Big Battery 48V ETHOS 5.12kWh Stackable Battery Module
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Build Your Perfect Off-Grid Rig With Our System Calculator
Visit CalculatorThe BigBattery 48V ETHOS 5.12kWh Battery Module is the core of a scalable, stackable energy storage system—ideal for grid-tied homes, off-grid cabins, solar systems, and commercial setups. Each module features Tier 1 LiFePO4 cells (100Ah), a smart BMS with real-time monitoring, and is expandable up to 80kWh per system.
Engineered for safety and performance, it includes passive cell balancing, a fire-extinguishing module, and UL-certified ESS connectors. With a lifespan of 10+ years and 4,000–8,000 cycles at 80% DoD, it’s built to last.
The ETHOS system is IP65-rated, wall-mountable, and includes all necessary hardware for easy installation. Whether you're preparing for outages or building a complete solar setup, ETHOS delivers reliable, efficient power—on or off the grid.
Stackable Design – Expand your energy system with ease. The ETHOS allows you to stack multiple modules vertically for scalable power.
High-Capacity Storage – Each module delivers 5.12kWh of reliable energy—perfect for daily cycling, time-of-use offset, or emergency backup.
LiFePO4 Chemistry – Built with Lithium Iron Phosphate cells, known for their long cycle life, thermal stability, and safety.
Advanced BMS Built-In – Protects against overvoltage, short circuits, overcurrent, and temperature extremes for maximum system reliability.
UL Certified Safety – Includes UL1973 and UL9540A testing certifications, ensuring code compliance and peace of mind.
Modular Flexibility – Integrates with many 48V inverters, making it a great fit for custom and prebuilt energy systems.


Everything you need is included with your product.
| Category | Specifications |
| SKU | FETHS-48051-G1 |
| UPC | 850061252067 |
| System Voltage: | 48V |
| Nominal Voltage: | 51.2V |
| Chemistry: | LiFePO4 |
| kWh Capacity: | 5.12kWh |
| Ah Capacity: | 100Ah |
| 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 |
| Max Continuous Discharge Current: | 100A |
| Max Continuous Power: | 5120W |
| Max Discharge Peak Current: | 150A (Max 5 seconds) |
| Max Charge Current: | 100A |
| 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: | -4°F - 113°F (-20°C - 45°C) (Max 6 months) |
| Depth | 6.7 in (170 mm) |
| Width | 26.5 in (674 mm) |
| Height: | 16.5 in (419 mm) |
| Max Connections: | Up to (16) parallel connections per control box |
| Protection Rating: | IP65 |
| Communications: | CANBus / RS485 |
| Certifications | UL9540a, UL1973, & UN38.3 |
How many ETHOS batteries can I stack?
You can stack multiple modules based on your inverter’s configuration and your energy needs. For large systems, consult your installer to ensure proper BMS communication and power balancing.
Is this battery compatible with all 48V inverters?
It works with many major 48V inverter brands, but always confirm voltage, current, and communication protocol compatibility before integrating.
Does this battery support outdoor installation?
Yes. With its IP65 rating, the ETHOS is protected against dust and water spray, making it suitable for indoor or sheltered outdoor setups.
Is the BMS built-in or external?
Each module comes with an integrated Battery Management System that safeguards performance and extends battery life.
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