BigBattery NEXUS 2 + EG4 6000XP: 16kWh Off-Grid ESS System
This system pairs the BigBattery NEXUS 2 48V LiFePO4 battery with the EG4 6000XP split-phase off-grid inverter. It is built for homes, cabins, workshops, and backup-power installations that need a matched battery-and-inverter foundation rather than separately sourced components.
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.
Battery Characteristics
The NEXUS 2 is a 48V LiFePO4 (Lithium Iron Phosphate) battery rated at 314Ah, delivering 16kWh of usable energy storage. It ships in a floor-standing, IP54-rated enclosure suitable for indoor or outdoor placement. The battery uses an integrated Battery Management System (BMS) with multiple safety redundancies and communicates via RS485 and CAN interfaces for supported system integration. [NEEDS VERIFICATION: specific dimensions and weight not provided in source data.]
Wiring & Configuration Limits (Series/Parallel)
The NEXUS 2 battery bank can be expanded up to 15 batteries in parallel, reaching a maximum rated configuration of 241.5kWh. The EG4 6000XP inverter can be paralleled up to 16 units for expanded output capacity. This is a 48V architecture matched specifically to the EG4 6000XP's input requirements — the NEXUS 2 provides sufficient continuous power to support the inverter's full 6,000W rated output.
NOT rated for series expansion of the battery beyond its native 48V configuration. NOT a starter battery and NOT suitable for cranking applications. Standard lead-acid chargers are NOT recommended for this LiFePO4 system — use only the matched EG4 6000XP or a charge source compatible with the NEXUS 2's BMS communication protocol.
Pro-Installer Tip
Paralleling lithium batteries without matching state-of-charge across units is a common source of cell imbalance and premature BMS lockout. Before connecting additional NEXUS 2 units in parallel, bring each battery to a similar voltage and let the system rest before tying the bank together. This prevents one battery from being forced to absorb disproportionate charge or discharge current relative to the others, which shortens cycle life over time. Use a shunt-based battery monitor to confirm balanced state-of-charge across the bank before and after installation. As a professional standard, plan cycling around 80-100% depth of discharge (DoD) for this LiFePO4 chemistry, consistent with the 8,000+ cycle rating stated by the manufacturer.
Key Benefits
- 16kWh of LiFePO4 storage rated for more than 8,000 cycles — over 12 years of service under daily cycling
- 150A continuous discharge with 270A peak discharge for demanding off-grid and backup loads
- 6,000W continuous split-phase 120/240V output with 12,000W surge capacity for approximately 3.5 seconds
- Dual MPPT solar inputs utilizing up to 8,000W, with support for up to 10,000W of recommended connected PV capacity
- Integrated BMS with multiple safety redundancies and RS485/CAN communication
- Wi-Fi connectivity for remote monitoring and adjustment through EG4 software
- Maintenance-free LiFePO4 chemistry — no routine servicing required
Technical Table
| Spec | Value |
|---|---|
| Voltage | 48V |
| Capacity | 314Ah |
| Energy Storage | 16kWh |
| Chemistry | LiFePO4 |
| Max Continuous Discharge | 150A |
| Peak Discharge | 270A |
| Continuous Battery Power | 7.6kW |
| Cycle Life | 8,000+ cycles |
| Enclosure Rating | IP54 (floor-standing) |
| Inverter Continuous Output | 6,000W split-phase 120/240V |
| Inverter Surge Output | 12,000W (~3.5 seconds) |
| PV Input Utilized | 8,000W (dual MPPT) |
| Recommended PV Capacity | 10,000W |
| PV Voltage Range | 100-480VDC input, 120-385VDC MPPT operating range |
| Transfer Time | Less than 15ms (single inverter) |
| Communication | RS485, CAN |
| Max Parallel Batteries | 15 (up to 241.5kWh) |
| Max Parallel Inverters | 16 |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
Compatibility & Fitment
This is an integrated and optimized system: BigBattery NEXUS 2 48V LiFePO4 battery matched with the EG4 6000XP off-grid inverter. The battery bank can be expanded up to 15 units in parallel for a maximum rated configuration of 241.5kWh. Up to 16 EG4 6000XP inverters can be paralleled for expanded output. The system supports solar, battery, grid-assisted, and generator-assisted operation, using AC input for supplemental charging and load support when grid or generator power is available.
NOT compatible as a drop-in replacement for lead-acid battery banks without a system redesign. NOT for use as a cranking/starter battery. Standard lead-acid battery chargers are NOT recommended for charging the NEXUS 2. Series wiring of the NEXUS 2 battery beyond its native 48V rating is NOT supported.
FAQ
What chemistry does the NEXUS 2 battery use?
The NEXUS 2 uses LiFePO4 (Lithium Iron Phosphate) cells, rated for more than 8,000 cycles.
How many NEXUS 2 batteries can be connected in parallel?
Up to 15 NEXUS 2 batteries can be wired in parallel, for a maximum rated configuration of 241.5kWh.
What is the continuous output of the EG4 6000XP inverter?
The EG4 6000XP delivers 6,000W of continuous split-phase 120/240V output, with up to 12,000W of surge power for approximately 3.5 seconds.
Can this system run entirely off-grid?
Yes. The EG4 6000XP can operate entirely off-grid, or use grid or generator input for supplemental charging and load support.
Is the NEXUS 2 battery rated for outdoor installation?
Yes. The NEXUS 2 has a rugged IP54-rated, floor-standing enclosure suitable for indoor or outdoor installation.
Warranty & Support
This system carries a 12-year warranty on the NEXUS 2 battery and a 5-year warranty on the EG4 6000XP inverter. It ships from Texas, USA, and is backed by lifetime USA-based technical support. If you have questions about parallel configuration limits or charging setup before you order, ask us — we always reply back.
