Description
Description
BigBattery ETHOS + EG4 FlexBOSS18 ESS — 3-Phase Energy Storage System | LiFePO4 | UL Certified
The BigBattery ETHOS™ + EG4 FlexBOSS18 ESS is a complete, high-performance energy storage system engineered for both on-grid and off-grid applications. This 3-phase configuration pairs the scalable ETHOS 48V LiFePO4 battery system with three EG4 FlexBOSS18 hybrid inverters, delivering an intelligently integrated solution capable of handling serious residential and light commercial energy demands. Expandable to 80+ kWh, built to UL 9540 certified standards, and backed by lifetime U.S.-based technical support — this is backup power and energy independence done right.
- Complete ESS Solution — Battery and inverter system pre-configured to work seamlessly together out of the box
- 18,000W PV Input Per Inverter — High solar capacity with dual MPPT optimization on each FlexBOSS18 unit
- 3-Phase Output — Three FlexBOSS18 inverters deliver 120/240V split-phase power for flexible residential and light commercial load support
- LiFePO4 Battery Chemistry — Safe, stable lithium iron phosphate technology with 6,000+ cycle life
- Scalable to 80+ kWh — Modular ETHOS battery system supports future expansion as energy needs grow
- Closed-Loop Communication — CANBus/RS485 integration ensures optimized coordination between battery and inverter
- GridBOSS Integration Ready — Supports advanced load management, AC coupling, and generator integration via the EG4 GridBOSS MID gateway
- Advanced Safety Protections — Rapid shutdown, ground fault, and arc fault protection included
- Remote Monitoring & Alerts — Wi-Fi and 4G connectivity with real-time system tracking
- Maintenance-Free Operation — No routine servicing required
- IP65 / NEMA 4X Rated — Both battery and inverter carry robust weatherproof protection ratings
- Ships from Texas, USA — 12-year battery warranty | 10-year inverter warranty | Lifetime USA-based tech support
Specifications
BATTERY SPECIFICATIONS (per ETHOS module)
| Spec | Detail |
|---|---|
| GTIN-12 (U.P.C.) | 850061252005 |
| System Voltage | 48V |
| Nominal Voltage | 51.2V |
| Chemistry | LiFePO4 |
| kWh Capacity | 10.24 kWh |
| 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 | 10,240W |
| 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) |
| Dimensions (D × W × H) | 6.7 in × 26.5 in × 43.3 in (170 mm × 674 mm × 1100 mm) |
| Max Parallel Connections | Up to 16 per control box |
| Protection Rating | IP65 / NEMA 4X |
| Communications | CANBus / RS485 |
| Certifications | UL9540, UL9540A, UL1973, UN38.3 |
INVERTER SPECIFICATIONS (per EG4 FlexBOSS18 unit)
| Spec | Detail |
|---|---|
| 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 | 13,000W |
| Max. AC Bypass | 90A |
| Operating Voltage Range | 180 – 270VAC |
| Output Voltage | 120/240VAC | 120/208VAC |
| Max. Output Current | 66.7A |
| Nominal Output Power (without PV) | 12,000W @ 240V | 12,000W @ 208V |
| Nominal Output Power (with PV) | 16,000W @ 240V | 13,800W @ 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 Power | 12,000W @ 240VAC | 12,000W @ 208VAC |
| Peak Power | 20,000W (0.5 sec) | 15,000W (1 sec) | 12,500W (6 min) | 11,000W (12 min) |
| Number 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. Recommended PV Input | 18,000W |
| Max. Efficiency | 97.5% (PV to Grid) | 94.5% (PV to Battery) | 94% (Battery to Grid) |
| Idle Consumption | <65W |
| Battery Nominal Voltage | 48VDC |
| Battery Voltage Range | 40 – 60VDC |
| Max. Charge / Discharge Power | 10,000W |
| Recommended Battery Capacity per Inverter | >300Ah |
| Operating / Storage Temperature Range | -13°F – 140°F (-25°C – 60°C) |
| Operating Altitude | <6,561 ft (2,000 m) |
| Relative Humidity | 0 – 100% |
| Typical Noise Emission | <50dB @ 3 ft |
| Design Topology | High-Frequency / Transformerless |
| Protection Rating | IP65 / NEMA 4X |
| Communications | RS485 / CANBus / Wi-Fi / 4G |
| Max. Parallel Connections | 10 |
| Weight | 115 lbs (52 kg) |
| Dimensions (D × W × H) | 11.2 in × 22.8 in × 30.5 in (287 mm × 567 mm × 775 mm) |
| Certifications | UL1741 |
FAQs
Q: Is this system compatible with both on-grid and off-grid setups? A: Yes. The ETHOS + EG4 FlexBOSS18 ESS is designed for both on-grid and off-grid applications, and supports grid-tied, hybrid, and off-grid installations.
Q: Can I expand the battery capacity of this system in the future? A: Yes. The ETHOS battery system is modular and scalable up to 80+ kWh, allowing you to add additional ETHOS modules as your energy storage needs grow.
Q: What certifications does this energy storage system carry? A: The ETHOS battery holds UL9540, UL9540A, UL1973, and UN38.3 certifications. The EG4 FlexBOSS18 inverter is UL1741 certified. The combined system also has a CEC Listing.
Q: How long is the warranty on this system? A: The ETHOS battery carries a 12-year warranty and the EG4 FlexBOSS18 inverter carries a 10-year warranty. Lifetime USA-based technical support is also included.
Q: Does this system support remote monitoring? A: Yes. The EG4 FlexBOSS18 inverter includes Wi-Fi and 4G connectivity for real-time monitoring and alerts.
