Product Summary:

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.

Nexus + EG4 12000XP

$5,630.00

SKU# K0154

Battery Selected

1× BigBattery NEXUS

Total Capacity

15 kWh

Inverter Selected

1× EG4 12000XP

Input / Output

18 kW / 12 kW

Choose Your Inverter Option*

EG4 12kPV EG4 18kPV EG4 FlexBoss18 EG4 FlexBoss21 None

Choose Your Battery Option*

BigBattery ETHOS EG4 280Ah All Weather EG4 280Ah Indoor EG4 314Ah Indoor None

Choose Your Inverter Option*

APEX-6.5K APEX-10K EG4 6000XP EG4 12000XP VICTRON MP II 3000 VICTRON MP II 5000 None

Choose Your Battery Option*

BigBattery NEXUS BigBattery ETHOS BigBattery HUSKY2 INV EG4 280Ah All Weather EG4 280Ah Indoor EG4 314Ah All Weather EG4 314Ah Indoor None

Choose Your ESS Configuration*

SKU: K0154-V Category: Off-Grid

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Introducing the Nexus

Sleek & Compact Design

Our stackable, compact design comes with all the hardware you need for a straightforward setup, letting you get your off-grid system up and running efficiently in less time. Engineered for reliability in any off-grid environment, it delivers consistent power when you need it most.

Off-Grid Energy Reliability

With 300Ah of capacity, 100A continuous discharge, and peak support up to 110A, NEXUS handles high-demand loads with ease. NEXUS’s smart thermal management enables charging from 32 °F to 113 °F and discharging down to -4 °F, making it a true all-weather energy solution.

Modular ESS That Grows With You

NEXUS supports parallel expansion up to 15 units, offering 225kWh total capacity per inverter. With RS485, CAN, and RJ45 communication ports, it’s ready to integrate seamlessly into new or existing inverter systems—ensuring full system transparency, automation, and control.

Legacy Product Parallel Compatibility

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

Battery Downloads

SKU#:K0154, K0155, K0156, K0160, K0161, K0162, K0163

Spec Sheet:

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User Manual:

DOWNLOAD

Battery Specifications

Battery Specifications:NEXUS 15KWh

System Voltage:48V

Nominal Voltage:51.2V

Chemistry:LiFePO4

Usable Energy (kWh):15kWh

Ah Capacity:300Ah

Cell Configuration:16S1P

Max Continuous Discharge:140A

Max Discharge Power:7.6kW

Max Discharge Peak Current:270A(1s)

Max Charge Current:140A

Charging Voltage Range:53.5V-57.6V

Operating Voltage Range:48V-57.6V

Max Charge Voltage:57.9V

Suggested Low Voltage Cutoff50.8V

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%):(1 month:-4°F ~ 113°F | 3 months: -4°F ~ 95°F | 6 months: -4°F ~ 77°F)

Humidity Range:10%-95% (No Condensation)

Weight (lbs):~315 lbs

Dimensions (WxHxD):19.7 x 27.5 x 15.7 in (500×700×400 mm)

Altitude Limit:<2000m

Max Connections:15 in parallel (up to 225kWh)

Communications:RS485 / RJ45 / CAN

Protection Rating:IP21

Installation:Indoor Floor-standing

Inverter Downloads

SKU:K0154, K0155, K0156, K0160, K0161, K0162, K0163

Spec Sheet:

User Manual:

UL1741 Certificate:

UL9540 Certificate:

WiFi Configuration Guide:

DOWNLOAD

CEC Listing – EG4 12000XP:

GO TO LINK

Inverter Specifications

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

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)

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)

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

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

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:5 – 95% (Non-Condensing)

Typical Noise Emission:<60 dB

Cooling Method:Fan

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)

BigBattery batteries are backed by a 12-year warranty, giving you reliable long-term performance and confidence in every charge. Designed for durability and engineered to last, our batteries are built to power your setup for over a decade. For more information, please visit our policy page