Big Battery 6kW 15.3kWh ETHOS Off-Grid Power System - K0709
REVOLUTIONIZING OFF-GRID POWER! BigBattery’s 48V ETHOS systems are here, and this 15.36kWh configuration is the ideal solution for off-grid power in your tiny home, cabin, or homestead, supported by comprehensive safety, reliability, and state-of-the-art features.
The ETHOS System was built to be a versatile off-grid power solution, with a stackable, modular design for easy expandability, and all hardware included to mount your ETHOS to your wall with an effortless installation. The ETHOS comes equipped with an IP65-rated casing, an internal fire suppression system, as well as an advanced BMS with auto cell-balancing to ensure long-lasting safety and reliability. Plus, its control box features an interactive LED display, along with CANBus and RS485 communication protocols, so you can always monitor the status and performance of your power.
But that’s not all. We pair our ETHOS with a cutting-edge 6000W split-phase inverter & charger from EG4, which features its own LCD touch screen display, 2 MPPT inputs, an integrated UPS module for seamless on and off-grid switching, and the ability to handle PV arrays of up to 8000W. Plus, through its smart load control, AC coupling abilities, and peak shaving function, you can meet your power needs and protect your home against unstable grids or rolling blackouts, while seeing huge savings each month on your electric bill through peak shaving and time-of-use offsetting.
Whether you’re looking to ensure emergency backup power is always available, or you’re looking to outfit your home with a uninterrupted power system to last all season, or all year long, the ETHOS ensures reliable, efficient power delivery day in and day out, allowing you to save on utilities, and most importantly, stay powered and prepared. Take control of your power and shop the 48V ETHOS today!
Included
- 3 × 48V ETHOS 5.12kWh Stackable Battery Module
- 1 × ETHOS Control Box
- 1 × Product
- 1 × 15kWh Ethos Controller to Battery Power Cable 4ft (1220mm)
What our Experts Think
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All‑round off‑grid powerhouse — Combines a 12 kW inverter with a 20.4 kWh LiFePO₄ battery bank, giving enough capacity and output to run most household loads or a small off‑grid home reliably.
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Large energy storage with strong output — 20.4 kWh capacity provides extended runtime, while the 12 kW inverter output handles heavy loads (appliances, tools, HVAC), making it versatile for homes, cabins, or remote installations.
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Ready for real-world demands — Solid battery chemistry and robust BMS ensure deep‑cycle durability and stable power delivery, even under demanding or fluctuating load conditions.
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Simplifies system design — As a packaged solution, it reduces complexity, wiring, and compatibility issues — a convenient way to deploy a complete off‑grid power system with minimal configuration.
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Scalable & future‑proof — The system can be expanded or paired with solar, generators, or additional modules, allowing users to grow their setup as needs evolve.
Q&A
Q: What is the BigBattery 12 kW 20.4 kWh ETHOS Off‑Grid Power System (K0710)?
A: A complete off-grid system combining a 48 V lithium battery bank with a 12 kW inverter, designed for whole-home, cabin, or backup solar + storage power without relying on the grid.
Q: What does “20.4 kWh” refer to?
A: The total usable energy storage capacity of the battery bank, providing extended off-grid operation or reliable backup during outages.
Q: What are the key design and safety features?
A: LiFePO₄ chemistry, IP65-rated weather-resistant enclosure, advanced BMS with cell balancing, and an integrated internal fire-suppression system for safety and long-term reliability.
Q: What kind of inverter and capabilities are included?
A: A split-phase 12 kW inverter supporting household AC loads, solar PV input via MPPT, seamless switching between solar/battery and grid or generator power, and compatibility with large PV arrays.
Q: What types of users or setups is this system best for?
A: Tiny homes, cabins, off-grid residences, remote homesteads, backup-power installations, and other structures needing robust solar + battery storage.
Q: What are the main benefits compared with simpler battery setups or lead-acid systems?
A: Higher usable energy, maintenance-free operation, safer LiFePO₄ chemistry, longer lifespan, compact modular design, and integrated off-grid or backup functionality.
Q: Is the system scalable or modular?
A: Yes, additional ETHOS battery modules can be added to expand storage capacity and increase backup duration.
Maintenance Tips
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Install the ETHOS system in a cool, dry, and well-ventilated area to ensure optimal performance and prevent overheating.
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Regularly inspect all wiring, terminals, and connections for looseness, corrosion, or damage to maintain safe off-grid operation.
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Keep the system exterior clean and dust-free using a soft, dry cloth to avoid heat buildup.
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Avoid exposure to direct sunlight, moisture, and extreme temperatures to preserve internal components.
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Monitor battery state of charge and avoid deep discharges to maintain long-term capacity and efficiency.
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During extended periods of non-use, keep the system at 50–60% charge and disconnect from all loads and power sources.
