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BigBattery NEXUS 51.2V 15kWh LiFePO4 Battery + EG4 12000XP 12,000W 48V Split Phase Off-Grid Inverter Kit

SKU: K0154
Save $6,517.50 Save $1,390.00
Original price $6,950.00
Original price $6,950.00 - Original price $32,587.50
Original price $6,950.00
Current price $5,560.00
$5,560.00 - $26,070.00
Current price $5,560.00
Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
Bundle Options: 1 x NEXUS Battery + EG4 12000XP Inverter

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Product Highlights

NEXUS LiFePO₄ modules (15kWh each) pair with the EG4 12000XP delivering 12,000W split-phase per inverter and up to 24,000W PV input, ideal for grid-tied or off-grid whole-home and commercial backup; systems scale from 15kWh to 225kWh and up to 36kW output. Featuring dual MPPTs, built-in breakers, a 15–30ms UPS transfer switch, and remote monitoring, they ensure seamless and efficient performance. Lightweight and transformer-free, they support smart load control, AC coupling, and peak shaving to reduce energy costs while providing reliable backup power.

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BigBattery NEXUS 51.2V 15kWh LiFePO4 Battery + EG4 12000XP 12,000W 48V Split Phase Off-Grid Inverter Kit

BigBattery NEXUS 51.2V 15kWh LiFePO4 Battery + EG4 12000XP 12,000W 48V Split Phase Off-Grid Inverter Kit

Introducing the Nexus

Legacy Product Parallel Compatibility

The NEXUS is compatible and parallel-able with all existing KONG and GRIZ products purchased between 2019-2024.

 

Specifications:

BigBattery NEXUS 51.2V 15kWh LiFePO4 Battery
System Voltage 48V
Nominal Voltage 51.2V
Chemistry LiFePO4
Usable Energy (kWh) 15kWh
Ah Capacity 300Ah
Cell Configuration 16S1P
Max Continuous Discharge 100A
Max Discharge Power 7.6kW
Max Discharge Peak 110A
Max Charge Current 100A
Charging Voltage Range 53.5V-57.6V
Operating Voltage Range 48V-57.6V
Max Charge Voltage 57.9V
Suggested Low Voltage Cutoff 50.8V
Charge Temp Range 32°F to 113°F
Discharge Temp Range -4°F to 113°F
Optimal Discharge Temp 59°F to 95°F
Storage Temp Range (SoC >50%) -4°F ~ 77°F
Humidity Range 10%-95% (No Condensation)
Weight (kg) ~142.8 kg ±5
Dimensions (WxHxD) 19.7 in x 27.5 in x 15.7 in
Altitude Limit <2000m
Max Connections 15 in parallel (up to 225kWh)
Communications RS485 / RJ45 / CAN
Protection Rating IP21
Certifications UN38.3
Installation Indoor Floor-standing
EG4 12000XP 12,000W 48V Split Phase Off-Grid Inverter
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
Storage Temperature 5ºF – 140ºF
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
Depth 5.9 in
Width 20.9 in
Height 34.25 in

PACKAGE INCLUDES

BigBattery NEXUS 51.2V 15kWh LiFePO4 Battery + EG4 12000XP 12,000W 48V Split Phase Off-Grid Inverter

BigBattery NEXUS 51.2V 15kWH LiFePO4 Battery

x 1

EG4 12000XP 12,000W 48V Split Phase Off-Grid Inverter

x 1

User Manual

x 1

Frequently Asked Questions

How do I connect this battery into my existing system?

These batteries use a standard M8 terminal. This battery can be connected directly to the onboard wiring system. You may also purchase additional cables from BigBattery.

How many times can I put this battery in parallel/series?

These batteries are not series capable but can be connected in parallel up to ten times. Make sure that the total amount of these batteries in your configuration never exceeds 15 total batteries. When connecting batteries in parallel, ensure all batteries are within 1 volt of one another.

How long will my battery last, and what do I do at the end of its life?

Lithium iron phosphate (LiFePO4) batteries can be cycled from 3500 - 5000 times. If you cycle the battery daily then you can get more than 12 years of use from your battery. When your battery is at the end of its lifespan, contact us and we'll recycle it for you, free of charge!

Product Documents:

BigBattery NEXUS 51.2V 15kWH LiFePO4 Battery User Manual

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BigBattery NEXUS 51.2V 15kWH LiFePO4 Battery Specification Sheet

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EG4 12000XP 12,000W 48V Split Phase Off-Grid Inverter Specification Sheet

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EG4 12000XP 12,000W 48V Split Phase Off-Grid Inverter User Manual

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EG4 12000XP 12,000W 48V Split Phase Off-Grid Inverter Certification Of Compliance

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