Big Battery | 12kW 20.4kWh ETHOS Off-Grid Power System
REVOLUTIONIZING OFF-GRID POWER! The 12kW 20.4kWh ETHOS Off-Grid Power System from BigBattery offers a robust and scalable energy solution for your tiny home, cabin, or homestead. Backed by industry-leading safety features and advanced technology, this system delivers dependable performance where it matters most.
Modular, Expandable, and Built to Last
The ETHOS is designed with a modular, stackable architecture for easy expansion and includes all necessary hardware for quick wall mounting. Its IP65-rated enclosure, internal fire suppression system, and high-efficiency BMS with automatic cell balancing provide long-term durability and peace of mind. The integrated control box features an interactive LED display and supports CANBus and RS485 communication for comprehensive power monitoring and system diagnostics.
Dual 6kW Inverters for Smart, Seamless Control
This kit comes with two 6000W EG4 split-phase inverter-chargers, each with a touchscreen LCD, dual MPPT inputs, and a built-in UPS for smooth transitions between grid and battery power. With support for PV arrays up to 8000W per inverter, smart load management, AC coupling, and peak shaving, these inverters empower you to optimize usage and lower monthly energy costs.
Energy Independence for Every Season
Whether you're preparing for outages, going fully off-grid, or seeking reliable year-round energy, the 12kW 20.4kWh ETHOS Off-Grid Power System ensures efficiency, safety, and total control over your power needs. Make the switch to energy independence—upgrade to ETHOS today.
What's Included
4 × 48V ETHOS 5.12kWh Stackable Battery Module
1 × ETHOS Control Box
1 × ETHOS RACK BASE
2 × EG4 6kW (8kPV) OFF-GRID INVERTER
1 × Ethos Parallel Comm Cable 4.9 ft (150cm)
1 × 2AWG (Black and Red) 3FT Ring to Ring Terminal Cable
2 × Ethos Parallel Power Cable 4.9 ft (1500mm)
Specs and Downloads
Single Stack Tech Specs
| 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 |
| 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: | UL9540A, UL1973, & UN38.3 |
Inverter Specs
AC INPUT & OUTPUT
| AC Voltage: | 120V AC / 240V AC |
| AC Frequency: | 50 Hz / 60 Hz |
| Max. Continuous AC Current: | 37.5A @ 240V |
| Max. AC Input Power: | 9000W |
| AC Bypass: | 50A |
| Output Voltage: | 120V AC / 240V AC |
| Output Frequency: | 50 Hz / 60 Hz |
| Max. Continuous Output Current: | 25A @ 240V |
| Output Power: | 6000W |
| Surge Capacity: | 12000W (3.5 sec) / 11000W (5 sec) |
| Power Factor: | 0.99 (Full Load) |
| Reactive Power Adjustment Range: | -0.8 - 0.8 Leading Adjustable |
| Total Harmonic Distortion: | <3% |
| Switching Time: | <15 ms (Single) / <30 ms (Parallel) |
PV INPUT
| No. of MPPTs (Inputs per MPPT): | 2 (1) |
| Max. Input Current: | 17A / 17A |
| Max. Short Circuit Input Current: | 25A / 25A |
| DC Input Voltage Range: | 100 - 480V DC |
| Start Up Voltage: | 100V DC ± 10V DC |
| MPPT Operating Voltage Range: | 120 - 385V DC |
| MPPT Voltage: | 320V DC |
| Max. PV Array Power: | 8000W (4000W per MPPT) |
| MPPT Efficiency: | 99% |
BATTERY
| Nominal Voltage: | 48V DC |
| Battery Voltage Range: | 46.4 - 60V DC |
| Max. Discharge Current: | 140A |
| Max. Charge Current: | 125A |
| DC Cut-Off Voltage: | 59V DC |
| DC Recovery Voltage: | 57.4V DC |
| Charge Cut-Off Voltage: | 58.4V DC |
OPERATING ENVIRONMENT & DIMENSIONS
| Operating Temperature: | 32ºF - 113ºF (0ºC - 45ºC) |
| Storage Temperature: | 5ºF - 140ºF (-15ºC - 60ºC) |
| Altitude: | <6,561 ft (2000 m) |
| Relative Humidity: | 5 - 95% |
| Typical Noise Emission: | <58 dB |
| Protection Rating: | IP20 |
| Max. Parallel Connections: | 16 |
| Weight: | 52.9 lbs (24 kg) |
| Depth: | 5.25 in (132 mm) |
| Width: | 18 in (457 mm) |
| Height: | 25.5 in (648 mm) |
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When Will My Order Ship?
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Do We Accept Returns?
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Are Products Brand New?
Yes! All products on Solar Guys Pro are 100% brand-new and in perfect condition.
We do not sell any used or refurbished items.
Orders over $500 include a FREE (Normally $149.99) 80-Page DIY Solar eBook — added automatically at checkout.
Frequently Asked Questions
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