This is a 48V LiFePO4 battery system — the BigBattery NEXUS — paired with an EG4 6000XP inverter, sold as a packaged off-grid ESS (Energy Storage System). One NEXUS unit stores 14.3kWh at 280Ah capacity. It is built for home back-up and off-grid use, not for starting engines or powering mobile RV/marine loads.
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 Matters (Field Perspective)
A single NEXUS module gives you 14.3kWh of usable-class capacity at 280Ah / 48V. In practical terms, that's enough stored energy to run a refrigerator, well pump, and general household circuits through an evening outage, with headroom for larger draws thanks to the 140A continuous / 270A peak discharge rating. The system is designed to scale: BigBattery states parallel expansion up to 15 units per inverter, for a total of 214.5kWh — which moves this from "backup battery" territory into a real off-grid home power plant conversation.
Battery Characteristics
- Chemistry: LiFePO4 (Lithium Iron Phosphate)
- Nominal Voltage: 48V
- Capacity: 280Ah (14.3kWh per unit)
- Format: Stackable, modular ESS enclosure with included mounting hardware
- Included Inverter: EG4 6000XP
Wiring & Configuration Limits
NEXUS supports parallel expansion up to 15 units per inverter, bringing total capacity to 214.5kWh. It is also parallel-compatible with legacy KONG and GRIZ products purchased between 2019 and 2024, per the manufacturer. DATA provided does not specify a series-stacking configuration or a maximum series count for NEXUS — treat this as a parallel-expansion architecture only unless your Resources tab documentation states otherwise.
NOT confirmed for: series wiring beyond what is documented in manufacturer resources. Do not assume series expansion is supported without verifying in the manufacturer's Product Specifications tab. NOT for use as: a starter/cranking battery, or in mobile RV/marine applications — this is a stationary home/off-grid ESS.
Pro-Installer Tip
Paralleling lithium modules from different production runs or state-of-charge levels is the most common cause of imbalance-driven BMS lockouts in ESS installs. Before tying multiple NEXUS units together, charge each module to the same voltage independently and confirm balance with a shunt-based battery monitor before final interconnection. This prevents one module from carrying a disproportionate share of the load, which shortens cycle life and can trip BMS protection on the weaker unit. When cycling the system day to day, keep discharge depth within the 80-100% DoD range typical for LiFePO4 — but size your daily draw so the inverter isn't consistently forcing the pack to its low-voltage cutoff, which accelerates cell stress over years of use.
Key Benefits
- All-weather thermal management: charges from 32°F to 113°F, discharges down to -4°F
- Handles high-demand loads: 140A continuous, 270A peak discharge per unit
- Scales to a full off-grid power plant: up to 15 units in parallel, 214.5kWh total
- RS485, CAN, and RJ45 ports for system communication, automation, and monitoring
- Backward compatible with legacy KONG and GRIZ battery lines (2019-2024 purchases)
- Ships as a packaged system with the EG4 6000XP inverter and setup hardware included
Technical Table
| Spec | Value |
|---|---|
| Voltage | 48V |
| Capacity | 280Ah |
| Energy | 14.3kWh |
| Chemistry | LiFePO4 |
| Max Continuous Discharge | 140A |
| Peak Discharge | 270A |
| Charging Temperature Range | 32°F to 113°F |
| Discharging Temperature Range | Down to -4°F |
| Max Parallel Units | 15 |
| Total Parallel Capacity | 214.5kWh |
| Communication Ports | RS485, CAN, RJ45 |
| Included Inverter | EG4 6000XP |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
Compatibility & Fitment
Compatible with: Legacy KONG and GRIZ battery products purchased between 2019 and 2024, for parallel expansion. Ships packaged with the EG4 6000XP inverter as an integrated ESS.
NOT compatible with / NOT included: This listing does not include a standalone charger for standard lead-acid systems — standard lead-acid chargers are NOT recommended for this LiFePO4 pack. Series-stacking configuration is NOT confirmed in the source data — do not wire units in series without verifying manufacturer documentation. This is NOT a starter battery and is NOT intended for RV or marine mobile applications. Cranking amp (CCA) ratings do not apply to this product; it is rated in Ah and continuous/peak discharge amps only.
FAQ
Q: What chemistry is the NEXUS battery?
A: LiFePO4 (Lithium Iron Phosphate), 48V nominal.
Q: How many NEXUS units can I run together?
A: Up to 15 units in parallel per inverter, for a total of 214.5kWh.
Q: Can I mix NEXUS with my existing KONG or GRIZ batteries?
A: Yes, NEXUS is parallel-compatible with legacy KONG and GRIZ products purchased between 2019 and 2024.
Q: Can this battery be charged in freezing temperatures?
A: Charging is rated from 32°F to 113°F. Discharging is supported down to -4°F. Charging below 32°F is not specified as supported in the manufacturer data — verify low-temperature charging protection details in the Resources tab before operating near freezing.
Q: What inverter is included with this system?
A: The EG4 6000XP inverter is included and packaged with the NEXUS battery for a complete ESS setup.
Warranty & Support
Warranty terms and full manufacturer documentation are provided in the "Resources (System Manuals and Warranty)" Tab above. Ask us before you order if you're unsure how many NEXUS units your load profile calls for — we always reply back.
