This system pairs a BigBattery 48V NEXUS 14.3kWh LiFePO4 battery with the APEX-10K split-phase hybrid inverter. It's built as a packaged energy storage system (ESS) for cabins, homesteads, and off-grid residences that need whole-home 120/240V power, not a single component sold in isolation.
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
The NEXUS battery bank and APEX-10K inverter are designed to run together as a matched ESS. The inverter's split-phase 120/240V output and 80A pass-through are engineered around LiFePO4 battery banks like NEXUS, so the pairing avoids the guesswork of matching mismatched third-party components. This page covers what's confirmed in the manufacturer data: chemistry, capacity, voltage, inverter I/O, and physical build. Where the manufacturer data doesn't specify a number (cycle life, exact Ah rating, BMS discharge/charge amperage, weight, dimensions, terminal type, operating temperature range, or cold-weather charging protection), it's flagged below rather than guessed.
Battery Characteristics
- Chemistry: LiFePO4 (Lithium Iron Phosphate)
- Nominal Voltage: 48V
- Capacity: 14.3 kWh
- Cycle Life: [NEEDS VERIFICATION]
- Max Continuous Discharge / Charge (BMS): [NEEDS VERIFICATION]
- Peak Discharge: [NEEDS VERIFICATION]
- Low-Temperature Charging Protection: [NEEDS VERIFICATION] — the manufacturer text notes "wide operating temperatures" for the inverter enclosure but does not state a battery-side cold-weather disconnect or internal heating spec.
- Group Size / Dimensions / Weight: [NEEDS VERIFICATION]
- Terminal Type: [NEEDS VERIFICATION]
Inverter Characteristics (APEX-10K)
- Output: Split-phase 120/240V, 50/60 Hz, pure sine wave
- Pass-Through: 80A
- Inputs: Grid, Load, Generator (single AC input — supports grid OR generator, not simultaneously), BAT–, BAT+, PV, Parallel Connection, USB, WiFi, RS485/CAN, Dry Contact. CT input is not supported on the 10K (APEX-6.5K only).
- Enclosure: Outdoor-rated, bottom-entry wiring for installer access
Wiring & Configuration Limits
The manufacturer data confirms this system supports parallel connection between inverter units for expanded capacity or output. It does not specify a maximum parallel unit count, maximum battery series/parallel expansion for the NEXUS bank, or a total kWh scaling ceiling. Do not assume unlimited parallel stacking — confirm exact expansion limits against the manufacturer specification sheet referenced in the Resources tab before ordering additional units.
Confirmed: Parallel connection supported (inverter-to-inverter), per input table.
NOT confirmed / do not assume: Maximum number of parallel inverters, maximum battery banks per inverter, series wiring of NEXUS batteries beyond the 48V nominal configuration shipped. [NEEDS VERIFICATION]
Pro-Installer Tip
Parallel-connecting hybrid inverters without confirming the manufacturer's exact unit limit is a common point of failure in off-grid builds. Exceeding an unlisted parallel cap — or mixing firmware/hardware revisions across units — can cause communication faults between inverters and put uneven charge/discharge load on the battery bank, accelerating cell imbalance over time. Before adding a second APEX-10K or additional NEXUS battery, verify the documented parallel limit and battery bank sizing in the manufacturer spec sheet, and monitor pack-level voltage with a shunt-based battery monitor during the first several cycles. LiFePO4 systems like NEXUS are typically built for 80-100% depth of discharge, but this figure should be confirmed against the spec sheet rather than assumed, since it is not stated in the provided manufacturer data.
Key Benefits
- Whole-home split-phase 120/240V output for running larger appliances and essential circuits together, not just single-outlet loads.
- LiFePO4 chemistry paired to the inverter, avoiding the compatibility guesswork of sourcing battery and inverter separately.
- Solar and generator input support, so the system can keep charging when sunlight is limited.
- 80A pass-through rating for demanding loads.
- Installer-friendly bottom-entry wiring and an outdoor-ready enclosure for remote installations.
Technical Table
| Spec | Value |
|---|---|
| Voltage | 48V |
| Capacity | 14.3 kWh |
| Chemistry | LiFePO4 |
| Inverter Output | Split-phase 120/240V, 50/60 Hz, pure sine wave |
| Pass-Through Rating | 80A |
| Cycle Life | [NEEDS VERIFICATION] |
| Max Continuous Discharge/Charge (BMS) | [NEEDS VERIFICATION] |
| Dimensions / Weight | [NEEDS VERIFICATION] |
| Terminal Type | [NEEDS VERIFICATION] |
| Operating Temp Range | [NEEDS VERIFICATION] |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
Compatibility & Fitment
Compatible with: Solar (PV) input and generator input for charging, per the confirmed inverter input table. Parallel connection between APEX inverter units is supported for system expansion.
NOT confirmed / NOT included:
- This listing does NOT include a UPC/GTIN — none was provided by the manufacturer and none has been assigned here.
- On the APEX-10K, grid and generator share a single AC input — they are NOT usable simultaneously (grid or generator, not both at once). This differs from the APEX-6.5K.
- CT input is NOT available on the APEX-10K (6.5K model only).
- Standard lead-acid chargers are NOT appropriate for this LiFePO4 bank; use only chargers/inverters compatible with the NEXUS BMS communication protocol.
- Maximum series/parallel expansion limits for the battery bank are NOT stated in manufacturer data provided — confirm before purchasing additional units.
- This is NOT a starter battery and is not intended for cranking applications.
FAQ
What chemistry is the NEXUS battery?
LiFePO4 (Lithium Iron Phosphate), rated at 48V nominal with 14.3 kWh capacity.
Can the APEX-10K run on generator and grid power at the same time?
No. The APEX-10K has a single AC input that supports either grid or generator power, not both simultaneously. This is different from the APEX-6.5K.
Can I connect more than one APEX-10K inverter together?
The inverter supports parallel connection per the manufacturer's input table, but the exact maximum number of units is not specified in the available data. Confirm the parallel limit in the manufacturer specification sheet before adding units.
What is the pass-through rating of the APEX-10K?
80A, intended to keep larger appliances and critical circuits running.
Does this system include a UPC or GTIN?
No. No UPC/GTIN was provided by the manufacturer for this SKU.
Warranty & Support
Warranty terms for the NEXUS battery and APEX-10K inverter are not included in the data provided here. Refer to the "Resources (System Manuals and Warranty)" Tab above for the manufacturer's warranty documentation before you order. If anything on this page doesn't match what you find in those documents, ask us before you order — we always reply back.
