Product Summary:

The EG4 280Ah Indoor Battery + EG4 FlexBOSS18 ESS System is a powerful, scalable energy solution designed for both on-grid and off-grid applications. Combining the 14.3kWh EG4 WallMount Indoor LiFePO₄ battery with the high-performance FlexBOSS18 hybrid inverter, this system delivers reliable, efficient, and intelligent energy management for residential and commercial use.

 

The FlexBOSS18 provides up to 18,000W PV input with dual MPPTs and 120/240V split-phase output, enabling flexible system design and strong performance. Paired with the indoor WallMount battery – featuring UL-certified LiFePO₄ storage, 8,000+ cycle life, advanced BMS protection, self-heating, and emergency stop capability – this system ensures safe, long-lasting operation.

 

Designed with UL 9540 certified configurations, advanced battery management, and U.S.-engineered components, this system ensures safe, maintenance-free performance with seamless closed-loop communication and real-time monitoring.

Ships From: Texas, USA
Warranty: 10 Years (Battery), 10 Years (Inverter)
Support: Lifetime USA-Based Tech Support

 

Compatibility

Integrated & Optimized System:

  • EG4 280Ah Indoor Battery + EG4 FlexBOSS18 Hybrid Inverter

Expandable & Flexible:

  • Add additional batteries for increased storage capacity
  • Supports grid-tied, hybrid, and off-grid installations
  • Compatible with solar + generator input configurations
Key Features
  • Complete ESS Solution – Battery + inverter system designed to work seamlessly together
  • 18,000W PV Input – High solar capacity with dual MPPT optimization
  • 120/240V Split-Phase Output – Reliable power for residential and commercial loads
  • 14.3kWh LiFePO₄ Battery – Safe, UL-certified indoor energy storage
  • 8,000+ Cycle Life – Long-lasting performance at 80% DoD
  • Advanced BMS & Safety Features – Includes real-time monitoring, self-heating, and E-Stop
  • GridBOSS Integration – Advanced load management, AC coupling, and generator support
  • Closed-Loop Communication – Seamless coordination between battery and inverter
  • Advanced Safety Protections – Includes rapid shutdown, ground fault, and arc fault protection
  • Remote Monitoring & Alerts – Real-time system tracking and performance insights
  • Wall-Mount Indoor Design – Clean, space-saving installation
  • Maintenance-Free Operation – No routine servicing required

A scalable, high-performance energy storage system built for flexibility, safety, and long-term energy independence.

Simple System Expansion
EG4 FlexBoss18 + Indoor ESS
EG4 FlexBoss18 + Indoor ESS
Power that never sleeps at night
UL Certified
EG4 Indoor Features
GridBoss

.

See More On YouTube

 

 

Battery Downloads

SKU#:K0108
Spec Sheet:DownloadDOWNLOAD
Quick Start Guide:DownloadDOWNLOAD
UL9540A Certificate:DownloadDOWNLOAD
UL1973 Certificate:DownloadDOWNLOAD
Connection Guide:DownloadDOWNLOAD
Monitoring & Settings Guide:DownloadDOWNLOAD
Maintenance Guide:DownloadDOWNLOAD
Firmware Update Guide:DownloadDOWNLOAD
CEC Listing- EG4 WallMount Indoor:Go to linkGO TO LINK

Battery Specifications

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
Voltage:56V
Power Consumption:224W
Internal Temperature Cutoffs:≤32ºF (On) | ≥41ºF (Off)
Charging Temperature Range:32ºF – 113ºF (0ºC – 45ºC)
Discharging Temperature Range:-4ºF – 122ºF (-20ºC – 50ºC)
Storage Temperature Range:-4ºF – 122ºF (-20ºC – 50ºC)
Protection Rating:IP20
Communications:RS485 | CANBus
Weight:282.2 lbs (128 kg)
Depth:9.6 in (245 mm)
Width:18.1 in (460 mm)
Height:36.4 in (925 mm)

Inverter Downloads

SKU#:K0108
Spec Sheet:DownloadDOWNLOAD
User Manual:DownloadDOWNLOAD
UL1741 Certificate:DownloadDOWNLOAD
CEC Listing- EG4 FlexBoss18:Go to linkGO TO LINK

Inverter Specifications

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
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)
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%
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:1818000W
Max. Recommended PV Input:18000W
Max. Efficiency:97.5% (PV to Grid) | 94.5% (PV to Battery) | 94% (Battery to Grid)
Idle Consumption:<65W
Nominal Voltage:48VDC
Voltage Range:40 – 60VDC
Max. Charge / Discharge Power:10000W
Recommended Battery Capacity per Inverter:>300Ah
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
Weight:115 lbs (52 kg)
Depth:11.2 in (287 mm)
Width:22.8 in (567 mm)
Height:30.5 in (775 mm)

Compare Battery & Inverter

FlexBoss18 Inverter: 10-Year EG4 Manufacturer Warranty
WallMount Indoor Battery: 10-Year EG4 Manufacturer Warranty

Simple System Expansion
EG4 FlexBoss18 + Indoor ESS
EG4 FlexBoss18 + Indoor ESS
Power that never sleeps at night
UL Certified
EG4 Indoor Features
GridBoss

.

See More On YouTube

 

 

Battery Downloads

SKU#:K0108
Spec Sheet:DownloadDOWNLOAD
Quick Start Guide:DownloadDOWNLOAD
UL9540A Certificate:DownloadDOWNLOAD
UL1973 Certificate:DownloadDOWNLOAD
Connection Guide:DownloadDOWNLOAD
Monitoring & Settings Guide:DownloadDOWNLOAD
Maintenance Guide:DownloadDOWNLOAD
Firmware Update Guide:DownloadDOWNLOAD
CEC Listing- EG4 WallMount Indoor:Go to linkGO TO LINK

Battery Specifications

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
Voltage:56V
Power Consumption:224W
Internal Temperature Cutoffs:≤32ºF (On) | ≥41ºF (Off)
Charging Temperature Range:32ºF – 113ºF (0ºC – 45ºC)
Discharging Temperature Range:-4ºF – 122ºF (-20ºC – 50ºC)
Storage Temperature Range:-4ºF – 122ºF (-20ºC – 50ºC)
Protection Rating:IP20
Communications:RS485 | CANBus
Weight:282.2 lbs (128 kg)
Depth:9.6 in (245 mm)
Width:18.1 in (460 mm)
Height:36.4 in (925 mm)

Inverter Downloads

SKU#:K0108
Spec Sheet:DownloadDOWNLOAD
User Manual:DownloadDOWNLOAD
UL1741 Certificate:DownloadDOWNLOAD
CEC Listing- EG4 FlexBoss18:Go to linkGO TO LINK

Inverter Specifications

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
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)
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%
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:1818000W
Max. Recommended PV Input:18000W
Max. Efficiency:97.5% (PV to Grid) | 94.5% (PV to Battery) | 94% (Battery to Grid)
Idle Consumption:<65W
Nominal Voltage:48VDC
Voltage Range:40 – 60VDC
Max. Charge / Discharge Power:10000W
Recommended Battery Capacity per Inverter:>300Ah
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
Weight:115 lbs (52 kg)
Depth:11.2 in (287 mm)
Width:22.8 in (567 mm)
Height:30.5 in (775 mm)

Compare Battery & Inverter

FlexBoss18 Inverter: 10-Year EG4 Manufacturer Warranty
WallMount Indoor Battery: 10-Year EG4 Manufacturer Warranty

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