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6x ETHOS + EG4 FLEXBOSS21 ESS Off-Grid System

6x ETHOS + EG4 FLEXBOSS21 ESS Off-Grid System

SKU: K0244

Price: $12,045.00
List Price: $12,645.00
Price: $12,045.00
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Product Summary:

The BigBattery ETHOS + EG4 FlexBOSS21 system pairs modular, UL-certified 48V lithium storage with a next-generation hybrid inverter for a complete, future-ready energy solution. ETHOS provides scalable capacity, intelligent management, and a 12-year warranty for long-lasting, maintenance-free energy independence, while FlexBOSS21delivers 12kW output and up to 21,000W of PV input with 3 MPPTs, 90A grid feed-through at 120/240VAC, and seamless integration with the EG4 GridBOSS MID gateway for smart load management, AC coupling, and generator support. With built-in rapid shutdown, ground fault and arc fault protection, plus Wi-Fi monitoring and mobile alerts, this combo offers safe, efficient, and highly flexible power for modern on-grid or off-grid residential and commercial systems.

Items IncludedSKU

BigBattery ETHOS | 48V - 5.1kWh | UL1973 | Home Battery Backup LFP
6xBigBattery ETHOS | 48V - 5.1kWh | UL1973 | Home Battery Backup LFPFETHS-48051-G1
ETHOS Control Box
1xETHOS Control BoxCNT060
EG4 FlexBOSS21 Hybrid Solar Inverter | 21kW PV / 16kW AC | Split-Phase | 4-MPPT | Scalable | Remote Wi-Fi Monitoring
1xEG4 FlexBOSS21 Hybrid Solar Inverter | 21kW PV / 16kW AC | Split-Phase | 4-MPPT | Scalable | Remote Wi-Fi MonitoringINV027
ETHOS Stack to Stack Power Cable Pair (4.9 ft)
2xETHOS Stack to Stack Power Cable Pair (4.9 ft)CBL089
ETHOS Stack to Stack Comm Cable (4.9 ft)
1xETHOS Stack to Stack Comm Cable (4.9 ft)CBL096
ETHOS RACK BASE
1xETHOS RACK BASECNT081
ETHOS Battery Top Plate Cover — Side Panel Protection Accessory
1xETHOS Battery Top Plate Cover — Side Panel Protection AccessoryCNT139

Battery Downloads

SKU#:K0241, K0242, K0243, K0244, K0245, K0246, K0247, K0248, K0249, K0250, K0251
Spec Sheet:DownloadDOWNLOAD
User Manual:DownloadDOWNLOAD
UL9540 Certificate – BigBattery ETHOS + EG4 FlexBOSS21:DownloadDOWNLOAD
UL9540A Certificate:DownloadDOWNLOAD
UL1973 Certificate:DownloadDOWNLOAD
UN38.3 Certificate:DownloadDOWNLOAD
Safety Data Sheet:DownloadDOWNLOAD
CEC Listing – BigBattery ETHOS + EG4 FlexBOSS21:Go to linkGO TO LINK

Battery Specifications

GTIN-12 (U.P.C.):850061252005
System Voltage:48V
Nominal Voltage:51.2V
Chemistry:LiFePO4
kWh Capacity:10.24kWh
Ah Capacity:200Ah
Charging Voltage Range:55.6 – 57V
Max Charge Voltage:57V
Operating Voltage Range:48 – 57V
Suggested Low Voltage Cutoff:48 – 50.8V
BMS Cutoff Range:42 – 47V
Cell Configuration:16S 2P
Max Continuous Discharge Current:200A
Max Continuous Power:10240W
Max Discharge Peak Current:300A (Max 5 seconds)
Max Charge Current:200A
Charge Temperature Range:32°F – 113°F (0°C – 45°C)
Discharge Temperature Range:-4°F – 140°F (-20°C – 60°C)
Optimal Discharge Temperature Range:59°F – 95°F (15°C – 35°C)
Storage Temperature Range (SoC >50%):-4°F – 113°F (-20°C – 45°C)(Max 6 months)
Weight:273 lb (123.8 kg)
Depth:6.7 in (170 mm)
Width:26.5 in (674 mm)
Height:43.3 in (1100 mm)
Max Connections:Up to (16) parallel connections per control box
Protection Rating:IP65 / NEMA 4X
Communications:CANBus / RS485
Certifications:UL9540, UL9540A, UL1973, & UN38.3

Inverter Downloads

SKU#:K0241, K0242, K0243, K0244, K0245, K0246, K0247, K0248, K0249, K0250, K0251
Spec Sheet:DownloadDOWNLOAD
User Manual:DownloadDOWNLOAD
UL1741 Certificate:DownloadDOWNLOAD
CEC Listing – BigBattery ETHOS + EG4 FlexBOSS21: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:50A @ 240V | 57.7A @ 208V
Max. AC Input Power:12000W
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:24000W (0.5 sec) | 18000W (1 sec)
15000W (6 min) | 13200W (12 min)
Operating Frequency:60 Hz (Default) | 50 Hz
Total Harmonic Distortion Voltage:<5%
Transfer Time:20ms (Default) | 10ms (Configurable) | 20ms (Parallel)
No. of MPPTs:3
Inputs per MPPT:2 (MPPT 1) | 2 (MPPT 2) | 1 (MPPT 3)
Max. Usable Input Current:26A (MPPT 1) | 26A (MPPT 2) | 15A (MPPT 3)
Max. Short Circuit Input Current:31A (MPPT 1) | 31A (MPPT 2) | 19A (MPPT 3)
DC Input Voltage Range:100 – 600VDC
Unit Start-Up Voltage:100VDC
MPPT Operating Voltage Range:120 – 440VDC
Nominal MPPT Voltage:360VDC
Max. Utilized PV Array Power:21000W
Max. Recommended PV Input:25000W
Max. Efficiency:97% (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:12000W
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
Max. Parallel Connections:16
Weight:88 lbs (40 kg)
Depth:11.3 in (287 mm)
Width:22.3 in (567 mm)
Height:30.5 in (775 mm)