoring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNEMA 4X inverter enclosure\u003c\/strong\u003e per EG4, suitable for outdoor installation alongside the batteries\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy EG4\u003c\/h2\u003e\n\u003cp\u003eEG4 Electronics is a Texas-based manufacturer that builds both halves of this system, publishes full spec sheets and test data, and backs the inverter and batteries with 10-year warranties. One engineering team, one support line, one communication protocol — no cross-brand compatibility guesswork.\u003c\/p\u003e\n\n\u003ch2\u003eWhat's In the Kit\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1 x EG4 FlexBOSS18 hybrid inverter\u003c\/strong\u003e — split-phase 120\/240V, UL3141 and UL1741 certified per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1, 2, or 3 x EG4 WallMount 314Ah All-Weather batteries\u003c\/strong\u003e (16 kWh each) — the listed configuration includes one battery; select your capacity from the product options\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eSolar panels, racking, and array wiring are site-specific and sold separately. The system also operates as battery backup without solar.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eInverter\u003c\/td\u003e\n\u003ctd\u003eEG4 FlexBOSS18 hybrid, split-phase 120\/240V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePV input\u003c\/td\u003e\n\u003ctd\u003eUp to 18 kW (STC), 600VDC max, up to 4 strings, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAC output\u003c\/td\u003e\n\u003ctd\u003e13 kW continuous (grid-tied with solar contribution); 10 kW from battery alone, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInverter certifications\u003c\/td\u003e\n\u003ctd\u003eUL3141; UL1741, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInverter enclosure\u003c\/td\u003e\n\u003ctd\u003eNEMA 4X, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery\u003c\/td\u003e\n\u003ctd\u003eEG4 WallMount 314Ah All-Weather, 51.2V, 16 kWh nominal per unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCapacity options\u003c\/td\u003e\n\u003ctd\u003e16 \/ 32 \/ 48 kWh (1, 2, or 3 batteries)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery output\u003c\/td\u003e\n\u003ctd\u003e200A max continuous discharge per unit, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery enclosure\u003c\/td\u003e\n\u003ctd\u003eIP67 — indoor or outdoor mounting\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery certifications\u003c\/td\u003e\n\u003ctd\u003eUL1973; UL9540A, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery cycle life\u003c\/td\u003e\n\u003ctd\u003e10,000 cycles at 80% DoD, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery dimensions \/ weight\u003c\/td\u003e\n\u003ctd\u003e34.6 x 21.7 x 9.3 in \/ 309 lb per unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication\u003c\/td\u003e\n\u003ctd\u003eClosed-loop CAN\/RS485; app-based remote monitoring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003eInverter 10 years; batteries 10 years or 10,000 cycles, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBase SKU\u003c\/td\u003e\n\u003ctd\u003eK0286\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eGrid-Tied, Backup, or Off-Grid\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eGrid-tied:\u003c\/strong\u003e the FlexBOSS18 manages solar production, battery charging, and export under UL1741 interconnection rules — your utility and AHJ govern export permissions. \u003cstrong\u003eBackup:\u003c\/strong\u003e when the grid drops, the system transfers to battery power; one battery (16 kWh) carries essential circuits overnight, while 32 or 48 kWh supports whole-home coverage or multi-day outages. \u003cstrong\u003eOff-grid:\u003c\/strong\u003e the same hardware runs fully off-grid, sized by your daily load and sun hours. For whole-home microgrid control — AC coupling, smart load management, and generator integration per EG4 — add the \u003ca href=\"\/products\/eg4-gridboss-200a-mid-microgrid-interconnection-device\"\u003eEG4 GridBoss 200A MID\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eInverter Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe batteries in this kit run closed-loop with the included \u003ca href=\"\/products\/eg4-flexboss18-hybrid-solar-inverter-18-kw-pv-13-kw-ac-split-phase-3-mppt\"\u003eEG4 FlexBOSS18 hybrid inverter\u003c\/a\u003e, so state-of-charge and charge parameters stay coordinated out of the box. Want more output headroom? The FlexBOSS21 version of this kit uses the same batteries. Individual \u003ca href=\"\/products\/eg4-wallmount-314ah-all-weather-battery-48v-16-kwh\"\u003eWallMount 314Ah All-Weather batteries\u003c\/a\u003e are available separately when you are ready to expand.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eInstallation must be performed by a licensed electrician — the inverter interconnects with your main panel and, in grid-tied modes, with the utility, and energy storage installations require local permits and inspection. Each battery weighs 309 lb and mounts to the wall or floor per EG4's manual; anchor wall-mounted units into structural framing and plan for lifting equipment. Follow EG4's installation manuals for clearances, torque values, and conductor sizing.\u003c\/p\u003e\n\n\u003ch2\u003eWarranty \u0026amp; Support\u003c\/h2\u003e\n\u003cp\u003ePer EG4, the FlexBOSS18 carries a 10-year warranty and each WallMount battery is covered for 10 years or 10,000 cycles, whichever comes first. Register your equipment with EG4 after purchase and keep your OffGrid Horizon invoice — as an authorized dealer, our records document your coverage. For warranty or configuration help, call us at (302) 496-3554.\u003c\/p\u003e\n\n\u003ch2\u003eShipping\u003c\/h2\u003e\n\u003cp\u003eKits ship by LTL freight on pallets within the United States, curbside with a liftgate. Count every piece against the packing list and inspect for damage before signing the delivery receipt — note any issues with the driver to preserve your freight claim.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eHow many batteries are included?\u003c\/h3\u003e\n\u003cp\u003eThe base configuration includes one 16 kWh battery. Select the 2-battery (32 kWh) or 3-battery (48 kWh) option from the product configuration menu before checkout.\u003c\/p\u003e\n\u003ch3\u003eCan I add batteries later?\u003c\/h3\u003e\n\u003cp\u003eYes — per EG4 the WallMount 314Ah parallels up to 32 units, and Auto-ID addressing configures new batteries automatically. Most owners start with one or two and expand.\u003c\/p\u003e\n\u003ch3\u003eAre solar panels included?\u003c\/h3\u003e\n\u003cp\u003eNo. Panels, racking, and array wiring are sized to your roof or ground mount and sold separately. The kit operates as grid-charged battery backup without any solar attached.\u003c\/p\u003e\n\u003ch3\u003eHow much power do I get during an outage?\u003c\/h3\u003e\n\u003cp\u003ePer EG4, the FlexBOSS18 delivers 10 kW continuous from battery alone. One battery supports about 10.2 kW of discharge (200A), so even the single-battery configuration can feed the inverter's full battery-mode output.\u003c\/p\u003e\n\u003ch3\u003eDo I need the GridBoss?\u003c\/h3\u003e\n\u003cp\u003eNot for a basic partial-home backup or off-grid build. Per EG4, adding GridBoss brings AC coupling, smart load control, and generator integration for whole-home microgrid setups.\u003c\/p\u003e\n\u003ch3\u003eShould I pick the All-Weather or Indoor kit?\u003c\/h3\u003e\n\u003cp\u003eChoose All-Weather (this kit) when batteries mount outside or in weather-exposed spaces. If they will live in a garage or basement, the Indoor kit uses a lighter battery that per EG4 forms a UL9540 system with the FlexBOSS18.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eSizing between 16, 32, and 48 kWh — or between the FlexBOSS18 and 21? Call OffGrid Horizon at (302) 496-3554 and our family-owned team will walk your loads with you before you order.\u003c\/em\u003e\u003c\/p\u003e","brand":"EG4","offers":[{"title":"1 × 16 kWh All-Weather","offer_id":49051035238555,"sku":"K0286","price":7114.97,"currency_code":"USD","in_stock":true},{"title":"2 × 16 kWh All-Weather — 32 kWh","offer_id":49051035271323,"sku":"K0287","price":11224.94,"currency_code":"USD","in_stock":true},{"title":"3 × 16 kWh All-Weather — 48 kWh","offer_id":49051035304091,"sku":"K0288","price":15334.91,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/files\/314Ah-All-Weather-Flexboss18-scaled.png?v=1784676308"},{"product_id":"eg4-flexboss21-wallmount-314ah-all-weather-battery-kit-16-48-kwh-home-ess","title":"EG4 FlexBOSS21 + WallMount 314Ah All-Weather Battery Kit | 16–48 kWh Home ESS","description":"\u003cp\u003eThis kit pairs the EG4 FlexBOSS21 hybrid inverter — up to 21 kW of usable PV input and 16 kW of AC output with solar contribution per EG4 — with the EG4 WallMount 314Ah All-Weather battery, an IP67-rated 16 kWh unit built for indoor or outdoor mounting. Configure one to three batteries for 16, 32, or 48 kWh of storage, all communicating in closed-loop within a single-manufacturer system. OffGrid Horizon is a family-owned authorized EG4 dealer, and every kit ships with full manufacturer warranty support.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Is For\u003c\/h2\u003e\n\u003cp\u003eLarger homes and heavier simultaneous loads: central air plus a well pump plus a range, shop tools, or a larger solar array that would outgrow the FlexBOSS18. Per EG4, the FlexBOSS21 accepts up to 5 PV strings and passes through 90A of utility power at 120\/240V, making it the higher-headroom choice in the FlexBOSS line — with batteries that can mount outdoors beside it.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eUp to 21 kW of usable PV input\u003c\/strong\u003e across up to 5 strings per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e16 kW AC output with solar contribution; 12 kW continuous from battery alone\u003c\/strong\u003e per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e90A grid feed-through at 120\/240V\u003c\/strong\u003e per EG4 for whole-home pass-through wiring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIP67 all-weather batteries\u003c\/strong\u003e — 16 kWh per unit, wall- or floor-mounted, indoor or outdoor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClosed-loop communication\u003c\/strong\u003e between inverter and batteries over CAN\/RS485, with Auto-ID addressing as you add units\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e10,000-cycle battery rating\u003c\/strong\u003e at 80% depth of discharge per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrid-tied, backup, and off-grid operating modes\u003c\/strong\u003e with app-based remote monitoring\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy EG4\u003c\/h2\u003e\n\u003cp\u003eEG4 Electronics is a Texas-based manufacturer that builds both halves of this system, publishes full spec sheets and test data, and backs the inverter and batteries with 10-year warranties. One engineering team, one support line, one communication protocol — no cross-brand compatibility guesswork.\u003c\/p\u003e\n\n\u003ch2\u003eWhat's In the Kit\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1 x EG4 FlexBOSS21 hybrid inverter\u003c\/strong\u003e — split-phase 120\/240V, UL3141 and UL1741 certified per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1, 2, or 3 x EG4 WallMount 314Ah All-Weather batteries\u003c\/strong\u003e (16 kWh each) — the listed configuration includes one battery; select your capacity from the product options\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eSolar panels, racking, and array wiring are site-specific and sold separately. The system also operates as battery backup without solar.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eInverter\u003c\/td\u003e\n\u003ctd\u003eEG4 FlexBOSS21 hybrid, split-phase 120\/240V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePV input\u003c\/td\u003e\n\u003ctd\u003eUp to 21 kW usable, up to 5 strings, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAC output\u003c\/td\u003e\n\u003ctd\u003e16 kW with solar contribution; 12 kW from battery alone, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGrid feed-through\u003c\/td\u003e\n\u003ctd\u003e90A at 120\/240V, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInverter certifications\u003c\/td\u003e\n\u003ctd\u003eUL3141; UL1741, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInverter enclosure\u003c\/td\u003e\n\u003ctd\u003eNEMA 4X, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery\u003c\/td\u003e\n\u003ctd\u003eEG4 WallMount 314Ah All-Weather, 51.2V, 16 kWh nominal per unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCapacity options\u003c\/td\u003e\n\u003ctd\u003e16 \/ 32 \/ 48 kWh (1, 2, or 3 batteries)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery output\u003c\/td\u003e\n\u003ctd\u003e200A max continuous discharge per unit, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery enclosure\u003c\/td\u003e\n\u003ctd\u003eIP67 — indoor or outdoor mounting\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery certifications\u003c\/td\u003e\n\u003ctd\u003eUL1973; UL9540A, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery cycle life\u003c\/td\u003e\n\u003ctd\u003e10,000 cycles at 80% DoD, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery dimensions \/ weight\u003c\/td\u003e\n\u003ctd\u003e34.6 x 21.7 x 9.3 in \/ 309 lb per unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication\u003c\/td\u003e\n\u003ctd\u003eClosed-loop CAN\/RS485; app-based remote monitoring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003eInverter 10 years; batteries 10 years or 10,000 cycles, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBase SKU\u003c\/td\u003e\n\u003ctd\u003eK0280\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eGrid-Tied, Backup, or Off-Grid\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eGrid-tied:\u003c\/strong\u003e the FlexBOSS21 manages solar production, battery charging, and export under UL1741 interconnection rules — your utility and AHJ govern export permissions. \u003cstrong\u003eBackup:\u003c\/strong\u003e when the grid drops, the system transfers to battery power; if you chose the 21 for its output headroom, plan storage to match, since heavier loads draw a bank down faster — 32 or 48 kWh suits whole-home coverage. \u003cstrong\u003eOff-grid:\u003c\/strong\u003e the same hardware runs fully off-grid, sized by your daily load and sun hours. For whole-home microgrid control — AC coupling, smart load management, and generator integration per EG4 — add the \u003ca href=\"\/products\/eg4-gridboss-200a-mid-microgrid-interconnection-device\"\u003eEG4 GridBoss 200A MID\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eInverter Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe batteries in this kit run closed-loop with the included \u003ca href=\"\/products\/eg4-flexboss21-hybrid-solar-inverter-21-kw-pv-16-kw-ac-split-phase-4-mppt\"\u003eEG4 FlexBOSS21 hybrid inverter\u003c\/a\u003e, so state-of-charge and charge parameters stay coordinated out of the box. Individual \u003ca href=\"\/products\/eg4-wallmount-314ah-all-weather-battery-48v-16-kwh\"\u003eWallMount 314Ah All-Weather batteries\u003c\/a\u003e are available separately when you are ready to expand the bank.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eInstallation must be performed by a licensed electrician — the inverter interconnects with your main panel and, in grid-tied modes, with the utility, and energy storage installations require local permits and inspection. Each battery weighs 309 lb and mounts to the wall or floor per EG4's manual; anchor wall-mounted units into structural framing and plan for lifting equipment. Follow EG4's installation manuals for clearances, torque values, and conductor sizing.\u003c\/p\u003e\n\n\u003ch2\u003eWarranty \u0026amp; Support\u003c\/h2\u003e\n\u003cp\u003ePer EG4, the FlexBOSS21 carries a 10-year warranty and each WallMount battery is covered for 10 years or 10,000 cycles, whichever comes first. Register your equipment with EG4 after purchase and keep your OffGrid Horizon invoice — as an authorized dealer, our records document your coverage. For warranty or configuration help, call us at (302) 496-3554.\u003c\/p\u003e\n\n\u003ch2\u003eShipping\u003c\/h2\u003e\n\u003cp\u003eKits ship by LTL freight on pallets within the United States, curbside with a liftgate. Count every piece against the packing list and inspect for damage before signing the delivery receipt — note any issues with the driver to preserve your freight claim.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eHow many batteries are included?\u003c\/h3\u003e\n\u003cp\u003eThe base configuration includes one 16 kWh battery. Select the 2-battery (32 kWh) or 3-battery (48 kWh) option from the product configuration menu before checkout.\u003c\/p\u003e\n\u003ch3\u003eFlexBOSS21 or FlexBOSS18?\u003c\/h3\u003e\n\u003cp\u003ePer EG4, the 21 offers more PV input (21 kW vs 18 kW), more strings (5 vs 4), and more output (16 kW with solar, 12 kW battery-only, vs 13 kW and 10 kW). Choose the 21 for larger homes, heavy 240V loads, or bigger arrays; the FlexBOSS18 kit covers moderate loads with the same batteries.\u003c\/p\u003e\n\u003ch3\u003eHow much power do I get from batteries at night or in an outage?\u003c\/h3\u003e\n\u003cp\u003ePer EG4, 12 kW continuous from battery alone. One battery sustains about 10.2 kW of discharge (200A), so plan on two or more batteries to use the inverter's full battery-mode output.\u003c\/p\u003e\n\u003ch3\u003eCan I add batteries later?\u003c\/h3\u003e\n\u003cp\u003eYes — per EG4 the WallMount 314Ah parallels up to 32 units, and Auto-ID addressing configures new batteries automatically.\u003c\/p\u003e\n\u003ch3\u003eAre solar panels included?\u003c\/h3\u003e\n\u003cp\u003eNo. Panels, racking, and array wiring are sized to your site and sold separately. The kit operates as grid-charged battery backup without any solar attached.\u003c\/p\u003e\n\u003ch3\u003eDo I need the GridBoss?\u003c\/h3\u003e\n\u003cp\u003eNot for a basic partial-home backup or off-grid build. Per EG4, adding GridBoss brings AC coupling, smart load control, and generator integration for whole-home microgrid setups.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eDeciding how many batteries the FlexBOSS21 really needs for your loads? Call OffGrid Horizon at (302) 496-3554 and our family-owned team will run the numbers with you.\u003c\/em\u003e\u003c\/p\u003e","brand":"EG4","offers":[{"title":"1 × 16 kWh All-Weather","offer_id":49051042119835,"sku":"K0280","price":7514.97,"currency_code":"USD","in_stock":true},{"title":"2 × 16 kWh All-Weather — 32 kWh","offer_id":49051042152603,"sku":"K0281","price":11624.94,"currency_code":"USD","in_stock":true},{"title":"3 × 16 kWh All-Weather — 48 kWh","offer_id":49051042185371,"sku":"K0282","price":15734.91,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/files\/314Ah-All-Weather-Flexboss21-1-scaled.png?v=1784676335"},{"product_id":"eg4-flexboss18-wallmount-314ah-indoor-battery-kit-16-48-kwh-self-heating","title":"EG4 FlexBOSS18 + WallMount 314Ah Indoor Battery Kit | 16–48 kWh | Self-Heating","description":"\u003cp\u003eThis kit pairs the EG4 FlexBOSS18 hybrid inverter — up to 18 kW of PV input and 13 kW of continuous split-phase AC output per EG4 — with the EG4 WallMount 314Ah Indoor battery, a self-heating 16 kWh unit built for garages, basements, and utility rooms. Per EG4, this battery-and-inverter pairing carries the UL9540 energy storage system designation. Configure one to three batteries for 16, 32, or 48 kWh. OffGrid Horizon is a family-owned authorized EG4 dealer, and every kit ships with full manufacturer warranty support.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Is For\u003c\/h2\u003e\n\u003cp\u003eHomeowners installing storage indoors — a garage wall, a basement utility corner — who want a matched single-brand system with the permitting documentation many building departments ask for. Per EG4, the WallMount Indoor forms a UL9540 system with the FlexBOSS18, and its self-heating cells keep charging available when an unheated garage drops below freezing. If your loads are typical residential, the FlexBOSS18's 13 kW output covers most homes.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eUL9540 system designation with the FlexBOSS18\u003c\/strong\u003e, plus UL1973 certification and UL9540A test data on the battery — exactly as EG4 publishes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSelf-heating batteries\u003c\/strong\u003e — a 448W internal heater activates at or below 32°F per EG4, so winter does not stop charging in unheated spaces\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUp to 18 kW of PV input\u003c\/strong\u003e (600VDC max, up to 4 strings per EG4) with 13 kW continuous split-phase 120\/240V output\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e10 kW continuous output from battery alone\u003c\/strong\u003e per EG4 — the figure that matters at night and during outages\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e16 kWh per battery, 10,000-cycle rating\u003c\/strong\u003e at 80% depth of discharge per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClosed-loop communication\u003c\/strong\u003e over CAN\/RS485 with app-based remote monitoring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e293.2 lb per battery\u003c\/strong\u003e — the lightest 16 kWh unit in the WallMount line, wall- or floor-mounted\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy EG4\u003c\/h2\u003e\n\u003cp\u003eEG4 Electronics is a Texas-based manufacturer that builds both halves of this system, publishes full spec sheets and fire-safety test data, and backs the inverter and batteries with 10-year warranties. Because one company engineers the pairing, the UL9540 system documentation covers the exact hardware in this kit.\u003c\/p\u003e\n\n\u003ch2\u003eWhat's In the Kit\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1 x EG4 FlexBOSS18 hybrid inverter\u003c\/strong\u003e — split-phase 120\/240V, UL3141 and UL1741 certified per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1, 2, or 3 x EG4 WallMount 314Ah Indoor batteries\u003c\/strong\u003e (16 kWh each) — the listed configuration includes one battery; select your capacity from the product options\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eSolar panels, racking, and array wiring are site-specific and sold separately. The system also operates as battery backup without solar.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eInverter\u003c\/td\u003e\n\u003ctd\u003eEG4 FlexBOSS18 hybrid, split-phase 120\/240V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePV input\u003c\/td\u003e\n\u003ctd\u003eUp to 18 kW (STC), 600VDC max, up to 4 strings, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAC output\u003c\/td\u003e\n\u003ctd\u003e13 kW continuous (grid-tied with solar contribution); 10 kW from battery alone, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInverter certifications\u003c\/td\u003e\n\u003ctd\u003eUL3141; UL1741, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery\u003c\/td\u003e\n\u003ctd\u003eEG4 WallMount 314Ah Indoor, 51.2V, 16 kWh nominal per unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCapacity options\u003c\/td\u003e\n\u003ctd\u003e16 \/ 32 \/ 48 kWh (1, 2, or 3 batteries)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery output\u003c\/td\u003e\n\u003ctd\u003e200A max continuous discharge per unit, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery enclosure\u003c\/td\u003e\n\u003ctd\u003eIP20 — indoor installation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery certifications\u003c\/td\u003e\n\u003ctd\u003eUL1973; UL9540A; UL9540 with FlexBOSS18, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSelf-heating\u003c\/td\u003e\n\u003ctd\u003e448W heater, on at 32°F or below, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery cycle life\u003c\/td\u003e\n\u003ctd\u003e10,000 cycles at 80% DoD, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery dimensions \/ weight\u003c\/td\u003e\n\u003ctd\u003e34.1 x 18.1 x 9.6 in \/ 293.2 lb per unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication\u003c\/td\u003e\n\u003ctd\u003eClosed-loop CAN\/RS485; app-based remote monitoring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003eInverter 10 years; batteries 10 years or 10,000 cycles, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBase SKU\u003c\/td\u003e\n\u003ctd\u003eK0216\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eGrid-Tied, Backup, or Off-Grid\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eGrid-tied:\u003c\/strong\u003e the FlexBOSS18 manages solar production, battery charging, and export under UL1741 interconnection rules — your utility and AHJ govern export permissions. \u003cstrong\u003eBackup:\u003c\/strong\u003e when the grid drops, the system transfers to battery power; one battery (16 kWh) carries essential circuits overnight, while 32 or 48 kWh supports whole-home coverage or multi-day outages. \u003cstrong\u003eOff-grid:\u003c\/strong\u003e the same hardware runs fully off-grid, sized by your daily load and sun hours. For whole-home microgrid control — AC coupling, smart load management, and generator integration per EG4 — add the \u003ca href=\"\/products\/eg4-gridboss-200a-mid-microgrid-interconnection-device\"\u003eEG4 GridBoss 200A MID\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eInverter Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe batteries in this kit run closed-loop with the included \u003ca href=\"\/products\/eg4-flexboss18-hybrid-solar-inverter-18-kw-pv-13-kw-ac-split-phase-3-mppt\"\u003eEG4 FlexBOSS18 hybrid inverter\u003c\/a\u003e, so state-of-charge and charge parameters stay coordinated out of the box — and per EG4 the pairing carries the UL9540 system designation. Individual \u003ca href=\"\/products\/eg4-wallmount-314ah-indoor-battery-48v-16-kwh-ul9540a-self-heating\"\u003eWallMount 314Ah Indoor batteries\u003c\/a\u003e are available separately when you are ready to expand.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eInstallation must be performed by a licensed electrician — the inverter interconnects with your main panel and, in grid-tied modes, with the utility, and energy storage installations require local permits and inspection. Each battery weighs 293.2 lb and mounts to the wall or floor per EG4's manual; anchor wall-mounted units into structural framing and plan for lifting equipment. The batteries are IP20 rated and must be installed indoors; the NEMA 4X inverter can mount outside nearby if preferred. Follow EG4's installation manuals for clearances and torque values, and confirm indoor energy-storage placement rules with your building department.\u003c\/p\u003e\n\n\u003ch2\u003eWarranty \u0026amp; Support\u003c\/h2\u003e\n\u003cp\u003ePer EG4, the FlexBOSS18 carries a 10-year warranty and each WallMount Indoor battery is covered for 10 years or 10,000 cycles, whichever comes first. Register your equipment with EG4 after purchase and keep your OffGrid Horizon invoice — as an authorized dealer, our records document your coverage. For warranty or configuration help, call us at (302) 496-3554.\u003c\/p\u003e\n\n\u003ch2\u003eShipping\u003c\/h2\u003e\n\u003cp\u003eKits ship by LTL freight on pallets within the United States, curbside with a liftgate. Count every piece against the packing list and inspect for damage before signing the delivery receipt — note any issues with the driver to preserve your freight claim.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eHow many batteries are included?\u003c\/h3\u003e\n\u003cp\u003eThe base configuration includes one 16 kWh battery. Select the 2-battery (32 kWh) or 3-battery (48 kWh) option from the product configuration menu before checkout.\u003c\/p\u003e\n\u003ch3\u003eWhat does the UL9540 system designation mean for permitting?\u003c\/h3\u003e\n\u003cp\u003eUL1973 covers the battery, UL9540A is a fire-safety test method, and UL9540 covers the complete energy storage system. Per EG4, this battery achieves UL9540 when paired with the FlexBOSS18 — documentation many building departments request for indoor installations.\u003c\/p\u003e\n\u003ch3\u003eWhy do indoor batteries need self-heating?\u003c\/h3\u003e\n\u003cp\u003eLiFePO4 cells cannot accept charge below 32°F, and detached garages and unheated basements routinely drop below freezing. Per EG4, the heater switches on at 32°F and off at 37°F, keeping charging available all winter.\u003c\/p\u003e\n\u003ch3\u003eCan I add batteries later?\u003c\/h3\u003e\n\u003cp\u003eYes — per EG4 the WallMount 314Ah Indoor parallels up to 32 units. Most owners start with one or two and expand.\u003c\/p\u003e\n\u003ch3\u003eAre solar panels included?\u003c\/h3\u003e\n\u003cp\u003eNo. Panels, racking, and array wiring are sized to your site and sold separately. The kit operates as grid-charged battery backup without any solar attached.\u003c\/p\u003e\n\u003ch3\u003eShould I pick the Indoor or All-Weather kit?\u003c\/h3\u003e\n\u003cp\u003eIndoor (this kit) when batteries live in a garage, basement, or utility room — lighter units plus the published UL9540 pairing. All-Weather when batteries must mount outside in an IP67 enclosure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eNot sure what your inspector will want to see, or how many batteries your loads need? Call OffGrid Horizon at (302) 496-3554 — our family-owned team helps with both before you order.\u003c\/em\u003e\u003c\/p\u003e","brand":"EG4","offers":[{"title":"1 × 16 kWh Indoor","offer_id":49051043791003,"sku":"K0216","price":6692.97,"currency_code":"USD","in_stock":true},{"title":"2 × 16 kWh Indoor — 32 kWh","offer_id":49051043823771,"sku":"K0217","price":10350.94,"currency_code":"USD","in_stock":true},{"title":"3 × 16 kWh Indoor — 48 kWh","offer_id":49051043856539,"sku":"K0218","price":14008.91,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/files\/EG4-314Ah-Indoor-Flexboss-18-1.png?v=1784676361"},{"product_id":"eg4-flexboss21-wallmount-314ah-indoor-battery-kit-16-48-kwh-self-heating","title":"EG4 FlexBOSS21 + WallMount 314Ah Indoor Battery Kit | 16–48 kWh | Self-Heating","description":"\u003cp\u003eThis kit pairs the EG4 FlexBOSS21 hybrid inverter — up to 21 kW of usable PV input and 16 kW of AC output with solar contribution per EG4 — with the EG4 WallMount 314Ah Indoor battery, a self-heating 16 kWh unit built for garages, basements, and utility rooms. Per EG4, this battery-and-inverter pairing carries the UL9540 energy storage system designation. Configure one to three batteries for 16, 32, or 48 kWh. OffGrid Horizon is a family-owned authorized EG4 dealer, and every kit ships with full manufacturer warranty support.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Is For\u003c\/h2\u003e\n\u003cp\u003eLarger homes with indoor battery placement: heavier simultaneous 240V loads (central air, well pump, range, shop equipment) or bigger solar arrays that would outgrow the FlexBOSS18, combined with garage or basement battery mounting where the Indoor model's lighter weight, self-heating, and published UL9540 pairing fit best. Per EG4, the FlexBOSS21 accepts up to 5 PV strings and passes through 90A of utility power at 120\/240V.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eUL9540 system designation with the FlexBOSS21\u003c\/strong\u003e, plus UL1973 certification and UL9540A test data on the battery — exactly as EG4 publishes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUp to 21 kW of usable PV input\u003c\/strong\u003e across up to 5 strings per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e16 kW AC output with solar contribution; 12 kW continuous from battery alone\u003c\/strong\u003e per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSelf-heating batteries\u003c\/strong\u003e — a 448W internal heater activates at or below 32°F per EG4, so winter does not stop charging in unheated spaces\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e16 kWh per battery, 10,000-cycle rating\u003c\/strong\u003e at 80% depth of discharge per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e90A grid feed-through at 120\/240V\u003c\/strong\u003e per EG4 for whole-home pass-through wiring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClosed-loop communication\u003c\/strong\u003e over CAN\/RS485 with app-based remote monitoring\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy EG4\u003c\/h2\u003e\n\u003cp\u003eEG4 Electronics is a Texas-based manufacturer that builds both halves of this system, publishes full spec sheets and fire-safety test data, and backs the inverter and batteries with 10-year warranties. Because one company engineers the pairing, the UL9540 system documentation covers the exact hardware in this kit.\u003c\/p\u003e\n\n\u003ch2\u003eWhat's In the Kit\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1 x EG4 FlexBOSS21 hybrid inverter\u003c\/strong\u003e — split-phase 120\/240V, UL3141 and UL1741 certified per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1, 2, or 3 x EG4 WallMount 314Ah Indoor batteries\u003c\/strong\u003e (16 kWh each) — the listed configuration includes one battery; select your capacity from the product options\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eSolar panels, racking, and array wiring are site-specific and sold separately. The system also operates as battery backup without solar.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eInverter\u003c\/td\u003e\n\u003ctd\u003eEG4 FlexBOSS21 hybrid, split-phase 120\/240V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePV input\u003c\/td\u003e\n\u003ctd\u003eUp to 21 kW usable, up to 5 strings, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAC output\u003c\/td\u003e\n\u003ctd\u003e16 kW with solar contribution; 12 kW from battery alone, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGrid feed-through\u003c\/td\u003e\n\u003ctd\u003e90A at 120\/240V, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInverter certifications\u003c\/td\u003e\n\u003ctd\u003eUL3141; UL1741, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery\u003c\/td\u003e\n\u003ctd\u003eEG4 WallMount 314Ah Indoor, 51.2V, 16 kWh nominal per unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCapacity options\u003c\/td\u003e\n\u003ctd\u003e16 \/ 32 \/ 48 kWh (1, 2, or 3 batteries)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery output\u003c\/td\u003e\n\u003ctd\u003e200A max continuous discharge per unit, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery enclosure\u003c\/td\u003e\n\u003ctd\u003eIP20 — indoor installation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery certifications\u003c\/td\u003e\n\u003ctd\u003eUL1973; UL9540A; UL9540 with FlexBOSS21, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSelf-heating\u003c\/td\u003e\n\u003ctd\u003e448W heater, on at 32°F or below, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery cycle life\u003c\/td\u003e\n\u003ctd\u003e10,000 cycles at 80% DoD, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery dimensions \/ weight\u003c\/td\u003e\n\u003ctd\u003e34.1 x 18.1 x 9.6 in \/ 293.2 lb per unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication\u003c\/td\u003e\n\u003ctd\u003eClosed-loop CAN\/RS485; app-based remote monitoring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003eInverter 10 years; batteries 10 years or 10,000 cycles, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBase SKU\u003c\/td\u003e\n\u003ctd\u003eK0210\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eGrid-Tied, Backup, or Off-Grid\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eGrid-tied:\u003c\/strong\u003e the FlexBOSS21 manages solar production, battery charging, and export under UL1741 interconnection rules — your utility and AHJ govern export permissions. \u003cstrong\u003eBackup:\u003c\/strong\u003e when the grid drops, the system transfers to battery power; if you chose the 21 for its output headroom, plan storage to match — heavier loads draw a bank down faster, so 32 or 48 kWh suits whole-home coverage. \u003cstrong\u003eOff-grid:\u003c\/strong\u003e the same hardware runs fully off-grid, sized by your daily load and sun hours. For whole-home microgrid control — AC coupling, smart load management, and generator integration per EG4 — add the \u003ca href=\"\/products\/eg4-gridboss-200a-mid-microgrid-interconnection-device\"\u003eEG4 GridBoss 200A MID\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eInverter Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe batteries in this kit run closed-loop with the included \u003ca href=\"\/products\/eg4-flexboss21-hybrid-solar-inverter-21-kw-pv-16-kw-ac-split-phase-4-mppt\"\u003eEG4 FlexBOSS21 hybrid inverter\u003c\/a\u003e, so state-of-charge and charge parameters stay coordinated out of the box — and per EG4 the pairing carries the UL9540 system designation. Individual \u003ca href=\"\/products\/eg4-wallmount-314ah-indoor-battery-48v-16-kwh-ul9540a-self-heating\"\u003eWallMount 314Ah Indoor batteries\u003c\/a\u003e are available separately when you are ready to expand.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eInstallation must be performed by a licensed electrician — the inverter interconnects with your main panel and, in grid-tied modes, with the utility, and energy storage installations require local permits and inspection. Each battery weighs 293.2 lb and mounts to the wall or floor per EG4's manual; anchor wall-mounted units into structural framing and plan for lifting equipment. The batteries are IP20 rated and must be installed indoors; the NEMA 4X inverter can mount outside nearby if preferred. Follow EG4's installation manuals for clearances and torque values, and confirm indoor energy-storage placement rules with your building department.\u003c\/p\u003e\n\n\u003ch2\u003eWarranty \u0026amp; Support\u003c\/h2\u003e\n\u003cp\u003ePer EG4, the FlexBOSS21 carries a 10-year warranty and each WallMount Indoor battery is covered for 10 years or 10,000 cycles, whichever comes first. Register your equipment with EG4 after purchase and keep your OffGrid Horizon invoice — as an authorized dealer, our records document your coverage. For warranty or configuration help, call us at (302) 496-3554.\u003c\/p\u003e\n\n\u003ch2\u003eShipping\u003c\/h2\u003e\n\u003cp\u003eKits ship by LTL freight on pallets within the United States, curbside with a liftgate. Count every piece against the packing list and inspect for damage before signing the delivery receipt — note any issues with the driver to preserve your freight claim.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eHow many batteries are included?\u003c\/h3\u003e\n\u003cp\u003eThe base configuration includes one 16 kWh battery. Select the 2-battery (32 kWh) or 3-battery (48 kWh) option from the product configuration menu before checkout.\u003c\/p\u003e\n\u003ch3\u003eHow much power do I get from batteries at night or in an outage?\u003c\/h3\u003e\n\u003cp\u003ePer EG4, 12 kW continuous from battery alone. One battery sustains about 10.2 kW of discharge (200A), so plan on two or more batteries to use the inverter's full battery-mode output.\u003c\/p\u003e\n\u003ch3\u003eWhat does the UL9540 system designation mean for permitting?\u003c\/h3\u003e\n\u003cp\u003eUL1973 covers the battery, UL9540A is a fire-safety test method, and UL9540 covers the complete energy storage system. Per EG4, this battery achieves UL9540 when paired with the FlexBOSS21 — documentation many building departments request for indoor installations.\u003c\/p\u003e\n\u003ch3\u003eFlexBOSS21 or FlexBOSS18?\u003c\/h3\u003e\n\u003cp\u003ePer EG4, the 21 offers more PV input (21 kW vs 18 kW), more strings (5 vs 4), and more output (16 kW with solar, 12 kW battery-only, vs 13 kW and 10 kW). Choose the 21 for larger homes, heavy 240V loads, or bigger arrays; the FlexBOSS18 Indoor kit covers moderate loads with the same batteries.\u003c\/p\u003e\n\u003ch3\u003eCan I add batteries later?\u003c\/h3\u003e\n\u003cp\u003eYes — per EG4 the WallMount 314Ah Indoor parallels up to 32 units. Most owners start with one or two and expand.\u003c\/p\u003e\n\u003ch3\u003eAre solar panels included?\u003c\/h3\u003e\n\u003cp\u003eNo. Panels, racking, and array wiring are sized to your site and sold separately. The kit operates as grid-charged battery backup without any solar attached.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eMatching battery count to the FlexBOSS21's output for your home? Call OffGrid Horizon at (302) 496-3554 — our family-owned team will run your loads before you order.\u003c\/em\u003e\u003c\/p\u003e","brand":"EG4","offers":[{"title":"1 × 16 kWh Indoor","offer_id":49051044741275,"sku":"K0210","price":7092.97,"currency_code":"USD","in_stock":true},{"title":"2 × 16 kWh Indoor — 32 kWh","offer_id":49051044774043,"sku":"K0211","price":10750.94,"currency_code":"USD","in_stock":true},{"title":"3 × 16 kWh Indoor — 48 kWh","offer_id":49051044806811,"sku":"K0212","price":14408.91,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/files\/FLEXBOSS21-EG4-314Ah.png?v=1784676386"},{"product_id":"eg4-6000xp-off-grid-inverter-6-kw-output-8-kw-pv-input-split-phase","title":"EG4 6000XP Off-Grid Inverter | 6 kW Output | 8 kW PV Input | Split-Phase","description":"\u003cp\u003eThe EG4 6000XP is an all-in-one off-grid inverter that combines a 6,000W split-phase 120\/240V inverter, dual MPPT solar charge controllers, and a battery charger in a single wall-mounted unit. Per EG4, it accepts up to 8,000W of solar input (4,000W per MPPT) and charges a 48V battery bank at up to 125A from solar, with an AC input for charging from a generator or the grid where available. There is no separate charge controller to buy, wire, or configure.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Is For\u003c\/h2\u003e\n\u003cp\u003eCabins, tiny homes, homesteads, well houses, and workshops running essential-to-moderate loads without a utility connection — or properties that want battery-based power independent of the grid. It delivers true 120\/240V split-phase output, so standard North American panels and 240V equipment such as well pumps work without an autotransformer. If your property runs heavy simultaneous loads like central air plus shop equipment, look at the EG4 12000XP V2 instead.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e6,000W continuous split-phase 120\/240V output\u003c\/strong\u003e, with surge capacity of 12,000W for roughly 3.5 seconds per EG4's spec sheet — headroom for motor starts\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e8,000W PV input across two MPPTs\u003c\/strong\u003e (17A rated \/ 25A Isc each, 120–385 VDC MPPT range, 480 VDC max input)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48V battery charging up to 125A from solar\u003c\/strong\u003e and up to 115A from the AC input, with closed-loop communications for compatible lithium batteries\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eParallel up to 16 units\u003c\/strong\u003e per EG4 for larger systems as your loads grow\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFast internal transfer\u003c\/strong\u003e between AC input and inverter output — under 15 ms for a single unit per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEG4 Connect monitoring\u003c\/strong\u003e over Wi-Fi, with RS485 and CAN communication ports\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUL 1741 listed\u003c\/strong\u003e and FCC Part 15 Class B per EG4's published spec sheet\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy EG4\u003c\/h2\u003e\n\u003cp\u003eEG4 Electronics is a US-based manufacturer that publishes full spec sheets, manuals, and wiring diagrams for its equipment and maintains US-based technical support. Its inverters and batteries are designed to work together with closed-loop communications, so the inverter charges based on data reported by the battery rather than voltage assumptions.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cp\u003eSpecifications below are per EG4's published 6000XP spec sheet.\u003c\/p\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eContinuous output\u003c\/td\u003e\n\u003ctd\u003e6,000W, split-phase 120\/240VAC, 60 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurge capacity\u003c\/td\u003e\n\u003ctd\u003e12,000W (~3.5 s) \/ 11,000W (~5 s)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax continuous output current\u003c\/td\u003e\n\u003ctd\u003e37.5A @ 240VAC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePV input\u003c\/td\u003e\n\u003ctd\u003e8,000W max utilized (4,000W per MPPT), 2 MPPTs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMPPT voltage range\u003c\/td\u003e\n\u003ctd\u003e120–385 VDC (startup 100 VDC ± 10; max input 480 VDC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePV current per MPPT\u003c\/td\u003e\n\u003ctd\u003e17A rated \/ 25A short-circuit (Isc)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery voltage\u003c\/td\u003e\n\u003ctd\u003e48V nominal; 46.4–60 VDC lithium (38.4–60 VDC lead-acid)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax charge current\u003c\/td\u003e\n\u003ctd\u003e125A solar \/ 115A AC; 140A max discharge\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAC input\u003c\/td\u003e\n\u003ctd\u003e120\/240VAC (L1\/L2\/N), up to 9,000W — grid or generator\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransfer time\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;15 ms single \/ \u0026lt;30 ms parallel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIdle consumption\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;30W with PV; ~50W on battery\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMPPT efficiency\u003c\/td\u003e\n\u003ctd\u003e99% (93% battery charge\/discharge efficiency)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallel capability\u003c\/td\u003e\n\u003ctd\u003eUp to 16 units\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCertifications\u003c\/td\u003e\n\u003ctd\u003eUL 1741; FCC Part 15 Class B\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnclosure \/ environment\u003c\/td\u003e\n\u003ctd\u003eIP20 (indoor); 32–113 °F operating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions \/ weight\u003c\/td\u003e\n\u003ctd\u003e18 x 25.5 x 5.25 in; 52.9 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunications \/ monitoring\u003c\/td\u003e\n\u003ctd\u003eRS485, Wi-Fi, CAN; EG4 Connect app\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e5 years per EG4 (registration required within first year)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eINV026\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eOff-Grid by Design\u003c\/h2\u003e\n\u003cp\u003eThe 6000XP is an off-grid inverter: it does not export power to the utility grid or participate in net metering. Practically, that means no utility interconnection agreement is required for the inverter's grid-export function — the AC input is used only to charge batteries and pass power through to your loads from a generator or the grid. Solar you produce is used to charge batteries and run loads; excess production beyond that is curtailed rather than sold back. If selling power to your utility matters to you, consider a hybrid model such as the EG4 FlexBOSS18 or 18kPV. Note that connecting any inverter to premises wiring still involves local permitting and code compliance.\u003c\/p\u003e\n\n\u003ch2\u003eBattery Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe 6000XP is designed for 48V battery banks and supports closed-loop communications with EG4 batteries, so state of charge comes from the battery's BMS rather than voltage estimates. The \u003ca href=\"\/products\/eg4-wallmount-280ah-all-weather-battery-48v-14-3-kwh-ul1973\"\u003eEG4 WallMount 280Ah all-weather battery (14.3 kWh)\u003c\/a\u003e and the \u003ca href=\"\/products\/eg4-wallmount-314ah-all-weather-battery-48v-16-kwh\"\u003eEG4 WallMount 314Ah all-weather battery (16 kWh)\u003c\/a\u003e are natural pairings; both are 48V wall-mounted LiFePO4 units. Lead-acid banks are also supported within the published voltage range.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eThe 6000XP is wall-mounted and rated IP20, so it belongs indoors or in a protected, dry space. Tying its 120\/240V output into a load panel — grounding, bonding, overcurrent protection, and code compliance — should be performed by a licensed electrician, and most jurisdictions require a permit for this work even off-grid. Plan conductor sizing around the full 37.5A output and the battery cabling around 140A discharge.\u003c\/p\u003e\n\n\u003ch2\u003eWarranty \u0026amp; Support\u003c\/h2\u003e\n\u003cp\u003ePer EG4, the 6000XP carries a 5-year parts-or-product replacement warranty; EG4 requires registration within the first year of purchase or proof of purchase from an authorized distributor. OffGrid Horizon is a family-owned authorized EG4 dealer — if you ever need warranty help, call us at (302) 496-3554 and we will work the process with you and EG4.\u003c\/p\u003e\n\n\u003ch2\u003eShipping\u003c\/h2\u003e\n\u003cp\u003eShips within the contiguous United States. At 52.9 lb boxed, the 6000XP typically ships by ground carrier. Inspect the carton on arrival and note any visible damage with the carrier before signing; contact us right away if anything looks wrong and we will make it right.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eDoes it need solar panels to work?\u003c\/h3\u003e\n\u003cp\u003eNo. It runs as an inverter\/charger from the battery bank alone and can charge from the AC input (generator or grid) when available. Panels are sold separately.\u003c\/p\u003e\n\u003ch3\u003eCan it sell power back to the grid?\u003c\/h3\u003e\n\u003cp\u003eNo. The 6000XP is off-grid by design and does not export to the utility. See the EG4 hybrid models if grid export — subject to utility approval — is a goal.\u003c\/p\u003e\n\u003ch3\u003eWill it start a well pump?\u003c\/h3\u003e\n\u003cp\u003ePer EG4's spec sheet it surges to 12,000W for about 3.5 seconds, which covers many residential pump and motor starts. Check your pump's locked-rotor amps to confirm.\u003c\/p\u003e\n\u003ch3\u003eHow many can I parallel?\u003c\/h3\u003e\n\u003cp\u003ePer EG4, up to 16 units can be paralleled for larger systems.\u003c\/p\u003e\n\u003ch3\u003eCan it charge from a generator?\u003c\/h3\u003e\n\u003cp\u003eYes — the AC input accepts 120\/240V generator power for battery charging and pass-through, up to 9,000W per the spec sheet.\u003c\/p\u003e\n\u003ch3\u003eDoes it work with batteries other than EG4?\u003c\/h3\u003e\n\u003cp\u003eIt supports 48V lithium and lead-acid banks within the published voltage range; closed-loop communication is available with compatible batteries. EG4 WallMount batteries keep everything in one supported ecosystem.\u003c\/p\u003e\n\u003ch3\u003eCan it be installed outdoors?\u003c\/h3\u003e\n\u003cp\u003eThe enclosure is rated IP20, so it needs an indoor or weather-protected location.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eSizing a cabin or homestead system? Call OffGrid Horizon at (302) 496-3554 — we are a family-owned authorized EG4 dealer and can help you match the 6000XP with the right battery bank and array. Browse the full \u003ca href=\"\/collections\/eg4\"\u003eEG4 collection\u003c\/a\u003e for more options.\u003c\/em\u003e\u003c\/p\u003e","brand":"EG4","offers":[{"title":"Default Title","offer_id":49082610745499,"sku":"INV026","price":1574.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/files\/EG4-6000XP-Inverter_a6bb58c0-b312-4d42-9912-0a1254522e07.webp?v=1784902419"},{"product_id":"eg4-18kpv-all-in-one-hybrid-solar-inverter-18-kw-pv-12-kw-ac-split-phase","title":"EG4 18kPV All-in-One Hybrid Solar Inverter | 18 kW PV \/ 12 kW AC | Split-Phase","description":"\u003cp\u003eThe EG4 18kPV is an all-in-one hybrid solar inverter for whole-home systems. Per EG4, it utilizes up to 18,000W of solar across three MPPTs, delivers 12,000W of continuous split-phase 120\/240V output, and charges a 48V battery bank at up to 250A — handling grid-tied operation, backup, and off-grid duty from a single NEMA 4X enclosure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQuestions about configuration or current availability on this model? Call us at (302) 496-3554 before you order\u003c\/strong\u003e — we will confirm the exact package and options for your project.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Is For\u003c\/h2\u003e\n\u003cp\u003eHomeowners building whole-home solar-plus-storage — whether the goal is outage backup, solar self-consumption, or grid export where the utility allows it. The UL 1741 SB listing and California Rule 21 \/ Hawaii Rule 14H compliance published by EG4 matter if your utility requires a grid-support-capable inverter for interconnection. For off-grid-only projects that will never export, the XP series does the job without the interconnection paperwork.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e12,000W continuous split-phase 120\/240V output\u003c\/strong\u003e (50A), with peak capacity of 15,500W for 5 minutes per EG4's spec sheet\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUp to 18,000W of utilized PV\u003c\/strong\u003e across three MPPTs (25A \/ 15A \/ 15A rated), 600 VDC max input\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrid-tied, grid-assist, and off-grid modes\u003c\/strong\u003e per EG4 — export is subject to your utility's interconnection approval\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48V battery charging\/discharging up to 250A\u003c\/strong\u003e with closed-loop communications for compatible batteries\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUL 1741 SA\/SB with PCS CRD and UL 1699B arc-fault protection\u003c\/strong\u003e per EG4's published certifications\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNEMA 4X enclosure\u003c\/strong\u003e rated for outdoor installation, -13 to 140 °F operating range\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eParallel up to 10 units\u003c\/strong\u003e per EG4; built-in Wi-Fi with EG4 monitoring app\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy EG4\u003c\/h2\u003e\n\u003cp\u003eEG4 Electronics is a US-based manufacturer that publishes complete spec sheets, manuals, and wiring diagrams and maintains US-based technical support. The 18kPV is part of an integrated ecosystem: EG4 batteries communicate closed-loop with the inverter, and the EG4 GridBOSS MID lists the 18kPV among its supported hybrid inverters for whole-home backup switching.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cp\u003eSpecifications below are per EG4's published 18kPV spec sheet.\u003c\/p\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eContinuous AC output\u003c\/td\u003e\n\u003ctd\u003e12,000W @ 240V (10,400W @ 208V), 50A max\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak output\u003c\/td\u003e\n\u003ctd\u003e15,500W (5 min) with PV; 13,500W (10 min) without PV\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutput voltage\u003c\/td\u003e\n\u003ctd\u003eSplit-phase 120\/240VAC or 120\/208VAC (L1\/L2\/N)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePV input\u003c\/td\u003e\n\u003ctd\u003e18,000W max utilized, 3 MPPTs (4 string inputs: 2\/1\/1)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMPPT voltage range\u003c\/td\u003e\n\u003ctd\u003e140–500 VDC (startup 100 VDC; max input 600 VDC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePV current per MPPT\u003c\/td\u003e\n\u003ctd\u003e25A \/ 15A \/ 15A rated; 31A \/ 19A \/ 19A Isc\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery voltage\u003c\/td\u003e\n\u003ctd\u003e40–60 VDC (48V-class); EG4 recommends ≥300Ah capacity\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax charge \/ discharge current\u003c\/td\u003e\n\u003ctd\u003e250A \/ 250A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAC input\u003c\/td\u003e\n\u003ctd\u003e120\/240VAC, 50A \/ 12,000W max; 90A generator bypass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransfer time\u003c\/td\u003e\n\u003ctd\u003e20 ms default (10 ms configurable)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEfficiency\u003c\/td\u003e\n\u003ctd\u003e96.9% CEC; 97.5% peak PV-to-grid\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIdle consumption\u003c\/td\u003e\n\u003ctd\u003e~70W normal; ~18W standby\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallel capability\u003c\/td\u003e\n\u003ctd\u003eUp to 10 units\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCertifications\u003c\/td\u003e\n\u003ctd\u003eUL 1741 SA\/SB with PCS CRD; UL 1699B; California Rule 21 Phase I–III; Hawaii Rule 14H\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnclosure \/ environment\u003c\/td\u003e\n\u003ctd\u003eNEMA 4X; -13 to 140 °F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions \/ weight\u003c\/td\u003e\n\u003ctd\u003e34.3 x 20.5 x 11.2 in; 121 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunications \/ monitoring\u003c\/td\u003e\n\u003ctd\u003eRS485, Wi-Fi, CAN; EG4 app and web monitoring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e10-year standard per EG4 (registration required within first year)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eINV024\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eGrid-Tied, Backup, or Off-Grid\u003c\/h2\u003e\n\u003cp\u003eThe 18kPV runs in three ways per EG4. \u003cstrong\u003eGrid-tied:\u003c\/strong\u003e solar serves your loads and charges batteries, and surplus can be exported — but only if your utility approves the interconnection application; export capability and compensation vary by state and utility. \u003cstrong\u003eBackup:\u003c\/strong\u003e when the grid drops, the inverter transfers to battery in 20 ms (10 ms configurable per EG4) and carries the loads it feeds. \u003cstrong\u003eOff-grid:\u003c\/strong\u003e it will run with no utility connection at all, using the 90A generator bypass for extended cloudy stretches. Your installer sets the operating mode and any utility-required grid-support settings at commissioning.\u003c\/p\u003e\n\n\u003ch2\u003eBattery Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe 18kPV manages a 48V-class bank (40–60 VDC) with closed-loop communications to EG4 batteries. The \u003ca href=\"\/products\/eg4-wallmount-314ah-indoor-battery-48v-16-kwh-ul9540a-self-heating\"\u003eEG4 WallMount 314Ah indoor battery (16 kWh, UL9540A-tested, self-heating)\u003c\/a\u003e is a natural pairing, and EG4 recommends at least 300Ah of battery capacity behind this inverter — in practice, two or more 16 kWh WallMount units.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eInstallation is licensed-electrician work: the 18kPV interconnects with your main panel and, in grid-tied modes, with the utility, which requires an interconnection application before the system may export. Residential energy storage is subject to local permitting and inspection. The NEMA 4X enclosure allows outdoor mounting; plan for its 121 lb weight and clearances per EG4's manual. For whole-home backup switching at the service entrance, pair it with the \u003ca href=\"\/products\/eg4-gridboss-200a-mid-microgrid-interconnection-device\"\u003eEG4 GridBOSS 200A MID\u003c\/a\u003e, which lists the 18kPV among its supported inverters.\u003c\/p\u003e\n\n\u003ch2\u003eWarranty \u0026amp; Support\u003c\/h2\u003e\n\u003cp\u003ePer EG4, the 18kPV carries a 10-year standard warranty; EG4 requires registration within the first year of purchase or proof of purchase from an authorized distributor. OffGrid Horizon is a family-owned authorized EG4 dealer — call (302) 496-3554 with sizing, configuration, or warranty questions and you will talk to a person, not a queue.\u003c\/p\u003e\n\n\u003ch2\u003eShipping\u003c\/h2\u003e\n\u003cp\u003eShips within the contiguous United States. At 121 lb, the 18kPV ships LTL freight on a pallet. Inspect packaging before signing the delivery receipt, note any damage with the driver, and call us immediately if something is wrong.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eCan it sell power back to the grid?\u003c\/h3\u003e\n\u003cp\u003eIt is built for grid-interactive operation with UL 1741 SB per EG4 — but actual export depends on your utility approving your interconnection application, and compensation rules vary by state and utility. Confirm with your utility before counting on export revenue.\u003c\/p\u003e\n\u003ch3\u003eDoes it work during a power outage?\u003c\/h3\u003e\n\u003cp\u003eYes — with batteries attached it transfers to backup in 20 ms by default (10 ms configurable) per EG4 and carries the loads it feeds.\u003c\/p\u003e\n\u003ch3\u003eCan it run fully off-grid?\u003c\/h3\u003e\n\u003cp\u003eYes. Off-grid is a supported mode per EG4, and a 90A generator bypass covers extended low-sun periods.\u003c\/p\u003e\n\u003ch3\u003eHow many strings of panels can I connect?\u003c\/h3\u003e\n\u003cp\u003ePer EG4's spec sheet: four string inputs across three MPPTs (2\/1\/1), 600 VDC max, with MPPT current limits of 25A \/ 15A \/ 15A.\u003c\/p\u003e\n\u003ch3\u003eIs a battery required?\u003c\/h3\u003e\n\u003cp\u003eA 48V-class battery bank is central to how the 18kPV operates, and EG4 recommends at least 300Ah of capacity. Talk to us about the right bank for your loads.\u003c\/p\u003e\n\u003ch3\u003eCan I parallel multiple units?\u003c\/h3\u003e\n\u003cp\u003ePer EG4, up to 10 units can be paralleled.\u003c\/p\u003e\n\u003ch3\u003e18kPV or FlexBOSS21?\u003c\/h3\u003e\n\u003cp\u003eBoth are EG4 hybrids. The 18kPV is the established all-in-one with 12 kW output and 3 MPPTs; the FlexBOSS21 offers 16 kW output with PV and pairs with GridBOSS via EG4's newer platform. Call us and we will walk through which fits your service and loads.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eNot sure about configuration on this model? Call OffGrid Horizon at (302) 496-3554 — family-owned, authorized EG4 dealer — or browse the full \u003ca href=\"\/collections\/eg4\"\u003eEG4 collection\u003c\/a\u003e.\u003c\/em\u003e\u003c\/p\u003e","brand":"EG4","offers":[{"title":"Default Title","offer_id":49082611630235,"sku":"INV024","price":4999.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/files\/EG4-12K-18kPV-Inverter-front-V2.png?v=1784902460"},{"product_id":"eg4-flexboss18-hybrid-solar-inverter-18-kw-pv-13-kw-ac-split-phase-3-mppt","title":"EG4 FlexBOSS18 Hybrid Solar Inverter | 18 kW PV \/ 13 kW AC | Split-Phase","description":"\u003cp\u003eThe EG4 FlexBOSS18 is a hybrid solar inverter built for whole-home solar-plus-storage. Per EG4, it utilizes up to 18,000W of solar, delivers 13,000W of continuous split-phase 120\/240V output with PV available (10,000W from battery alone), and supports grid-tied, backup, and off-grid operation from a NEMA 4X outdoor-rated enclosure. It is designed to pair with the EG4 GridBOSS MID for whole-home backup switching, smart loads, and generator integration.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Is For\u003c\/h2\u003e\n\u003cp\u003eHomeowners building solar-plus-storage with room to grow: the FlexBOSS18 parallels up to 16 units per EG4, connects to GridBOSS for 200A whole-home backup, and carries EG4's grid-interactive certifications for utility interconnection where export is desired. If your service runs heavier simultaneous loads or you need more PV, step up to the FlexBOSS21.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e13,000W continuous split-phase output with PV\u003c\/strong\u003e (10,000W battery-only), with surge to 20,000W for 0.5 s per EG4's spec sheet\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUp to 18,000W of utilized PV\u003c\/strong\u003e — per EG4's spec sheet, two MPPTs with five string inputs (3 + 2), 26A rated per MPPT, 600 VDC max input\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48V battery charging\/discharging up to 208A\u003c\/strong\u003e with closed-loop communications for EG4 batteries\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrid-interactive certifications per EG4:\u003c\/strong\u003e UL 1741 SA\/SB with PCS CRD (EG4's product page also lists UL 3141), IEEE 1547, California Rule 21\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGridBOSS-ready:\u003c\/strong\u003e connects to the EG4 GridBOSS MID for whole-home backup, smart load control, AC coupling, and generator management\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNEMA 4X enclosure\u003c\/strong\u003e, -13 to 140 °F operating range, EMP-hardened per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEG4 Connect monitoring\u003c\/strong\u003e via Wi-Fi, Ethernet, or cellular per EG4\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy EG4\u003c\/h2\u003e\n\u003cp\u003eEG4 Electronics is a US-based manufacturer with published spec sheets, manuals, and wiring diagrams for every product and US-based technical support. The FlexBOSS platform is the center of EG4's current residential ecosystem: FlexBOSS inverters, WallMount batteries, and the GridBOSS MID are designed and documented to work as one system with closed-loop communications.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cp\u003eSpecifications below are per EG4's published FlexBOSS18 spec sheet.\u003c\/p\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eContinuous AC output\u003c\/td\u003e\n\u003ctd\u003e13,000W with PV\/grid; 10,000W battery-only\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurge capacity\u003c\/td\u003e\n\u003ctd\u003e20,000W (0.5 s); 15,000W (1 s); 13,500W (1 min)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutput voltage\u003c\/td\u003e\n\u003ctd\u003eSplit-phase 120\/240VAC or 120\/208VAC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePV input\u003c\/td\u003e\n\u003ctd\u003e18,000W max utilized; 2 MPPTs, 5 string inputs (3\/2)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMPPT voltage range\u003c\/td\u003e\n\u003ctd\u003e250–440 VDC full power (120–440 VDC operating; startup 200 VDC; max input 600 VDC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePV current per MPPT\u003c\/td\u003e\n\u003ctd\u003e26A rated \/ 31A short-circuit (Isc)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery voltage\u003c\/td\u003e\n\u003ctd\u003e51.2V nominal (40–60 VDC range)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax charge \/ discharge current\u003c\/td\u003e\n\u003ctd\u003e208A \/ 208A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAC input\u003c\/td\u003e\n\u003ctd\u003e120\/240VAC or 120\/208VAC; 90A pass-through\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransfer time\u003c\/td\u003e\n\u003ctd\u003e20 ms default\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEfficiency\u003c\/td\u003e\n\u003ctd\u003e97% CEC; 97% peak PV-to-grid\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIdle consumption\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;60W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallel capability\u003c\/td\u003e\n\u003ctd\u003eUp to 16 units\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCertifications\u003c\/td\u003e\n\u003ctd\u003eUL 1741 SA\/SB with PCS CRD; California Rule 21; CSA C22.2 107.1 \u0026amp; 330; IEEE 1547:2018 \/ 1547.1:2020 (UL 3141 also listed on EG4's product page)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnclosure \/ environment\u003c\/td\u003e\n\u003ctd\u003eNEMA 4X; -13 to 140 °F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions \/ weight\u003c\/td\u003e\n\u003ctd\u003e30.43 x 22.28 x 11.22 in; 115 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunications \/ monitoring\u003c\/td\u003e\n\u003ctd\u003eWi-Fi, Ethernet, cellular; EG4 Connect app\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e10 years per EG4 (registration required within first year)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eINV031\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eGrid-Tied, Backup, or Off-Grid\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eGrid-tied:\u003c\/strong\u003e solar powers your home and charges batteries, and surplus can be exported where your utility approves the interconnection — export capability and compensation vary by state and utility, and your installer files the application. \u003cstrong\u003eBackup:\u003c\/strong\u003e when the grid fails, the FlexBOSS18 transfers to battery power in 20 ms per EG4; with a GridBOSS at the service entrance, backup extends to the whole 200A service with automatic load management. \u003cstrong\u003eOff-grid:\u003c\/strong\u003e the same hardware runs with no utility at all. The operating mode and any utility-required settings are configured at commissioning.\u003c\/p\u003e\n\n\u003ch2\u003eBattery Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe FlexBOSS18 manages a 48V-class bank with closed-loop communications to EG4 WallMount batteries. The \u003ca href=\"\/products\/eg4-wallmount-314ah-all-weather-battery-48v-16-kwh\"\u003eEG4 WallMount 314Ah all-weather battery (16 kWh)\u003c\/a\u003e is the standard pairing — stack multiple units toward your storage target. Sizing rule of thumb: match storage to daily consumption, not to the inverter rating.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eLicensed-electrician territory: the FlexBOSS18 interconnects with your main panel and — in grid-tied modes — with the utility, which requires an interconnection application before export. Residential energy storage installations are subject to local permitting and inspection. The NEMA 4X enclosure permits outdoor mounting; plan for 115 lb and EG4's published clearances. For whole-home backup rather than a critical-loads panel, install it with the \u003ca href=\"\/products\/eg4-gridboss-200a-mid-microgrid-interconnection-device\"\u003eEG4 GridBOSS 200A MID\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eWarranty \u0026amp; Support\u003c\/h2\u003e\n\u003cp\u003ePer EG4, the FlexBOSS18 carries a 10-year warranty; registration within the first year (or proof of purchase from an authorized distributor) is required. OffGrid Horizon is a family-owned authorized EG4 dealer — call (302) 496-3554 for sizing help, commissioning questions, or warranty support.\u003c\/p\u003e\n\n\u003ch2\u003eShipping\u003c\/h2\u003e\n\u003cp\u003eShips within the contiguous United States. At 115 lb, the FlexBOSS18 ships LTL freight on a pallet. Inspect packaging before signing the delivery receipt and note any damage with the driver; call us right away if anything is wrong.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eFlexBOSS18 or FlexBOSS21?\u003c\/h3\u003e\n\u003cp\u003ePer EG4, the FlexBOSS18 delivers 13 kW with PV (10 kW battery-only) and 18 kW of PV; the \u003ca href=\"\/products\/eg4-flexboss21-hybrid-solar-inverter-21-kw-pv-16-kw-ac-split-phase-4-mppt\"\u003eFlexBOSS21\u003c\/a\u003e delivers 16 kW with PV (12 kW battery-only), 21 kW of PV, and an additional MPPT. Choose by your loads and array size — call us if you are on the fence.\u003c\/p\u003e\n\u003ch3\u003eHow many MPPTs does it have?\u003c\/h3\u003e\n\u003cp\u003ePer EG4's spec sheet: two MPPTs with five total string inputs (three on MPPT 1, two on MPPT 2), 26A rated per MPPT — enough flexibility for arrays split across multiple roof faces.\u003c\/p\u003e\n\u003ch3\u003eCan it sell power back to the grid?\u003c\/h3\u003e\n\u003cp\u003eIt carries EG4's grid-interactive certifications (UL 1741 SA\/SB), but actual export depends on your utility approving your interconnection application. Rules and compensation vary by state and utility.\u003c\/p\u003e\n\u003ch3\u003eDo I need a GridBOSS?\u003c\/h3\u003e\n\u003cp\u003eNot strictly — a FlexBOSS18 can back up a critical-loads panel on its own. The GridBOSS is what turns the system into 200A whole-home backup with automatic switching, smart loads, and generator management.\u003c\/p\u003e\n\u003ch3\u003eDoes it work with a generator?\u003c\/h3\u003e\n\u003cp\u003eGenerator integration in a FlexBOSS system is handled through the GridBOSS, which provides a dedicated 125A generator input per EG4.\u003c\/p\u003e\n\u003ch3\u003eCan I add more inverters later?\u003c\/h3\u003e\n\u003cp\u003eYes — per EG4, up to 16 FlexBOSS18 units can be paralleled.\u003c\/p\u003e\n\u003ch3\u003eIs it OK outdoors?\u003c\/h3\u003e\n\u003cp\u003eYes — the enclosure is NEMA 4X rated with a -13 to 140 °F operating range per EG4.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eBuilding a FlexBOSS system? Call OffGrid Horizon at (302) 496-3554 — we are a family-owned authorized EG4 dealer and will help you spec the inverter, GridBOSS, and batteries as one system.\u003c\/em\u003e\u003c\/p\u003e","brand":"EG4","offers":[{"title":"Default Title","offer_id":49082611794075,"sku":"INV031","price":3369.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/files\/FLEXBOSS18-3.png?v=1784902474"},{"product_id":"eg4-flexboss21-hybrid-solar-inverter-21-kw-pv-16-kw-ac-split-phase-4-mppt","title":"EG4 FlexBOSS21 Hybrid Solar Inverter | 21 kW PV \/ 16 kW AC | Split-Phase","description":"\u003cp\u003eThe EG4 FlexBOSS21 is the higher-output model in EG4's FlexBOSS hybrid inverter line. Per EG4, it utilizes up to 21,000W of solar across three MPPTs, delivers 16,000W of continuous split-phase 120\/240V output with PV available (12,000W from battery alone), and charges a 48V bank at up to 250A — with grid-tied, backup, and off-grid operation from a NEMA 4X outdoor-rated enclosure. It is designed to pair with the EG4 GridBOSS MID for 200A whole-home backup.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Is For\u003c\/h2\u003e\n\u003cp\u003eLarger homes and properties that run heavy simultaneous loads — central air, well pump, range, EV charging — or arrays spanning multiple orientations that need more MPPT capacity and string inputs. If your loads and array are more moderate, the FlexBOSS18 uses the same platform, batteries, and GridBOSS integration.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e16,000W continuous split-phase output with PV\u003c\/strong\u003e (12,000W battery-only), with surge to 24,000W for 0.5 s per EG4's spec sheet\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUp to 21,000W of utilized PV\u003c\/strong\u003e — per EG4's spec sheet, three MPPTs with seven string inputs (3\/2\/2), rated 26A \/ 26A \/ 15A, 600 VDC max input\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48V battery charging\/discharging up to 250A\u003c\/strong\u003e with closed-loop communications for EG4 batteries\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrid-interactive certifications per EG4:\u003c\/strong\u003e UL 1741 SA\/SB with PCS CRD (EG4's product page also lists UL 3141), IEEE 1547, California Rule 21, Hawaii Rule 14H\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGridBOSS-ready:\u003c\/strong\u003e connects to the EG4 GridBOSS MID for whole-home backup, smart loads, AC coupling, and generator management\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNEMA 4X enclosure\u003c\/strong\u003e, -13 to 140 °F operating range, EMP-hardened per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEG4 Connect monitoring\u003c\/strong\u003e via Wi-Fi (dongle included per EG4), Ethernet, or cellular\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy EG4\u003c\/h2\u003e\n\u003cp\u003eEG4 Electronics is a US-based manufacturer with published spec sheets, manuals, and wiring diagrams for every product and US-based technical support. The FlexBOSS platform anchors EG4's current residential ecosystem: FlexBOSS inverters, WallMount batteries, and the GridBOSS MID are engineered and documented to work as one system with closed-loop communications.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cp\u003eSpecifications below are per EG4's published FlexBOSS21 spec sheet.\u003c\/p\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eContinuous AC output\u003c\/td\u003e\n\u003ctd\u003e16,000W (66.7A) with PV and battery; 12,000W (50A) battery-only\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSurge capacity\u003c\/td\u003e\n\u003ctd\u003e24,000W (0.5 s); 18,000W (1 s); 15,000W (6 min)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutput voltage\u003c\/td\u003e\n\u003ctd\u003eSplit-phase 120\/240VAC or 120\/208VAC (L1\/L2\/N)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePV input\u003c\/td\u003e\n\u003ctd\u003e21,000W max utilized; 3 MPPTs, 7 string inputs (3\/2\/2)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMPPT voltage range\u003c\/td\u003e\n\u003ctd\u003e250–440 VDC full power (120–440 VDC operating; startup 200 VDC; max input 600 VDC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePV current per MPPT\u003c\/td\u003e\n\u003ctd\u003e26A \/ 26A \/ 15A rated; 31A \/ 31A \/ 19A Isc\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery voltage\u003c\/td\u003e\n\u003ctd\u003e51.2V nominal (40–60 VDC range)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax charge \/ discharge current\u003c\/td\u003e\n\u003ctd\u003e250A \/ 250A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAC input\u003c\/td\u003e\n\u003ctd\u003eGrid input 50A \/ 12,000W; 90A pass-through\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransfer time\u003c\/td\u003e\n\u003ctd\u003e20 ms default (10 ms configurable)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEfficiency\u003c\/td\u003e\n\u003ctd\u003e97% CEC; 97% peak PV-to-grid; 94% battery-to-load\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIdle consumption\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;65W @ 77 °F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eParallel capability\u003c\/td\u003e\n\u003ctd\u003eUp to 16 units\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCertifications\u003c\/td\u003e\n\u003ctd\u003eUL 1741 SA\/SB with PCS CRD; California Rule 21 Phase I–III; Hawaii Rule 14H; CSA C22.2 107.1 \u0026amp; 330; IEEE 1547:2018 \/ 1547.1:2020 (UL 3141 also listed on EG4's product page)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnclosure \/ environment\u003c\/td\u003e\n\u003ctd\u003eNEMA 4X; -13 to 140 °F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions \/ weight\u003c\/td\u003e\n\u003ctd\u003e30.43 x 22.28 x 11.22 in; 121 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunications \/ monitoring\u003c\/td\u003e\n\u003ctd\u003eWi-Fi (dongle included), Ethernet, cellular; EG4 Connect app\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e10 years per EG4 (registration required within first year)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eINV027\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eGrid-Tied, Backup, or Off-Grid\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eGrid-tied:\u003c\/strong\u003e solar carries the house and charges batteries, and surplus can be exported where your utility approves the interconnection — export capability and compensation vary by state and utility. \u003cstrong\u003eBackup:\u003c\/strong\u003e on grid failure the FlexBOSS21 transfers to battery in 20 ms per EG4 (10 ms configurable); with a GridBOSS at the service entrance, backup covers the full 200A service with automatic smart-load management. \u003cstrong\u003eOff-grid:\u003c\/strong\u003e the same hardware runs without any utility connection. Operating mode and utility-required settings are configured at commissioning.\u003c\/p\u003e\n\n\u003ch2\u003eBattery Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe FlexBOSS21 manages a 48V-class bank with closed-loop communications to EG4 WallMount batteries. With 250A of charge\/discharge current, plan a substantial bank: the \u003ca href=\"\/products\/eg4-wallmount-314ah-indoor-battery-48v-16-kwh-ul9540a-self-heating\"\u003eEG4 WallMount 314Ah indoor battery (16 kWh, UL9540A-tested, self-heating)\u003c\/a\u003e stacks in 16 kWh increments toward the 30+ kWh most 16 kW systems carry.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eLicensed-electrician work: the FlexBOSS21 interconnects with your main panel and, in grid-tied modes, with the utility — an interconnection application is required before export. Residential energy storage is subject to local permitting and inspection. The NEMA 4X enclosure permits outdoor mounting; plan for 121 lb and EG4's published clearances. For whole-home backup at the service entrance, install it with the \u003ca href=\"\/products\/eg4-gridboss-200a-mid-microgrid-interconnection-device\"\u003eEG4 GridBOSS 200A MID\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eWarranty \u0026amp; Support\u003c\/h2\u003e\n\u003cp\u003ePer EG4, the FlexBOSS21 carries a 10-year warranty; registration within the first year (or proof of purchase from an authorized distributor) is required. OffGrid Horizon is a family-owned authorized EG4 dealer — call (302) 496-3554 for sizing, commissioning, or warranty help.\u003c\/p\u003e\n\n\u003ch2\u003eShipping\u003c\/h2\u003e\n\u003cp\u003eShips within the contiguous United States. At 121 lb, the FlexBOSS21 ships LTL freight on a pallet. Inspect packaging before signing the delivery receipt and note any damage with the driver; call us right away if anything looks wrong.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eFlexBOSS21 or FlexBOSS18?\u003c\/h3\u003e\n\u003cp\u003ePer EG4, the FlexBOSS21 delivers 16 kW with PV (12 kW battery-only), 21 kW of PV, and three MPPTs with seven string inputs; the \u003ca href=\"\/products\/eg4-flexboss18-hybrid-solar-inverter-18-kw-pv-13-kw-ac-split-phase-3-mppt\"\u003eFlexBOSS18\u003c\/a\u003e delivers 13 kW with PV and 18 kW of PV on two MPPTs. Choose the 21 for heavier simultaneous loads or a larger, multi-orientation array.\u003c\/p\u003e\n\u003ch3\u003eWhy is output higher with PV than on battery alone?\u003c\/h3\u003e\n\u003cp\u003ePer EG4's spec sheet, the FlexBOSS21 produces 16 kW when solar is contributing and 12 kW from battery alone — size your always-available backup power around the 12 kW battery-only figure.\u003c\/p\u003e\n\u003ch3\u003eCan it sell power back to the grid?\u003c\/h3\u003e\n\u003cp\u003eIt carries EG4's grid-interactive certifications (UL 1741 SA\/SB), but actual export depends on your utility approving your interconnection application. Rules and compensation vary by state and utility.\u003c\/p\u003e\n\u003ch3\u003eDo I need a GridBOSS?\u003c\/h3\u003e\n\u003cp\u003eNot strictly — the FlexBOSS21 can back up a critical-loads panel on its own. The GridBOSS adds 200A whole-home backup switching, four smart-load ports, and a 125A generator input per EG4.\u003c\/p\u003e\n\u003ch3\u003eHow many strings can I land?\u003c\/h3\u003e\n\u003cp\u003ePer EG4's spec sheet: seven string inputs across three MPPTs (3\/2\/2), 600 VDC max input, MPPT ratings of 26A \/ 26A \/ 15A.\u003c\/p\u003e\n\u003ch3\u003eCan I parallel multiple units?\u003c\/h3\u003e\n\u003cp\u003eYes — per EG4, up to 16 units.\u003c\/p\u003e\n\u003ch3\u003eIs it OK outdoors?\u003c\/h3\u003e\n\u003cp\u003eYes — NEMA 4X enclosure with a -13 to 140 °F operating range per EG4.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eSpeccing a whole-home system? Call OffGrid Horizon at (302) 496-3554 — family-owned, authorized EG4 dealer — and we will help you size the FlexBOSS21, GridBOSS, and battery bank together.\u003c\/em\u003e\u003c\/p\u003e","brand":"EG4","offers":[{"title":"Default Title","offer_id":49082612121755,"sku":"INV027","price":3779.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/files\/EG4_FlexBOSS_21_Front.png?v=1784902487"},{"product_id":"eg4-gridboss-200a-mid-microgrid-interconnection-device","title":"EG4 GridBOSS 200A MID | Microgrid Interconnection Device","description":"\u003cp\u003eThe EG4 GridBOSS is a 200A microgrid interconnection device (MID) that sits at the service entrance and manages the connections between the utility grid, your EG4 hybrid inverters, a generator, and your home's loads. Per EG4, it combines a 200A service entrance with a 22kAIC main breaker, whole-home backup switching in roughly 25 ms, a 125A generator input, four smart-load ports, and three hybrid inverter ports — replacing the pile of separate transfer switches, load-shed relays, and generator interlocks a whole-home backup system would otherwise need.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Is For\u003c\/h2\u003e\n\u003cp\u003eAnyone installing an EG4 FlexBOSS18, FlexBOSS21, 18kPV, or 12kPV system who wants the whole house backed up — not just a critical-loads subpanel. It consolidates the service-entrance switching and load management into one engineered, listed device, which generally means cleaner wiring and a simpler inspection than field-built switchgear.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e200A whole-home backup switching\u003c\/strong\u003e — 120\/240VAC service entrance with a 22kAIC main breaker; internal bus rated 350A, software-limited to 200A per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAutomatic transfer in ~25 ms\u003c\/strong\u003e per EG4 when the grid drops, so the house rides through on inverter and battery power\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFour smart-load ports\u003c\/strong\u003e (125A, 80A, 60A, 60A per EG4) that shed lower-priority circuits to stretch battery runtime during an outage\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e125A generator input\u003c\/strong\u003e for standby or portable generators during extended outages\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThree hybrid inverter ports\u003c\/strong\u003e supporting the EG4 12kPV, 18kPV, FlexBOSS18, and FlexBOSS21 per EG4, with AC-coupling support for existing solar per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNEMA 3R outdoor-rated enclosure\u003c\/strong\u003e with a -40 to 113 °F operating range — at 55 lb, light enough for a straightforward service-wall install\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUL 1741, UL 67, UL 869A, and UL 916 listings\u003c\/strong\u003e per EG4's published spec sheet\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy EG4\u003c\/h2\u003e\n\u003cp\u003eEG4 Electronics is a US-based manufacturer with published spec sheets, manuals, and wiring diagrams and US-based technical support. The GridBOSS is purpose-built for EG4's own hybrid inverters, so the switching, load management, and monitoring behave as one documented system in the EG4 Connect platform rather than a mix of third-party components.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cp\u003eSpecifications below are per EG4's published GridBOSS spec sheet.\u003c\/p\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eMicrogrid interconnection device (MID)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eService rating\u003c\/td\u003e\n\u003ctd\u003e200A service entrance; 22kAIC main breaker\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInternal bus\u003c\/td\u003e\n\u003ctd\u003e350A rated, software-limited to 200A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGrid input\u003c\/td\u003e\n\u003ctd\u003e120\/240VAC (L1\/L2\/N), 60 Hz, 200A max\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackup output\u003c\/td\u003e\n\u003ctd\u003e120\/240VAC, 60 Hz, 200A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGenerator input\u003c\/td\u003e\n\u003ctd\u003e120\/240VAC, 60 Hz, 125A max\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSmart-load ports\u003c\/td\u003e\n\u003ctd\u003e4 ports: 125A \/ 80A \/ 60A \/ 60A, with load shedding\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHybrid inverter ports\u003c\/td\u003e\n\u003ctd\u003e3 ports; supports EG4 12kPV, 18kPV, FlexBOSS18, FlexBOSS21\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransfer time\u003c\/td\u003e\n\u003ctd\u003e~25 ms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCertifications\u003c\/td\u003e\n\u003ctd\u003eUL 1741; UL 67; UL 869A; UL 916; CSA C22.2 #29 \u0026amp; #107.1; FCC Part 15 Class B\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnclosure \/ environment\u003c\/td\u003e\n\u003ctd\u003eNEMA 3R; -40 to 113 °F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions \/ weight\u003c\/td\u003e\n\u003ctd\u003e31.5 x 19.7 x 7 in; 55 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunications\u003c\/td\u003e\n\u003ctd\u003eRS485, Wi-Fi, CAN; EG4 Connect monitoring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e10-year standard per EG4 (registration required within first year)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eINV033\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhat a Microgrid Interconnection Device Does\u003c\/h2\u003e\n\u003cp\u003eWhen a grid-tied battery system loses utility power, code requires it to disconnect from the grid before it can keep energizing your home — otherwise it would backfeed the utility's lines. A MID is the device that performs that separation at the service level: it isolates the house from the grid, lets the inverters form their own \"microgrid\" to power the whole 200A service, and re-synchronizes to the utility when power returns. The GridBOSS adds load intelligence on top — shedding its smart-load circuits (for example, HVAC, water heater, or EV charger) in priority order so the battery carries the essentials longer — and brings a 125A generator input into the same enclosure for extended outages. Without a MID, a hybrid inverter can typically back up only a dedicated subpanel; with one, the entire service is switched.\u003c\/p\u003e\n\n\u003ch2\u003eBattery Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe GridBOSS does not connect to batteries directly — storage lives behind the hybrid inverters it manages, such as the \u003ca href=\"\/products\/eg4-flexboss18-hybrid-solar-inverter-18-kw-pv-13-kw-ac-split-phase-3-mppt\"\u003eFlexBOSS18\u003c\/a\u003e or \u003ca href=\"\/products\/eg4-flexboss21-hybrid-solar-inverter-21-kw-pv-16-kw-ac-split-phase-4-mppt\"\u003eFlexBOSS21\u003c\/a\u003e paired with EG4 WallMount 48V batteries in closed-loop communication. The runtime your whole-home backup actually delivers is set by that battery bank, so size it to your daily loads.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eThe GridBOSS installs at the service entrance — this is licensed-electrician work involving the utility service, and it requires local permits and, for grid-interactive systems, utility interconnection approval. The NEMA 3R enclosure is rated for outdoor mounting next to the meter. Plan the smart-load circuits with your electrician up front: which circuits shed first is a design decision, not an afterthought.\u003c\/p\u003e\n\n\u003ch2\u003eWarranty \u0026amp; Support\u003c\/h2\u003e\n\u003cp\u003ePer EG4, the GridBOSS carries a 10-year standard warranty; registration within the first year (or proof of purchase from an authorized distributor) is required. OffGrid Horizon is a family-owned authorized EG4 dealer — call (302) 496-3554 and we will help with system design questions or warranty claims.\u003c\/p\u003e\n\n\u003ch2\u003eShipping\u003c\/h2\u003e\n\u003cp\u003eShips within the contiguous United States. At 55 lb, the GridBOSS typically ships by ground carrier or palletized with an inverter order. Inspect the carton on arrival and note any damage with the carrier before signing; contact us immediately if anything is wrong.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eDo I need a GridBOSS for a FlexBOSS system?\u003c\/h3\u003e\n\u003cp\u003eNot strictly — a FlexBOSS inverter can back up a critical-loads panel on its own. The GridBOSS is what upgrades the system to automatic whole-home backup at the 200A service level, with smart-load shedding and generator integration.\u003c\/p\u003e\n\u003ch3\u003eWhich inverters does it work with?\u003c\/h3\u003e\n\u003cp\u003ePer EG4, the hybrid ports support the EG4 12kPV, \u003ca href=\"\/products\/eg4-18kpv-all-in-one-hybrid-solar-inverter-18-kw-pv-12-kw-ac-split-phase\"\u003e18kPV\u003c\/a\u003e, FlexBOSS18, and FlexBOSS21 — up to three inverter connections.\u003c\/p\u003e\n\u003ch3\u003eDoes it work with a generator?\u003c\/h3\u003e\n\u003cp\u003eYes — a dedicated 125A generator input is built in per EG4, so a standby or portable generator can support the system during extended outages.\u003c\/p\u003e\n\u003ch3\u003eWhat are the smart-load ports for?\u003c\/h3\u003e\n\u003cp\u003eFour ports (125A, 80A, 60A, 60A per EG4) for circuits you are willing to shed during an outage — the GridBOSS drops them in priority order to keep essential loads running longer on battery.\u003c\/p\u003e\n\u003ch3\u003eCan it AC-couple my existing solar?\u003c\/h3\u003e\n\u003cp\u003ePer EG4, the GridBOSS supports AC coupling, letting an existing grid-tie array feed the system. Configuration depends on your equipment — call us to confirm your setup.\u003c\/p\u003e\n\u003ch3\u003eDoes it include batteries or an inverter?\u003c\/h3\u003e\n\u003cp\u003eNo — the GridBOSS is the interconnection and switching device. Pair it with one to three EG4 hybrid inverters and a 48V battery bank.\u003c\/p\u003e\n\u003ch3\u003eIs utility approval required?\u003c\/h3\u003e\n\u003cp\u003eYes, for grid-interactive systems — the GridBOSS sits at the service entrance, so installation involves local permitting and your utility's interconnection process. Export of solar power remains subject to utility approval.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eDesigning whole-home backup? Call OffGrid Horizon at (302) 496-3554 — family-owned, authorized EG4 dealer — and we will map out the GridBOSS, inverters, and batteries for your service.\u003c\/em\u003e\u003c\/p\u003e","brand":"EG4","offers":[{"title":"Default Title","offer_id":49082615824539,"sku":"INV033","price":1999.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/files\/EG4_GridBOSS_Front.png?v=1784902581"},{"product_id":"eg4-wallmount-280ah-all-weather-battery-48v-14-3-kwh-ul1973","title":"EG4 WallMount 280Ah All-Weather Battery | 48V | 14.3 kWh | UL1973","description":"\u003cp\u003eThe EG4 WallMount 280Ah All-Weather is a 48V-class (51.2V nominal) LiFePO4 battery that puts 14.3 kWh of home energy storage on the wall instead of the floor. Its IP65-rated enclosure is built for indoor or outdoor installation, it carries a UL1973 certification, and it communicates in closed-loop with EG4 and other compatible 48V inverters. OffGrid Horizon is a family-owned authorized EG4 dealer, and every unit ships with full manufacturer warranty support.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Is For\u003c\/h2\u003e\n\u003cp\u003eThis battery fits homeowners adding storage to a 48V inverter system where the practical mounting spot is an exterior wall, a garage, or a utility space. Because the enclosure is weather-rated, the battery can be installed beside an outdoor-mounted inverter without building a dedicated battery room. It also suits owners of non-EG4 systems: per EG4, the BMS supports closed-loop communication with EG4, Schneider, Sol-Ark, Victron, Growatt, Luxpower, and Deye inverters over RS485\/CAN.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e14.3 kWh from a single wall-mounted unit\u003c\/strong\u003e — 280Ah at 51.2V nominal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIP65 all-weather enclosure\u003c\/strong\u003e rated for indoor or outdoor installation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUL1973 certified, with UL9540A fire-safety test data\u003c\/strong\u003e — EG4 lists this model as \"UL1973, UL9540A (Passed)\"\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOver 8,000 cycles at 80% depth of discharge\u003c\/strong\u003e per EG4, for up to 82.6 MWh of lifetime energy throughput\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e140A continuous charge and discharge\u003c\/strong\u003e, with 200A discharge supported for 30 minutes per EG4's spec sheet\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntegrated self-heating\u003c\/strong\u003e — a 224W internal heater activates at or below 32°F so the pack can accept charge in cold weather\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLCD touchscreen\u003c\/strong\u003e for on-battery status monitoring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClosed-loop RS485\/CAN communication\u003c\/strong\u003e with EG4 and other compatible inverters\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy EG4\u003c\/h2\u003e\n\u003cp\u003eEG4 Electronics is a Texas-based manufacturer that publishes full spec sheets, test data, and installation manuals for its equipment and backs this battery with a 10-year warranty. Its inverters and batteries are designed to work as one system, so state-of-charge reporting and charge control stay coordinated without third-party configuration work.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal voltage\u003c\/td\u003e\n\u003ctd\u003e51.2V (48V class)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCapacity\u003c\/td\u003e\n\u003ctd\u003e280Ah \/ 14.3 kWh\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChemistry\u003c\/td\u003e\n\u003ctd\u003eLiFePO4 (lithium iron phosphate)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCycle life\u003c\/td\u003e\n\u003ctd\u003eOver 8,000 cycles at 80% DoD, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax continuous charge\u003c\/td\u003e\n\u003ctd\u003e140A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax continuous discharge\u003c\/td\u003e\n\u003ctd\u003e140A (200A for 30 minutes, per EG4)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnclosure rating\u003c\/td\u003e\n\u003ctd\u003eIP65 — indoor or outdoor installation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCharge temperature\u003c\/td\u003e\n\u003ctd\u003e32°F to 122°F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDischarge temperature\u003c\/td\u003e\n\u003ctd\u003e-4°F to 131°F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSelf-heating\u003c\/td\u003e\n\u003ctd\u003e224W internal heater, activates at or below 32°F per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e36.1 x 22.3 x 9.1 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e308.6 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication\u003c\/td\u003e\n\u003ctd\u003eRS485 \/ CAN, closed-loop with compatible inverters\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCertifications\u003c\/td\u003e\n\u003ctd\u003eUL1973; UL9540A (Passed), per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e10 years, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eFEWPP-48143-G1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eAll-Weather vs Indoor — Which WallMount?\u003c\/h2\u003e\n\u003cp\u003eEG4's WallMount line includes three residential models. This 280Ah All-Weather unit delivers 14.3 kWh in an IP65 enclosure. The newer \u003ca href=\"\/products\/eg4-wallmount-314ah-all-weather-battery-48v-16-kwh\"\u003eWallMount 314Ah All-Weather\u003c\/a\u003e steps up to 16 kWh with an IP67 enclosure and a 10,000-cycle rating per EG4. The \u003ca href=\"\/products\/eg4-wallmount-314ah-indoor-battery-48v-16-kwh-ul9540a-self-heating\"\u003eWallMount 314Ah Indoor\u003c\/a\u003e offers the same 16 kWh in a lighter IP20 enclosure for garages, basements, and utility rooms. All three include self-heating for cold-weather charging. If your project needs outdoor mounting, choose an All-Weather model; if the battery will live indoors and you want the lightest unit, the Indoor model is the practical pick.\u003c\/p\u003e\n\n\u003ch2\u003eInverter Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe battery communicates in closed-loop over RS485\/CAN with EG4 inverters, including the \u003ca href=\"\/products\/eg4-flexboss18-hybrid-solar-inverter-18-kw-pv-13-kw-ac-split-phase-3-mppt\"\u003eEG4 FlexBOSS18 hybrid inverter\u003c\/a\u003e, so the inverter reads real state-of-charge directly from the BMS. Per EG4, closed-loop profiles are also available for Schneider, Sol-Ark, Victron, Growatt, Luxpower, and Deye inverters. Call us to confirm the correct protocol setting for your inverter before ordering.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eInstallation should be performed by a licensed electrician, and residential energy storage is subject to local permitting and inspection. At 308.6 lb, this battery requires mechanical lifting equipment or several people to position, and it must be anchored to structural framing capable of carrying the load. Follow the EG4 installation manual for mounting hardware, torque values, and required clearances, and site outdoor units out of direct afternoon sun where practical.\u003c\/p\u003e\n\n\u003ch2\u003eWarranty \u0026amp; Support\u003c\/h2\u003e\n\u003cp\u003eEG4 backs the WallMount 280Ah All-Weather with a 10-year manufacturer warranty. Register the battery with EG4 after purchase and keep your OffGrid Horizon invoice — as an authorized dealer, our sales records document your coverage. If you ever need warranty service, call us at (302) 496-3554 and we will help you work through EG4's process.\u003c\/p\u003e\n\n\u003ch2\u003eShipping\u003c\/h2\u003e\n\u003cp\u003eThis battery ships by LTL freight on a pallet within the United States. Delivery is curbside with a liftgate. Please inspect the packaging and unit before signing the delivery receipt, and note any damage with the driver — this preserves your ability to file a freight claim.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eCan this battery be mounted outdoors?\u003c\/h3\u003e\n\u003cp\u003eYes. The IP65-rated enclosure is designed for indoor or outdoor installation. Keep it within EG4's published operating temperature ranges and out of standing water or direct spray where possible.\u003c\/p\u003e\n\u003ch3\u003eWill it charge in freezing weather?\u003c\/h3\u003e\n\u003cp\u003eThe cells themselves charge from 32°F to 122°F, but the built-in 224W heater activates at or below 32°F per EG4, warming the pack so charging can resume in cold conditions. Discharge is supported from -4°F to 131°F.\u003c\/p\u003e\n\u003ch3\u003eCan I parallel multiple units?\u003c\/h3\u003e\n\u003cp\u003eYes — the battery is designed to parallel with additional WallMount units to grow a bank. EG4 does not publish a maximum parallel count on this model's spec sheet, so call us to confirm the supported bank size for your inverter setup.\u003c\/p\u003e\n\u003ch3\u003eWhich inverters work in closed-loop?\u003c\/h3\u003e\n\u003cp\u003eEG4 inverters such as the FlexBOSS series, plus Schneider, Sol-Ark, Victron, Growatt, Luxpower, and Deye models per EG4's published compatibility list.\u003c\/p\u003e\n\u003ch3\u003eWhat does the UL9540A reference mean?\u003c\/h3\u003e\n\u003cp\u003eUL9540A is a fire-safety test method, not a product listing. Per EG4, this battery has passed UL9540A testing, and it carries a UL1973 certification. Your local building department can confirm which documentation applies to your permit.\u003c\/p\u003e\n\u003ch3\u003eHow long will it run my house?\u003c\/h3\u003e\n\u003cp\u003e14.3 kWh covers roughly half a day to a full day of essential loads (refrigeration, lighting, communications, a well pump used sparingly) for a typical US household. For whole-home or multi-day coverage, parallel additional units.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eNot sure whether the 280Ah or 314Ah WallMount fits your system? Call OffGrid Horizon at (302) 496-3554 — we are a family-owned authorized EG4 dealer and will help you size the bank before you order.\u003c\/em\u003e\u003c\/p\u003e","brand":"EG4","offers":[{"title":"Default Title","offer_id":49082616184987,"sku":"FEWPP-48143-G1","price":3519.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/files\/EG4-PowerPro-front.png?v=1784902593"},{"product_id":"eg4-wallmount-314ah-all-weather-battery-48v-16-kwh","title":"EG4 WallMount 314Ah All-Weather Battery | 48V | 16 kWh","description":"\u003cp\u003eThe EG4 WallMount 314Ah All-Weather is a 48V-class (51.2V nominal) LiFePO4 battery delivering 16 kWh of nominal storage from a single IP67-rated, wall-mounted unit built for indoor or outdoor installation. Per EG4 it is rated for 10,000 cycles at 80% depth of discharge, carries UL1973 certification with UL9540A test data, and communicates in closed-loop with EG4 inverters. OffGrid Horizon is a family-owned authorized EG4 dealer, and every unit ships with full manufacturer warranty support.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Is For\u003c\/h2\u003e\n\u003cp\u003eThis is the battery for homeowners building or expanding an EG4 FlexBOSS-based system where the batteries will mount outdoors or in an unconditioned space. The IP67 enclosure means no dedicated battery room is required — the unit can live on an exterior wall beside the inverter. It is the same battery included in our FlexBOSS18 and FlexBOSS21 All-Weather kits, so single units are the natural way to expand one of those systems later.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e16 kWh nominal from one unit\u003c\/strong\u003e — 314Ah at 51.2V; EG4 lists 12.86 kWh usable at 80% depth of discharge\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIP67 weather-resistant enclosure\u003c\/strong\u003e for indoor or outdoor mounting\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e10,000 cycles at 80% DoD\u003c\/strong\u003e per EG4 (rated at 0.5C, 77°F)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e157A max continuous charge \/ 200A max continuous discharge\u003c\/strong\u003e, with 12.8 kW 3-second peak per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUL1973 certified with UL9540A fire-safety test data\u003c\/strong\u003e per EG4's spec sheet; contact EG4 or call us regarding UL9540 system configurations\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntegrated internal heater\u003c\/strong\u003e — 448W, activates at or below 32°F per EG4, so cold weather does not stop charging\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThird-generation BMS\u003c\/strong\u003e with active cell balancing, Bluetooth and Wi-Fi monitoring through the EG4 Connect app, and Auto-ID addressing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eParallels up to 32 units\u003c\/strong\u003e per EG4 for large-capacity banks\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy EG4\u003c\/h2\u003e\n\u003cp\u003eEG4 Electronics is a Texas-based manufacturer that publishes complete spec sheets, manuals, and fire-safety test data, and backs this battery for 10 years or 10,000 cycles. Batteries and inverters from one manufacturer communicate natively, which keeps state-of-charge accurate and charge control coordinated without third-party tuning.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eWM48314AW\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal voltage\u003c\/td\u003e\n\u003ctd\u003e51.2V (48V class)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCapacity\u003c\/td\u003e\n\u003ctd\u003e314Ah \/ 16 kWh nominal (12.86 kWh usable at 80% DoD, per EG4)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChemistry\u003c\/td\u003e\n\u003ctd\u003eLiFePO4 (lithium iron phosphate)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCycle life\u003c\/td\u003e\n\u003ctd\u003e10,000 cycles at 0.5C, 77°F, 80% DoD, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax continuous charge\u003c\/td\u003e\n\u003ctd\u003e157A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax continuous discharge\u003c\/td\u003e\n\u003ctd\u003e200A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak power\u003c\/td\u003e\n\u003ctd\u003e12.8 kW for 3 seconds, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnclosure rating\u003c\/td\u003e\n\u003ctd\u003eIP67 — indoor or outdoor installation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCharge temperature\u003c\/td\u003e\n\u003ctd\u003e32°F to 122°F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDischarge temperature\u003c\/td\u003e\n\u003ctd\u003e-4°F to 131°F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSelf-heating\u003c\/td\u003e\n\u003ctd\u003e448W internal heater; on at 32°F or below, off at 37°F, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e34.6 x 21.7 x 9.3 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e309 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax units in parallel\u003c\/td\u003e\n\u003ctd\u003e32, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication\u003c\/td\u003e\n\u003ctd\u003eRS485 \/ CAN closed-loop; Bluetooth and Wi-Fi via EG4 Connect app\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCertifications\u003c\/td\u003e\n\u003ctd\u003eUL1973; UL9540A, per EG4 (UL9540 in supported configurations — see EG4)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e10 years or 10,000 cycles, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eFEWAW-48161-G1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eAll-Weather vs Indoor — Which WallMount?\u003c\/h2\u003e\n\u003cp\u003eChoose this All-Weather model when the battery must mount outside or in a space exposed to weather — the IP67 enclosure is the difference you are paying for. If the battery will live in a garage, basement, or utility room, the \u003ca href=\"\/products\/eg4-wallmount-314ah-indoor-battery-48v-16-kwh-ul9540a-self-heating\"\u003eWallMount 314Ah Indoor\u003c\/a\u003e delivers the same 16 kWh and the same 10,000-cycle rating in a lighter IP20 enclosure, and per EG4 it forms a UL9540-listed system with FlexBOSS inverters. The earlier \u003ca href=\"\/products\/eg4-wallmount-280ah-all-weather-battery-48v-14-3-kwh-ul1973\"\u003eWallMount 280Ah All-Weather\u003c\/a\u003e remains available at 14.3 kWh for systems standardized on that model. All three include self-heating.\u003c\/p\u003e\n\n\u003ch2\u003eInverter Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe WallMount 314Ah All-Weather communicates in closed-loop over RS485\/CAN with EG4 inverters — the pairing EG4 designed it around is the FlexBOSS series, including the \u003ca href=\"\/products\/eg4-flexboss21-hybrid-solar-inverter-21-kw-pv-16-kw-ac-split-phase-4-mppt\"\u003eEG4 FlexBOSS21 hybrid inverter\u003c\/a\u003e. Auto-ID addressing assigns battery IDs automatically when multiple units are paralleled. Using a non-EG4 48V inverter? Call us to confirm protocol compatibility before ordering.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eInstallation should be performed by a licensed electrician, and residential energy storage is subject to local permitting and inspection. The unit weighs 309 lb and supports floor-mount or wall-attached installation per EG4 — wall mounting requires anchoring into structural framing rated for the load, and positioning requires lifting equipment or several people. Follow the EG4 installation manual for hardware, torque values, and clearances, and keep outdoor units out of direct afternoon sun where practical.\u003c\/p\u003e\n\n\u003ch2\u003eWarranty \u0026amp; Support\u003c\/h2\u003e\n\u003cp\u003eEG4 warrants this battery for 10 years or 10,000 cycles, whichever comes first. Register the battery with EG4 after purchase and keep your OffGrid Horizon invoice — as an authorized dealer, our sales records document your coverage. Need help with a claim or a firmware question? Call us at (302) 496-3554.\u003c\/p\u003e\n\n\u003ch2\u003eShipping\u003c\/h2\u003e\n\u003cp\u003eThis battery ships by LTL freight on a pallet within the United States. Delivery is curbside with a liftgate. Inspect the packaging and unit before signing the delivery receipt and note any damage with the driver — this preserves your ability to file a freight claim.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eWhat is the difference between 16 kWh nominal and usable capacity?\u003c\/h3\u003e\n\u003cp\u003eEG4 rates the pack at 16 kWh nominal and lists 12.86 kWh usable at 80% depth of discharge — the operating window that supports the 10,000-cycle rating. Deeper discharge is possible; cycling shallower extends pack life.\u003c\/p\u003e\n\u003ch3\u003eCan it really live outdoors year-round?\u003c\/h3\u003e\n\u003cp\u003eYes — the enclosure is IP67 rated and the internal heater keeps charging available down to EG4's published limits. Discharge is supported from -4°F to 131°F.\u003c\/p\u003e\n\u003ch3\u003eHow many can I parallel?\u003c\/h3\u003e\n\u003cp\u003eUp to 32 units per EG4's spec sheet. Auto-ID addressing configures battery IDs automatically as you add units.\u003c\/p\u003e\n\u003ch3\u003eDoes it work with the FlexBOSS18 as well as the FlexBOSS21?\u003c\/h3\u003e\n\u003cp\u003eYes — both FlexBOSS inverters run closed-loop with this battery. We also sell it pre-paired in FlexBOSS18 and FlexBOSS21 All-Weather kits.\u003c\/p\u003e\n\u003ch3\u003eIs this battery UL9540 listed?\u003c\/h3\u003e\n\u003cp\u003eUL9540A is a fire-safety test method, and per EG4 this model carries UL1973 certification with UL9540A test data. For UL9540 energy-storage-system configurations, EG4 directs buyers to its published list of supported inverter pairings — call us and we will confirm what your permit office needs.\u003c\/p\u003e\n\u003ch3\u003eHow much power can one battery deliver?\u003c\/h3\u003e\n\u003cp\u003e200A continuous discharge — roughly 10.2 kW at nominal voltage — with a 12.8 kW 3-second peak per EG4. Parallel batteries to support larger inverter loads.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003ePlanning a bank or matching a battery to your inverter? Call OffGrid Horizon at (302) 496-3554 — we are a family-owned authorized EG4 dealer and will help you get the configuration right.\u003c\/em\u003e\u003c\/p\u003e","brand":"EG4","offers":[{"title":"Default Title","offer_id":49082616414363,"sku":"FEWAW-48161-G1","price":4144.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/files\/2-scaled_9e7a9ef0-2858-4b4f-8f12-aba7eb21d02f.png?v=1784902609"},{"product_id":"eg4-wallmount-314ah-indoor-battery-48v-16-kwh-ul9540a-self-heating","title":"EG4 WallMount 314Ah Indoor Battery | 48V | 16 kWh | UL9540A | Self-Heating","description":"\u003cp\u003eThe EG4 WallMount 314Ah Indoor is a 48V-class (51.2V nominal) LiFePO4 battery delivering 16 kWh of nominal storage in a wall- or floor-mounted unit built for garages, basements, and utility rooms. Per EG4 it is certified to UL1973 with UL9540A fire-safety test data, forms a UL9540 system with the FlexBOSS21 and FlexBOSS18 inverters, and includes self-heating so unheated spaces keep charging through winter. OffGrid Horizon is a family-owned authorized EG4 dealer, and every unit ships with full manufacturer warranty support.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Is For\u003c\/h2\u003e\n\u003cp\u003eThis is the battery for homeowners installing storage indoors — especially in cold climates, where the internal heater keeps charging available in unconditioned garages, and in jurisdictions where UL9540A test documentation and a UL9540 system pairing smooth the permitting conversation. At 293.2 lb it is the lightest 16 kWh unit in the WallMount line, and it is the same battery included in our FlexBOSS18 and FlexBOSS21 Indoor kits.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e16 kWh nominal from one unit\u003c\/strong\u003e — 314Ah at 51.2V; EG4 lists 12.86 kWh usable at 80% depth of discharge\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUL1973 | UL9540A | UL9540 with FlexBOSS21 and FlexBOSS18\u003c\/strong\u003e — certifications exactly as EG4 publishes them\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSelf-heating cells\u003c\/strong\u003e — a 448W internal heater activates at or below 32°F per EG4, so a freezing garage does not take charging offline\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e10,000+ cycles at 80% DoD\u003c\/strong\u003e per EG4, for up to 115.7 MWh of lifetime energy throughput\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e157A max continuous charge \/ 200A max continuous discharge\u003c\/strong\u003e, with 12.8 kW 3-second peak per EG4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHybrid wall or floor mount design\u003c\/strong\u003e keeps garage floor space usable\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBMS with Wi-Fi monitoring\u003c\/strong\u003e through the EG4 Connect app and RS485\/CAN closed-loop communication\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eParallels up to 32 units\u003c\/strong\u003e per EG4 for large-capacity banks\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy EG4\u003c\/h2\u003e\n\u003cp\u003eEG4 Electronics is a Texas-based manufacturer that publishes complete spec sheets, manuals, and fire-safety test data, and backs this battery for 10 years or 10,000 cycles. Because EG4 builds both the batteries and the FlexBOSS inverters, the closed-loop pairing is engineered and documented by one company — including the UL9540 system configuration many building departments ask about.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eWM48314IN\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal voltage\u003c\/td\u003e\n\u003ctd\u003e51.2V (48V class)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCapacity\u003c\/td\u003e\n\u003ctd\u003e314Ah \/ 16 kWh nominal (12.86 kWh usable at 80% DoD, per EG4)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChemistry\u003c\/td\u003e\n\u003ctd\u003eLiFePO4 (lithium iron phosphate)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCycle life\u003c\/td\u003e\n\u003ctd\u003e10,000 cycles at 0.5C, 77°F, 80% DoD, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax continuous charge\u003c\/td\u003e\n\u003ctd\u003e157A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax continuous discharge\u003c\/td\u003e\n\u003ctd\u003e200A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePeak power\u003c\/td\u003e\n\u003ctd\u003e12.8 kW for 3 seconds, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnclosure rating\u003c\/td\u003e\n\u003ctd\u003eIP20 — indoor installation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCharge temperature\u003c\/td\u003e\n\u003ctd\u003e32°F to 122°F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDischarge temperature\u003c\/td\u003e\n\u003ctd\u003e-4°F to 131°F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSelf-heating\u003c\/td\u003e\n\u003ctd\u003e448W internal heater; on at 32°F or below, off at 37°F, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e34.1 x 18.1 x 9.6 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e293.2 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eWall-attached or floor mount, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax units in parallel\u003c\/td\u003e\n\u003ctd\u003e32, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication\u003c\/td\u003e\n\u003ctd\u003eRS485 \/ CAN closed-loop; Wi-Fi via EG4 Connect app\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCertifications\u003c\/td\u003e\n\u003ctd\u003eUL1973; UL9540A; UL9540 with FlexBOSS21 and FlexBOSS18, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e10 years or 10,000 cycles, per EG4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eFEWMT-48161-G1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eAll-Weather vs Indoor — Which WallMount?\u003c\/h2\u003e\n\u003cp\u003eChoose this Indoor model when the battery will live in a garage, basement, or utility room: you get the same 16 kWh and 10,000-cycle rating as the All-Weather version in a lighter enclosure, plus EG4's published UL9540 system pairing with FlexBOSS inverters. If the battery must mount outside or in a weather-exposed location, choose the IP67-rated \u003ca href=\"\/products\/eg4-wallmount-314ah-all-weather-battery-48v-16-kwh\"\u003eWallMount 314Ah All-Weather\u003c\/a\u003e instead. Both models are self-heating — the Indoor unit's heater matters in unheated garages, not just outdoors.\u003c\/p\u003e\n\n\u003ch2\u003eInverter Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe WallMount 314Ah Indoor runs closed-loop over RS485\/CAN with EG4 inverters, and per EG4 it forms a UL9540 system configuration with the \u003ca href=\"\/products\/eg4-flexboss21-hybrid-solar-inverter-21-kw-pv-16-kw-ac-split-phase-4-mppt\"\u003eEG4 FlexBOSS21\u003c\/a\u003e and \u003ca href=\"\/products\/eg4-flexboss18-hybrid-solar-inverter-18-kw-pv-13-kw-ac-split-phase-3-mppt\"\u003eEG4 FlexBOSS18\u003c\/a\u003e hybrid inverters. Closed-loop keeps the inverter's state-of-charge reading accurate and charge parameters coordinated. Running a different 48V inverter? Call us to confirm protocol support before ordering.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation\u003c\/h2\u003e\n\u003cp\u003eInstallation should be performed by a licensed electrician, and residential energy storage is subject to local permitting and inspection. The unit weighs 293.2 lb and supports wall-attached or floor-mount installation per EG4 — wall mounting requires anchoring into structural framing rated for the load, and positioning takes lifting equipment or several people. Follow the EG4 installation manual for mounting hardware, torque values, and clearances, and confirm placement rules for energy storage with your local building department.\u003c\/p\u003e\n\n\u003ch2\u003eWarranty \u0026amp; Support\u003c\/h2\u003e\n\u003cp\u003eEG4 warrants this battery for 10 years or 10,000 cycles, whichever comes first. Register the battery with EG4 after purchase and keep your OffGrid Horizon invoice — as an authorized dealer, our sales records document your coverage. Need help with a claim or a firmware question? Call us at (302) 496-3554.\u003c\/p\u003e\n\n\u003ch2\u003eShipping\u003c\/h2\u003e\n\u003cp\u003eThis battery ships by LTL freight on a pallet within the United States. Delivery is curbside with a liftgate. Inspect the packaging and unit before signing the delivery receipt and note any damage with the driver — this preserves your ability to file a freight claim.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eWhy does self-heating matter for an indoor battery?\u003c\/h3\u003e\n\u003cp\u003eLiFePO4 cells cannot accept charge below 32°F. Many \"indoor\" locations — detached garages, unheated basements, outbuildings — drop below freezing in winter. Per EG4, this pack's 448W heater switches on at 32°F and off at 37°F, keeping solar and grid charging available without an external heat source.\u003c\/p\u003e\n\u003ch3\u003eWhat does \"UL9540 with FlexBOSS21 and FlexBOSS18\" mean?\u003c\/h3\u003e\n\u003cp\u003eUL9540A is a fire-safety test method and UL1973 is the battery certification; UL9540 covers the complete energy storage system. Per EG4, this battery achieves the UL9540 system designation when paired with the FlexBOSS21 or FlexBOSS18 — useful documentation for permitting.\u003c\/p\u003e\n\u003ch3\u003eCan it be installed outdoors?\u003c\/h3\u003e\n\u003cp\u003eNo — the enclosure is IP20 rated for indoor spaces. For outdoor mounting, use the WallMount 314Ah All-Weather.\u003c\/p\u003e\n\u003ch3\u003eHow many can I parallel?\u003c\/h3\u003e\n\u003cp\u003eUp to 32 units per EG4's spec sheet, with capacity growing 16 kWh per battery.\u003c\/p\u003e\n\u003ch3\u003eHow much power can one battery deliver?\u003c\/h3\u003e\n\u003cp\u003e200A continuous discharge — roughly 10.2 kW at nominal voltage — with a 12.8 kW 3-second peak per EG4. Parallel batteries to support larger loads.\u003c\/p\u003e\n\u003ch3\u003eDoes it come as part of a complete system?\u003c\/h3\u003e\n\u003cp\u003eYes — we offer this battery pre-paired with the FlexBOSS18 or FlexBOSS21 in our Indoor kits, configurable from 16 to 48 kWh.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eQuestions about permitting documentation or bank sizing? Call OffGrid Horizon at (302) 496-3554 — we are a family-owned authorized EG4 dealer and talk through these details every day.\u003c\/em\u003e\u003c\/p\u003e","brand":"EG4","offers":[{"title":"Default Title","offer_id":49082618970267,"sku":"FEWMT-48161-G1","price":3784.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/files\/BigBattery-ALL-PRODUCT-IMAGES-1.png?v=1784902638"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0746\/0614\/9787\/collections\/EG4-Logo-1.webp?v=1784752691","url":"https:\/\/offgridhorizon.com\/collections\/eg4.oembed?page=2","provider":"OffGrid Horizon","version":"1.0","type":"link"}