BigBattery NEXUS 15 kWh 48V LiFePO4 battery paired with EG4 6000XP all-in-one inverter

Product Description

This kit pairs one BigBattery NEXUS 48V LiFePO4 battery — 280Ah, 14.3 kWh usable per BigBattery — with the EG4 6000XP all-in-one off-grid inverter: 6,000W of continuous split-phase 120/240V output with dual MPPTs accepting up to 8,000W of PV, per EG4. It is an off-grid system: per BigBattery, the pairing is sold for home backup and full off-grid operation, and per BigBattery the NEXUS is compatible with all EG4 inverters over its RS485 / RJ45 / CAN communications.

Who This Is For

Cabins, tiny homes, small off-grid households, and essential-circuit backup — refrigeration, lights, electronics, a water pump, and a moderate 240V load. It suits owners who want EG4's widely installed XP-series inverter platform on a large single-cabinet battery. If you run central air, a well pump plus large appliances simultaneously, or a full-size home, step up to the EG4 12000XP V2 version of this kit.

Key Features

  • 6,000W continuous split-phase 120/240V output, per EG4; surge rated 12,000W (3.5 seconds), per BigBattery's kit listing
  • Up to 8,000W of PV input — 4,000W per MPPT across dual MPPTs, with high 480Vdc input, per EG4
  • UL 1741 Certified transformerless design with idle consumption as low as 30W with PV, per EG4
  • Parallels up to 16 inverters for up to 96 kW combined output, per EG4
  • NEXUS battery: 280Ah, 14.3 kWh usable, 6,000+ cycle life, self-heating function, aerosol fire suppression, per BigBattery
  • Battery parallels up to 15 units (up to 214.5 kWh), per BigBattery

Why BigBattery

BigBattery is a US company building LiFePO4 energy storage for off-grid and home backup use. NEXUS batteries ship from Texas, carry a 12-Year Limited Warranty, and are backed by lifetime USA-based technical support, per BigBattery — here matched with EG4's popular 6000XP inverter. Browse our EG4 collection for the rest of the line.

What's In the Kit

Solar panels, racking, and array wiring are not included. BigBattery's kit listing does not itemize cables or accessories, so call us at (302) 496-3554 before ordering and we'll confirm exactly what ships with your configuration.

Specifications

Battery 1 × BigBattery NEXUS, 48V class (51.2V nominal), LiFePO4, 280Ah
Usable energy 14.3 kWh, per BigBattery
Battery max continuous discharge 140A (7.6 kW max continuous power), per BigBattery
Battery cycle life 6,000+ cycles, per BigBattery
Battery communications RS485 / RJ45 / CAN; compatible with all EG4 inverters, per BigBattery
Battery dimensions / weight 19.7 × 27.5 × 15.7 in; approx. 315 lb
Inverter EG4 6000XP — 6,000W continuous, split-phase 120/240V, per EG4
Surge 12,000W (3.5 s), per BigBattery's kit listing
Solar input Up to 8,000W (4,000W per MPPT), dual MPPTs, high 480Vdc input, per EG4
Inverter parallel capability Up to 16 units (96 kW combined), per EG4
Inverter certifications UL 1741 Certified, per EG4
Battery warranty 12-Year Limited Warranty, per BigBattery
Inverter warranty 5-year full parts replacement or full product replacement warranty, per EG4 (registration or authorized-distributor proof of purchase required — see below)
Kit SKU K0152

Sizing Your Off-Grid Home

Start with energy. Example assumptions — adjust for your own loads: refrigerator 1.5 kWh/day, chest freezer 1.0, LED lighting 0.4, well pump 1.0, electronics and internet 1.0, washer 0.5. That is about 5.4 kWh/day, so 14.3 kWh usable (per BigBattery) covers roughly two such days without sun. A mini-split adds roughly 5–15 kWh/day in season depending on size and climate — if that is in your plan, look at the 30–45 kWh version of this kit.

Then power: 6,000W continuous covers most small-household essential panels, and one NEXUS supports up to 140A — about 7.6 kW — of continuous discharge per BigBattery, so the battery carries this inverter at full rated output. On the solar side, 8,000W of PV (per EG4) in reasonable US sun can put well over 20 kWh/day back into a 14.3 kWh bank — recharge is rarely the bottleneck at this scale.

Installation

Setting the 315 lb battery cabinet and wall-mounting the inverter are the straightforward parts. The AC side — panel interconnection, overcurrent protection, grounding, bonding — belongs to a licensed electrician working to the National Electrical Code (NEC) and local codes; most jurisdictions require a permit and inspection for energy storage. Place the battery in a dry space kept above freezing; BigBattery's published charge range starts at 32°F.

Warranty & Support

Battery: covered by BigBattery's 12-Year Limited Warranty — in BigBattery's words, “BigBattery, Inc. guarantees that its products will be free from defects in material and workmanship for a period of twelve (12) years.” No registration needed, per BigBattery. Inverter: the EG4 6000XP carries a 5-year full parts replacement or full product replacement warranty, per EG4, which states the warranty “must be registered within the first year of purchase or provide proof of purchase from an EG4 authorized distributor to remain valid.”

BigBattery publishes a 30-Day Money Back Guarantee; per BigBattery, non-defective returns are refunded at purchase price minus a 20% restocking fee, excluding shipping. All returns require a Return Merchandise Authorization (RMA) before anything ships back — call OffGrid Horizon at (302) 496-3554 and we'll open the RMA or warranty claim. We're a family-owned authorized BigBattery partner, and BigBattery backs its batteries with lifetime USA-based technical support.

Shipping

This kit ships as palletized freight within the United States. Inspect the pallet before signing: note any damage on the delivery receipt and contact us promptly — that notation keeps a freight claim simple.

Frequently Asked Questions

Is this a grid-tie system?

No — the 6000XP is an off-grid inverter. Per BigBattery, the pairing is sold for home backup and off-grid operation, not as a grid-interactive (sell-back) system.

Will the NEXUS communicate with the 6000XP?

Per BigBattery, the NEXUS is compatible with all EG4 inverters, with RS485 / RJ45 / CAN communications built in. Call us if you want help with settings at commissioning.

Are solar panels included?

No. The 6000XP accepts up to 8,000W of PV per EG4; panels and racking are sized to your site and sold separately.

Can I add more storage later?

Yes — NEXUS batteries parallel up to 15 units, per BigBattery. The 2- and 3-battery versions of this kit are listed separately.

What about the inverter warranty registration?

Per EG4, register the inverter within the first year or keep proof of purchase from an authorized distributor. Keep your order confirmation either way — and call us if you'd like a hand with registration.

Do I need an electrician?

Yes — AC interconnection, grounding, and code compliance are work for a licensed electrician, and most jurisdictions require a permit and inspection.

Deciding between the 6000XP and the 12000XP V2? Call OffGrid Horizon at (302) 496-3554 — we're a family-owned authorized BigBattery partner and we'll size it with you honestly.

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