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EG4 48V WallMount Indoor LiFePO4 Battery (14.3kWh-57.3kWh) + FlexBoss18 13kW 48V Split Phase AC Hybrid Inverter
by EG4

EG4 48V WallMount Indoor LiFePO4 Battery (14.3kWh-57.3kWh) + FlexBoss18 13kW 48V Split Phase AC Hybrid Inverter

SKU: K0108
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$8,648.74
$8,648.74 - $26,466.16
$8,648.74
$6,918.99
$6,918.99 - $21,172.93
$6,918.99
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Bundle Options: 1 x Indoor Battery + FlexBoss18 13kW Inverter

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Off Grid Stores is an authorized retailer of EG4 products. Because of this, we pass on EG4's manufacturer warranty to you.

Product Highlights

Suitable For

  • RESIDENTIAL POWER SYSTEMS
  • HOME SOLAR SYSTEMS
  • CABINS & TINY HOMES
  • FAMILY HOMES & MANSIONS
  • OFF-GRID HOMESTEADS
  • EMERGENCY POWER
  • WHOLE HOME BACKUP
  • COMMERCIAL SYSTEMS
  • WHOLE OFFICE BACKUP
  • LEAD ACID REPLACEMENT

Features

  • WALL-MOUNTABLE DESIGN
  • AUTOMATIC SELF-HEATING
  • TOUCH SCREEN LCD DISPLAY
  • PASSIVE CELL BALANCING
  • INTEGRATED 600A BUSBARS
  • DUAL INTERNAL FIRE ARRESTORS
  • EMERGENCY DISCONNECT FUNCTION
  • ZERO MAINTENANCE REQUIRED
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EG4 48V WallMount Indoor LiFePO4 Battery (14.3kWh-57.3kWh) + FlexBoss18 13kW 48V Split Phase AC Hybrid Inverter

EG4 48V WallMount Indoor LiFePO4 Battery (14.3kWh-57.3kWh) + FlexBoss18 13kW 48V Split Phase AC Hybrid Inverter

Introducing the high-performance EG4 ESS WallMount-FLEXBOSS18, a compact yet powerful energy storage system designed to deliver reliable backup and solar energy integration for homes and small businesses. With a sleek wall-mounted design, advanced safety features, and UL certifications, this 14.3kWh kit is your gateway to long-term energy savings and greater energy independence.

At the heart of this system is the 48V 14.3kWh EG4 WallMount Indoor Battery, built with the safest LiFePO4 chemistry and rated for over 8,000 cycles at 80% depth of discharge—offering a total of 82.6MWh of lifetime energy production. Housed in a durable IP20-rated enclosure, the battery includes a smart BMS that actively monitors voltage, current, and temperature in real time, ensuring safe, optimized operation. It also features passive cell balancing, an automatic self-heating function for colder climates, and dual internal fire extinguishers. For added safety, an emergency stop function allows you to shut down the entire system instantly in case of emergency. An LCD touchscreen display is conveniently located on the side of the unit, giving you real-time insights into your energy usage and battery performance.

Powering the system is the EG4 FLEXBOSS18 hybrid inverter, capable of delivering 13kVA of output power and handling PV arrays of up to 18,000W through its 3 MPPT channels. The inverter includes an integrated UPS module for seamless on/off-grid transitions, as well as an Automatic Transfer Switch (ATS), backup mode, and peak shaving to reduce demand charges and improve energy efficiency. Whether you’re powering through outages or maximizing your solar investment, this inverter delivers smooth, intelligent energy management.

Certified under UL9540, UL9540A, and UL1973 standards, and backed by a 12-year warranty on the battery, the EG4 ESS WallMount-FLEXBOSS18 14.3kWh 13kVA kit is a compact, reliable, and future-ready solution for those looking to take control of their energy needs with confidence.

Specifications:

EG4 48V 14.3kWh WallMount Indoor Battery
System Voltage 48V
Nominal Voltage 51.2V
Chemistry LiFePO4
kWh Capacity 14.3kWh
Ah Capacity 280Ah
BMS Charging Voltage (Bulk/Absorb) 56V (±0.8V)
Rec. Charging Voltage (Bulk/Absorb) 56.2V (±0.2V)
Rec. Float Setting 54V (±0.2V)
Rec. SoC Cutoff Setting 20%
Max. Continuous Charge/Discharge Current 200A
Rec. Charge Current 60 – 160A
Rec. Discharge Current 160A
Max Continuous Discharge Rate 10240W
HEATER
Voltage 56V
Power Consumption 224W
Internal Temperature Cutoffs ≤32ºF (On) | ≥41ºF (Off)
OPERATING ENVIRONMENT
Charging Temperature Range 32ºF – 113ºF
Discharging Temperature Range -4ºF – 122ºF
Storage Temperature Range -4ºF – 122ºF
Protection Rating IP20
Communications RS485 | CANBus
DIMENSIONS
Weight 282.2 lbs
Depth 9.6 in
Width 18.1 in
Height 36.4 in
EG4 FlexBOSS18 13kW 48V Split Phase AC Hybrid Inverter
AC INPUT
Nominal AC Voltage 120/240VAC | 120/208VAC
(L1/L2/N required)
Frequency 60 Hz (Default) | 50 Hz
Max. AC Current 54A @ 240V | 54A @ 208V
Max. AC Input Power 13000W
Max. AC Bypass 90A
AC GRID OUTPUT
Operating Voltage Range 180 – 270VAC
Output Voltage 120/240VAC | 120/208VAC
(L1/L2/N required)
Max. Output Current 66.7A
Output Frequency 60 Hz (Default) | 50 Hz
Nominal Output Power (without PV) 12000W @ 240V | 12000W @ 208V
Nominal Output Power (with PV) 16000W @ 240V | 13800kW @ 208V
Power Factor 0.99 (Full Load)
Reactive Power Adjustment Range -0.8 – 0.8 Leading Adjustable
Total Harmonic Distortion <5% (Full Load)
Transfer Time 20ms (Default) | 10ms
(Configurable) | 20ms (Parallel)
AC BACKUP / UPS OUTPUT
Rated Output Current 50A @ 240V | 57.7A @ 208V
Nominal Output Voltage 120/240VAC | 120/208VAC
Rated Output Power 12000W @ 240VAC | 12000W @ 208VAC
Peak Power 20000W (0.5 sec) | 15000W (1 sec)
12500W (6 min) | 11000W (12 min)
Operating Frequency 60 Hz (Default) | 50 Hz
Total Harmonic Distortion Voltage <5%
Transfer Time 20ms (Default) | 10ms
(Configurable) | 20ms (Parallel)
PV INPUT
No. of MPPTs 2
Inputs per MPPT 2 (MPPT 1) | 2 (MPPT 2)
Max. Usable Input Current 26A (MPPT 1) | 26A (MPPT 2)
Max. Short Circuit Input Current 31A (MPPT 1) | 31A (MPPT 2)
DC Input Voltage Range 100 – 600VDC
Unit Start-Up Voltage 200VDC
MPPT Operating Voltage Range 120 – 440VDC
Nominal MPPT Voltage 360VDC
Max. Utilized PV Array Power:18 18000W
Max. Recommended PV Input 18000W
Max. Efficiency 97.5% (PV to Grid) | 94.5% (PV to Battery)
| 94% (Battery to Grid)
Idle Consumption <65W
BATTERY
Nominal Voltage 48VDC
Voltage Range 40 – 60VDC
Max. Charge / Discharge Power 10000W
Recommended Battery
Capacity per Inverter		 >300Ah
OPERATING ENVIRONMENT
Operating / Storage Temperature
Range		 -13ºF – 140ºF (-25ºC – 60ºC)
Operating Altitude <6,561 ft (2000 m)
Relative Humidity 0 – 100%
Typical Noise Emission <50dB @ 3 ft
Design Topology High-Frequency / Transformerless
Protection Rating IP65 / NEMA 4X
Communications RS485 / CANBus / WiFi / 4G
Max. Parallel Connections 10
DIMENSIONS
Weight 115 lbs
Depth 11.2 in
Width 22.8 in
Height 30.5 in

PACKAGE INCLUDES

EG4 48V 14.3kWh WallMount Indoor LiFePO4 Battery + FlexBoss18 13kW (18kPV) Hybrid Inverter

EG4 48V 14.3kWh WallMount Indoor Battery

x 1

Mounting Bracket

x 1

Concrete Expansion Bolts

x 6

Red & Black Battery to Inverter Power Cables (3.3 FT)

x 2

Battery to Inverter Comm Cable (5 FT)

x 1

EG4 Indoor Buildable Conduit Box

x 1

EG4 FlexBOSS18 13kW 48V Split Phase AC Hybrid Inverter

x 1

Product Documents:

EG4 48V 14.3kWh WallMount Indoor Battery User Manual

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EG4 48V 14.3kWh WallMount Indoor Battery User Manual

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EG4 13kW 48V Split Phase AC Hybrid Inverter User Manual

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EG4 FlexBOSS18 13kW 48V Split Phase AC Hybrid Inverter Specification Sheet

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EG4 FlexBOSS18 13kW 48V Split Phase AC Hybrid Inverter Certification Of Compliance

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