ETHOS + EG4 FLEXBOSS18 ESS
ETHOS + EG4 FLEXBOSS18 ESS - Image 2
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Product Summary:

The BigBattery ETHOS + EG4 FlexBOSS18 system combines modular, UL-certified 48V lithium storage with a powerful hybrid inverter for a complete home or small commercial energy solution. ETHOS delivers scalable capacity, intelligent management, and a 12-year warranty for long-lasting, maintenance-free energy independence, while FlexBOSS18 provides up to 18,000W PV input, dual MPPTs, and 90A grid feed-through at 120/240VAC for flexible design and strong grid-tied performance. Integrated with the GridBOSS MID gateway, it supports smart load management, AC coupling, and generator input, with built-in rapid shutdown, ground fault, and arc fault protection plus Wi-Fi monitoring and mobile alerts for safe, efficient, and future-ready power.

ETHOS + EG4 FLEXBOSS18 ESS

$6,575.00
SKU# K0230

Battery Selected

2× 48V ETHOS

Total Capacity

10.24 kWh

Inverter Selected

1× EG4 FlexBoss18

Input / Output

18 kW / 13 kW

Choose Your Inverter Option*

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*

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

Choose Your ESS Configuration*

1x Inverter

Standard

2x Inverter

Large

3x Inverter

3 Phase

SKU: K0230-V Category:
Quantity:

Battery Downloads

SKU#:K0230, K0231, K0232, K0233, K0234, K0235, K0236, K0237, K0238, K0239, K0240
Spec Sheet:DownloadDOWNLOAD
User Manual:DownloadDOWNLOAD
UL9540 Certificate – BigBattery ETHOS + EG4 FlexBOSS18:DownloadDOWNLOAD
UL9540A Certificate:DownloadDOWNLOAD
UL1973 Certificate:DownloadDOWNLOAD
UN38.3 Certificate:DownloadDOWNLOAD
Safety Data Sheet:DownloadDOWNLOAD
CEC Listing – BigBattery ETHOS + EG4 FlexBOSS18: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#:K0230, K0231, K0232, K0233, K0234, K0235, K0236, K0237, K0238, K0239, K0240
Spec Sheet:DownloadDOWNLOAD
User Manual:DownloadDOWNLOAD
UL1741 Certificate:DownloadDOWNLOAD
CEC Listing – BigBattery ETHOS + 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)
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