BigBattery NEXUS + APEX 6.5K Battery Storage Bundle [15kWh–45kWh] | Indoor Only | 10,000W PV Input / 6,500W AC Output | 5-Year Inverter + 12-Year Battery Warranty

Meet the BigBattery NEXUS + APEX 6.5K Battery Storage Bundle—a clean, scalable ESS built for off-grid power and serious backup performance. Pair the APEX-6.5K split-phase hybrid inverter with 1–3× NEXUS 15kWh LiFePO₄ batteries to build 15kWh, 30kWh, or 45kWh of storage, all on a 48V platform.

This bundle is designed to keep things simple: true 120/240V pure sine wave power, big solar input (10,000W total), and the flexibility to charge from solar plus grid/generator when conditions change. On the storage side, NEXUS adds a rugged floor-standing design with built-in protections, self-heating for cold-weather charging, and integrated aerosol fire suppression—so you can build with confidence and scale as your power needs grow.

Key Features & Benefits

• Choose your storage: 1×, 2×, or 3× NEXUS (15kWh–45kWh) - Build the capacity you need now and expand later without replacing your core system.

• True split-phase 120/240V pure sine wave (50/60Hz) - Run essential circuits and larger appliances that require real 120/240V power.

• 6,500W rated output (13,000VA max) - Strong output with surge capability for demanding loads.

• 10,000W PV input with dual MPPT (5,000W + 5,000W) - Capture more solar and support larger arrays for greater day-to-day autonomy.

• Solar + grid/generator charging support (2 AC inputs: Grid & Generator) - Stay powered when sunlight drops—charge and run loads through changing conditions.

• Fast charging capability - Up to 140A solar charge and 80A grid/generator charge for quicker recharge cycles.

• LiFePO4 + integrated BMS protections (NEXUS) - A safer, stable battery chemistry with built-in protection controls.

• Cold-weather ready (NEXUS self-heating) - Improves charging reliability in colder environments.

• Integrated aerosol fire suppression (NEXUS) - Adds an extra layer of safety inside the battery unit.

• Wide battery operating temps - Charge 32°F–113°F, discharge -4°F–113°F for dependable seasonal performance.

• 12-Year Warranty - Long-term coverage to protect your investment.
  

Specs in a Glance: 

Inverter (BigBattery APEX-6.5K)

• Output: 6,500W rated, 13,000VA max

• Output Voltage: 120/240 Vac split-phase

• Battery Voltage: 48V nominal system, 40–60Vdc range

• Solar Input: Dual MPPT (1+1), 5,000W + 5,000W, 18A + 18A, 125–450Vdc MPPT range, 550Vdc + 550Vdc Voc max

• Max charging: 140A solar, 80A grid/generator, 140A hybrid

• AC Inputs: 2 inputs (Grid & Generator)

• Dimensions / Weight: 25.51 × 16.14 × 5.51 in, 48 lbs

• Certifications: UL1741, RoHS, FCC Part 15 Class B, IEC62109-1/-2, EN61000 (per spec sheet)

• Warranty: 5 years

Battery (BigBattery NEXUS 15kWh LiFePO4) — per battery

• Usable Energy: 15kWh

• Voltage: 48V system, 51.2V nominal

• Capacity: 300Ah

• Max Continuous Discharge: 140A (Max continuous power 7.6kW)

• Peak Discharge: 270A (1s)

• Communications: RS485 / RJ45 / CAN

• Protection Rating: IP54

• Installation: Indoor floor-standing

• Dimensions / Weight: 19.7 × 27.5 × 15.7 in, ~315 lbs

• Battery warranty: (Confirm) (not provided in the supplied specs)

What’s Included:

• 1× BigBattery APEX 6.5K off-grid hybrid inverter

• Choose: 1× / 2× / 3× BigBattery NEXUS 15kWh LiFePO4 battery

Ideal For:

• Off-grid cabins, homesteads, and remote residences needing true 120/240V split-phase power

• DIY-friendly ESS builds that need scalable storage (15–45kWh) now, with room to expand later

• Hybrid systems using solar + generator charging capability

User Manual / Documents:

• BigBattery 48V 15kWH NEXUS LiFePO4 Battery Spec Sheet
• BigBattery 48V 15kWH NEXUS LiFePO4 Battery User Manual
• BigBattery APEX 6.5K Off-Grid Hybrid Inverter Spec Sheet
• BigBattery APEX 6.5K Off-Grid Hybrid Inverter User Manual