Product Description

A compact off-grid package: three stackable BigBattery ETHOS 48V 5.12 kWh LiFePO4 modules — 15.36 kWh in a single tower — paired with the EG4 6000XP off-grid inverter. Per EG4, the 6000XP delivers 6 kW of split-phase 120/240V output, accepts 8 kW of PV input through dual MPPTs, and idles as low as 30W with PV. Per BigBattery, ETHOS and the 6000XP run closed-loop communication for coordinated charging and accurate state-of-charge reporting.

Who This System Is For

Cabins, tiny homes, and well-defined essential-loads backup: refrigeration, lighting, electronics, a water pump, and a moderate 240V load. Six kilowatts covers that mix comfortably, and 15.36 kWh typically carries an efficient small household overnight. If your load list includes heavy simultaneous 240V equipment, step up to the ETHOS + EG4 12000XP V2 kit instead.

Key Features

  • 15.36 kWh of LiFePO4 storage — three 5.12 kWh / 100Ah ETHOS modules in one small-footprint tower
  • 6 kW continuous split-phase 120/240V output with 8 kW of PV input via dual MPPTs, per EG4
  • Certified battery platform: UL9540, UL9540A, UL1973, and UN38.3, per BigBattery; the 6000XP is UL 1741 certified, per EG4
  • Closed-loop communication between ETHOS and the inverter, per BigBattery
  • Generator-ready: dedicated GEN port accepts up to 7 kW, per EG4
  • Low idle draw: as low as 30W with PV, per EG4 — meaningful on small daily energy budgets
  • Room to grow: add ETHOS modules (up to 16 parallel connections per control box, per BigBattery) or parallel up to 16 inverters for 96 kW combined, per EG4

Why BigBattery

BigBattery is a US-based energy storage company that has been building lithium battery systems since 2011 and, per BigBattery, is trusted by more than 50,000 Americans. BigBattery states its products are designed and engineered in Texas, includes free lifetime tech support with every product, and backs its batteries with a 12-Year Limited Warranty — described by BigBattery as "the longest warranty in the battery industry." OffGrid Horizon is a family-owned authorized BigBattery partner.

What's In the Kit

  • 1 × EG4 6000XP all-in-one off-grid inverter
  • 3 × BigBattery ETHOS 48V 5.12 kWh LiFePO4 modules — one 15.36 kWh tower

BigBattery lists ETHOS inverter connectors and battery-to-battery connectors as separate accessories — call (302) 496-3554 to confirm the cabling and accessories included with your order. Solar panels, racking, and array wiring are sold separately.

Specifications

Battery BigBattery ETHOS, stackable LiFePO4 — see the ETHOS battery system
Capacity 15.36 kWh / 300Ah (3 × 5.12 kWh / 100Ah modules), 51.2V nominal
Max continuous discharge 250A (12,800W), per BigBattery
Dimensions / weight (3-module tower) 26.5" W × 6.7" D × 59.8" H; 387 lb, per BigBattery
Battery communications CAN bus / RS485; closed-loop with EG4, per BigBattery
Battery certifications UL9540, UL9540A, UL1973, UN38.3, per BigBattery
Cycle life 3,500–5,000 cycles (80% DoD, 0.5C), per BigBattery's spec sheet
Charge temperature 32°F to 113°F (discharge -4°F to 140°F)
Battery warranty BigBattery 12-Year Limited Warranty
Inverter EG4 6000XP all-in-one off-grid (per EG4)
AC output 6,000W continuous, split-phase 120/240V
PV input 8,000W max via dual MPPTs
Grid / generator Grid input for supplemental charging; GEN port up to 7 kW
Parallel capability Up to 16 units (96 kW combined), per EG4
Idle consumption As low as 30W with PV, per EG4
Inverter certifications UL 1741, per EG4
Inverter warranty 5-year, per EG4

Grid-Tied, Off-Grid, or Backup?

The 6000XP is an off-grid inverter: it does not export power to the utility. Per EG4, it can accept grid input for supplemental battery charging, and its GEN port supports up to 7 kW of generator input — so it works fully off-grid, or as a non-export backup system in a grid-connected home. Backup coverage is load-dependent: 6 kW carries a defined set of essential circuits, not an entire large home running everything at once.

Installation

Stacking the modules and mounting the inverter are manageable tasks, but all AC wiring — panel interconnection, grounding, bonding, and overcurrent protection — must be performed by a licensed electrician in accordance with the National Electrical Code (NEC) and local amendments. Even off-grid and non-export systems typically require a permit and inspection in most jurisdictions. No utility interconnection agreement is needed since the 6000XP does not export to the grid.

Warranty & Support

Battery — BigBattery 12-Year Limited Warranty. Per BigBattery: "If any covered component within your battery fails due to a defect in materials or workmanship within the 12-year warranty period, we will repair or replace the battery at our cost." Included accessories carry a 1-year warranty per BigBattery, and BigBattery provides free lifetime tech support for all its products.

Inverter — 5-year warranty, per EG4. Per EG4, inverter warranties must be registered within the first year of purchase (or proof of purchase from an EG4 authorized distributor provided) to remain valid.

Returns and warranty claims require an RMA. Contact us before shipping anything back — all returns must be authorized with a Return Merchandise Authorization first. OffGrid Horizon is a family-owned authorized BigBattery partner: call (302) 496-3554 and we will help open the claim and coordinate service.

Shipping

This kit ships as palletized LTL freight within the continental United States; curbside liftgate delivery is standard for residential addresses. The three-module ETHOS tower weighs 387 lb per BigBattery, plus the inverter — plan for help on delivery day. Before signing the delivery receipt, count the pieces and inspect the packaging; note any damage or shortage on the receipt with the driver and contact us immediately so we can open a freight claim. Per BigBattery, standard domestic orders are projected to take 7–12 days to deliver.

Frequently Asked Questions

Is 6 kW enough for my place?

For a cabin, tiny home, or defined essential circuits — refrigeration, lights, electronics, a water pump, one moderate 240V load — yes, comfortably. If your list includes heavy simultaneous 240V loads (large A/C plus well pump plus shop tools), look at the 12000XP V2 kit instead.

Can it sell power back to the grid?

No. The 6000XP is an off-grid inverter; per EG4 it accepts grid input for supplemental charging but does not export to the utility.

Does it support a generator?

Yes — per EG4, a dedicated GEN port accepts up to 7 kW of generator input for charging when solar falls short.

Are solar panels included?

No. The 6000XP accepts up to 8 kW of PV via dual MPPTs, per EG4; panels, racking, and wiring are sized to your site and sold separately. The system also runs as a grid- or generator-charged battery system without solar.

Can I expand later?

Yes — add ETHOS modules in 5.12 kWh steps (up to 16 parallel connections per control box, per BigBattery), or parallel additional 6000XP units, up to 16 total per EG4.

How does LiFePO4 handle cold weather?

Per BigBattery, ETHOS discharges down to -4°F, but charging is restricted below 32°F by the BMS to protect the cells. Install the tower in an insulated or conditioned space to keep charging available year-round.

Building out a cabin or homestead system? Call OffGrid Horizon at (302) 496-3554 — we're a family-owned authorized BigBattery partner and will help you match the kit to your load list.

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