Big Battery | Nexus + EG4 1200XP
Big Battery | NEXUS + EG4 12000XP Power System
The BigBattery NEXUS + EG4 12000XP Power System is a powerful, all-in-one home and off-grid energy solution that combines the 48V 14.3kWh NEXUS LiFePO4 battery with the EG4 12000XP hybrid inverter. This setup delivers 14.3kWh of energy storage and a robust 12,000W split-phase AC output, providing reliable, scalable backup or off-grid power for homes, cabins, and small businesses. Designed for efficiency and longevity, it features advanced CATL LFP cells, intelligent battery management, and high solar input capacity for energy independence.
KEY FEATURES
- 14.3kWh energy storage with long-lasting LiFePO4 chemistry
- 12,000W continuous split-phase output (120V/240V)
- Supports grid-tie, off-grid, and hybrid configurations
- 15,000W max solar PV input with dual MPPT tracking
- 99% MPPT efficiency and 0.99 power factor
- 7,000+ cycle lifespan with CATL cells
- Parallel operation for system expansion
- Full smart BMS with CAN/RS485 communication
- Ideal for residential, commercial, or backup applications





Specifications
AC INPUT
| Nominal AC Voltage: | 120/240VAC | 120/208VAC (L1/L2/N required) |
| Frequency (Grid | Generator): | 60 Hz (Default) | 50 Hz (Configurable) |
| Max. Continuous AC Current (Grid | Generator): | 100A @ 240VAC | 62.5A @ 240VAC |
| Max. AC Input Power: | 24000W |
| AC Bypass (Grid | Generator): | 100A | 90A |
| Recommended Generator Capacity: | 6000W – 15000W |
AC OUTPUT
| Output Voltage: | 120/240VAC | 208VAC |
| Output Frequency: | 60 Hz (Default) | 50 Hz (Configurable) |
| Max. Continuous Output Current: | 50A @ 240VAC | 57.7A @ 208VAC |
| Nominal Output Power (without PV): | 12000W @ 240V | 12000W @ 208V |
| Nominal Output Power (with PV): | 12000W @ 240V | 12000W @ 208V |
| Max. Continuous Wattage: | 12000W (L1/L2) | 6000W (L1-N/L2-N) |
| Surge Capacity: | 18000W (5 sec) | 15000W (10 sec) |
| Power Factor: | 0.99 |
| Total Harmonic Distortion: | <3% |
| Switching Time: | <10 ms (Single) | <20 ms (Parallel) |
PV INPUT
| No. of MPPTs (Inputs per MPPT): | 2 (2) |
| Max. Input Current: | 35A / 35A |
| Max. Short Circuit Input Current: | 44A / 44A |
| DC Input Voltage Range: | 100 – 480VDC |
| Min. Start Up Voltage: | 100VDC |
| MPPT Operating Voltage Range: | 120 – 385VDC |
| Nominal MPPT Voltage: | 320VDC |
| Max. Utilized PV Power: | 24000W (12000W per MPPT) |
| Max. Recommended PV Input: | 28000W (14000W per MPPT) |
| Max. Efficiency: | 99% (MPPT) | 93.5% (PV to Loads) | 92.8% (PV to Battery) | 92.5% (AC to Battery) | 90.2% (Battery to Loads) |
| Idle Consumption (Standby Mode): | <70W |
BATTERY
| Nominal Voltage: | 48VDC |
| Battery Voltage Range: | 46.4 – 60VDC |
| Max. Charge / Discharge Current: | 250A |
| Max. Charge / Discharge Power: | 12000W |
| DC Cut-Off Voltage: | 59VDC |
| Recommended Battery Capacity per Inverter: | >400Ah |
OPERATING ENVIRONMENT
| Max. Parallel Connections: | 6 |
| Protection Rating: | IP20 |
| Communication Interface: | RS485 / CANBus / WiFi |
| Operating Temperature (Full Load): | 32ºF – 113ºF (0ºC – 45ºC) |
| Storage Temperature: | 5ºF – 140ºF (-15ºC – 60ºC) |
| Altitude: | <6,561 ft (2000 m) |
| Relative Humidity (Non-Condensing): | 5 – 95% |
| Typical Noise Emission: | <60 dB |
| Cooling Method: | Fan |
DIMENSIONS
| Weight: | 104.7 lbs (47.5 kg) |
| Depth: | 5.9 in (150 mm) |
| Width: | 20.9 in (530 mm) |
| Height: | 34.25 in (870 mm) |
Manual & Downloads
Are Solar Guys Pro Authorized Retailers?
Yes! We are proud to be one of the few online retailers who are authorized retailers for every single product we carry!
Being an authorized retailer means we carry the same warranty as the manufacturer, protecting your purchase!
When Will My Order Ship?
Most orders ship within 1–3 business days. You’ll get a tracking number as soon as it ships via email!
Do We Accept Returns?
Yes absolutely, we have a no-hassle, 30-day return policy on all items! To refer to the full policy, click HERE
Are Products Brand New?
Yes! By default, all products on Solar Guys Pro are 100% brand-new and in perfect condition.
If an item is used or refurbished, it will clearly indicate so in the title of the product as well as the discription.
For example, a used Battery will say:
XYZ Battery | 48V 100AH (REFURBISHED)
If you'd like to confirm, you can always send us a email at info@solarguyspro.com
Orders over $500 include a FREE (Normally $149.99) 80-Page DIY Solar eBook — added automatically at checkout.
Frequently Asked Questions
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