Big Battery | 12kW 30.7kWh ETHOS Off-Grid Power System
REVOLUTIONIZING OFF-GRID POWER! The 12kW 30.7kWh ETHOS Off-Grid Power System from BigBattery is engineered to meet the energy demands of your tiny home, cabin, or homestead—offering premium safety, unmatched reliability, and powerful performance for all your off-grid needs.
Scalable, Durable, and Built for the Long Haul
Designed for flexibility, the ETHOS System features a modular, stackable design that allows for seamless expansion and straightforward wall mounting. Housed in an IP65-rated enclosure, each unit includes internal fire suppression and an advanced BMS with automatic cell balancing to ensure consistent performance and system longevity. The integrated control box features an interactive LED display and supports CANBus and RS485 communication protocols, making real-time power monitoring effortless.
Dual 6kW Inverters for Total Power Control
This system includes two 6000W EG4 split-phase inverter-chargers, each equipped with a touchscreen LCD, dual MPPT inputs, and an integrated UPS to ensure uninterrupted transitions between grid and battery power. Supporting up to 8000W of PV input each, these inverters also feature smart load control, AC coupling, and peak shaving capabilities—allowing you to significantly reduce energy costs through time-of-use optimization.
Off-Grid or On-Demand—Your Power, Your Way
Whether you need backup power, a full-time off-grid system, or a seasonal solution, the 12kW 30.7kWh ETHOS Off-Grid Power System gives you complete energy independence and peace of mind. Stay powered, stay prepared—take control of your energy future with ETHOS today.
What's Included
6 × 48V ETHOS 5.12kWh Stackable Battery Module
1 × ETHOS Control Box
1 × ETHOS RACK BASE
2 × EG4 6kW (8kPV) OFF-GRID INVERTER
1 × 2AWG (Black and Red) 3FT Ring to Ring Terminal Cable
2 × Ethos Parallel Power Cable 4.9 ft (1500mm)
1 × Ethos Parallel Comm Cable 4.9 ft (150cm)
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) |
Are Solar Guys Pro Authorized Retailers?
Yes! We are proud to be one of the few online retailers who are authorized retailers for every single product we carry!
When Will My Order Ship?
Most orders ship within 1–3 business days. You’ll get a tracking number as soon as it ships via email!
Do We Accept Returns?
Yes absolutely, we have a no-hassle, 30-day return policy on all items! To refer to the full policy, click HERE
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
Get your 30% Tax Solar Credit!
Unlock substantial savings with the government's Solar Tax Credit, which offers a robust 30% deduction on the installation costs of solar systems. This attractive incentive is your ticket to leveraging solar energy's eco-friendly potential while enjoying the financial benefits.
At Solar Guys Pro, our commitment is to you. Please be reminded that our expertise does not extend to tax advice. Nonetheless, our dedicated staff is eager to guide you through the process and ensure you capitalize on this exceptional offer.
Contact us now to learn more!