BigBattery NEXUS 2 Battery + EG4 12000XP Inverter — 16kWh Off-Grid ESS System
This system pairs the BigBattery NEXUS 2 — a 48V LiFePO4 battery rated at 314Ah and 16kWh — with the EG4 12000XP off-grid inverter. Together they form a split-phase, 120/240V off-grid power system built for homes, cabins, workshops, and backup power applications. The battery is LiFePO4 (Lithium Iron Phosphate) chemistry with an integrated BMS.
Note: If you would like to review the manufacturer Product Specifications, Warranty, Brochure, etc., for this system, please refer to the "Resources (System Manuals and Warranty)" Tab above on this page.
Why This Pairing Matters
Off-grid systems fail buyers most often when the battery and inverter are sized incorrectly against each other. This listing pairs a specific battery (NEXUS 2, 314Ah/16kWh) with a specific inverter (EG4 12000XP, 12,000W continuous) so you know exactly what output and runtime you're buying — not a generic "compatible with most inverters" claim. The NEXUS 2 uses LiFePO4 cells rated for more than 8,000 cycles, translating to over 12 years of service life under daily cycling in appropriate operating conditions. The 314Ah capacity at 48V nominal yields 16kWh of stored energy per battery — the number to use when sizing your daily load against available runtime.
Battery Characteristics
Chemistry: LiFePO4 (Lithium Iron Phosphate). The NEXUS 2 is a floor-standing enclosure rated IP54, suitable for indoor or outdoor installation. It includes an integrated BMS with multiple safety redundancies and communicates via RS485 and CAN interfaces for closed-loop integration with supported inverters, including the EG4 12000XP.
Wiring & Configuration Limits
One NEXUS 2 battery supports up to 7.6kW of continuous battery-powered output. Because the EG4 12000XP is rated for 12,000W continuous, two NEXUS 2 batteries are recommended to support the inverter's full output capacity. The battery bank can be expanded up to 15 NEXUS 2 units in parallel, with a maximum rated configuration of up to 240kWh. On the inverter side, up to 16 EG4 12000XP units can be paralleled for larger installations.
NOT for use as a starter battery. The NEXUS 2 is not rated for series stacking beyond its 48V nominal configuration as shipped — expansion is achieved via parallel connection only, not series. Standard lead-acid chargers are NOT recommended for this battery; use only the EG4 12000XP or another charge source compatible with its BMS communication profile.
Pro-Installer Tip
Parallel expansion of lithium batteries is not the same as wiring lead-acid banks — mismatched state-of-charge between NEXUS 2 units at first parallel connection can trigger BMS current-limiting or lockout as the system tries to balance cells across units. Left uncorrected, this leads to premature capacity fade in the weaker unit and inconsistent discharge behavior across the bank. Before connecting a second or third NEXUS 2 in parallel, charge each unit individually to a matching state of charge and verify voltage agreement with a shunt-based battery monitor before joining busbars. LiFePO4 chemistry supports 80-100% depth of discharge, but consistent full-depth cycling across an unbalanced bank shortens usable cycle life well below the rated 8,000+ cycles.
Key Benefits
- 16kWh of LiFePO4 storage per battery, expandable to 240kWh across 15 parallel units
- 150A continuous discharge with 270A peak for one-second startup surges [NEEDS VERIFICATION: peak discharge duration and current not independently confirmed in source table]
- 8,000+ rated cycles — over 12 years of service under daily cycling
- Integrated BMS with multiple safety redundancies and RS485/CAN communication
- 12,000W continuous split-phase (120/240V) output from the EG4 12000XP, with 15,360W surge for approximately 10 seconds
- Dual high-voltage MPPTs utilizing up to 24,000W of solar, across a 100-480VDC input range
- Fast transfer time of less than 10ms with a single inverter
- Remote monitoring via plug-in Wi-Fi and the EG4 app / EG4 Monitor Center
- Maintenance-free LiFePO4 operation — no routine servicing required
Technical Table
| Spec | Value |
|---|---|
| Chemistry | LiFePO4 |
| Nominal Voltage | 48V |
| Capacity (Ah) | 314Ah |
| Energy Capacity | 16kWh |
| Continuous Discharge | 150A |
| Peak Discharge | 270A |
| Continuous Battery Power (per unit) | 7.6kW |
| Cycle Life | 8,000+ cycles |
| Enclosure | IP54, floor-standing |
| Communication Interfaces | RS485, CAN |
| Inverter Continuous Output | 12,000W |
| Inverter Surge Capacity | 15,360W (approx. 10 seconds) |
| Solar Input Utilized | 24,000W |
| Solar Input Range | 100-480VDC |
| Grid Bypass | 100A |
| Transfer Time | less than 10ms (single inverter) |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
Compatibility & Fitment
This listing pairs the BigBattery NEXUS 2 battery with the EG4 12000XP inverter as an integrated, optimized system. The battery communicates with the inverter over RS485 and CAN interfaces using supported closed-loop battery communication profiles. The system supports solar, battery, grid-assisted, and generator-assisted operation, with smart-load management and AC coupling. Generator integration is compatible with recommended generators rated from 6,000W to 15,000W.
NOT compatible with: standard lead-acid battery chargers; series-stacked battery configurations beyond the 48V nominal unit; generators outside the 6,000W-15,000W recommended range are not addressed by this specification and should be verified separately. This listing does NOT include generators, solar panels, PV cabling, or breakers — those are sourced separately.
Options & SKUs
| Variant | SKU | Price |
|---|---|---|
| variable parent (7 variations) | K0326-V | $5144.99 |
This product is listed as a variable parent covering 7 configuration variations. Only the base SKU and price above were provided; confirm individual configuration pricing before ordering. [NEEDS VERIFICATION: individual variant SKUs and prices for the 7 configurations were not provided in source data]
FAQ
Is the NEXUS 2 battery LiFePO4 or lead-acid?
The NEXUS 2 is a LiFePO4 (Lithium Iron Phosphate) battery, rated at 314Ah / 16kWh at 48V nominal.
How many NEXUS 2 batteries do I need to run the EG4 12000XP at full output?
One NEXUS 2 supports up to 7.6kW of continuous battery-powered output. Two NEXUS 2 batteries are recommended to support the inverter's full 12,000W continuous output.
Can I add more batteries later?
Yes. The NEXUS 2 battery bank can be expanded up to 15 units in parallel, for a maximum rated configuration of up to 240kWh. Series stacking beyond the 48V nominal unit is not supported — expansion is parallel only.
Does this system include solar panels or a generator?
No. This listing includes the NEXUS 2 battery and EG4 12000XP inverter only. Solar panels, PV cabling, and generators are not included. The system is compatible with recommended generators from 6,000W to 15,000W.
What is the warranty on this system?
The NEXUS 2 battery carries a 12-year warranty. The EG4 12000XP inverter carries a 5-year warranty. Lifetime USA-based technical support is included.
Warranty & Support
The NEXUS 2 battery is covered by a 12-year warranty. The EG4 12000XP inverter is covered by a 5-year warranty. Lifetime USA-based technical support is included. This system ships from Texas, USA. If you have questions about sizing your battery bank or inverter configuration before ordering, ask us — we always reply back.
