eForce 28.8kWh Stackable Whole-Home Energy Storage System

The Fortress Power eForce 28.8 kWh is a modular, stackable Lithium Iron Phosphate (LFP) battery system designed for whole-home backup and off-grid reliability. Composed of three 9.6 kWh modules stacked vertically, this IP65-rated system features a cable-free design for quick installation and built-in heating for performance in extreme temperatures. It integrates seamlessly with Sol-Ark and Fortress Envy inverters for a robust, scalable energy storage solution.

Product Specifications

• Voltage Range: 39V – 54V

• Max Continuous Current: 250 A (Charge/Discharge)

• Surge Power: 28.8 kW (10 seconds)

• Round Trip Efficiency: > 98%

• Communication: CAN / RS485 / Wi-Fi

• Cycle Life: 8,000 Cycles (@ 80% DoD)

Why Choose eForce 28.8 kWh

The eForce 28.8 is the ideal solution for homeowners who need high capacity without the clutter of messy wiring. Its innovative “LEGO-style” stacking design eliminates external battery cables between modules, reducing installation time and failure points. With an IP65 weatherproof rating and integrated heating, it is one of the few batteries that can be safely installed outdoors in harsh climates, freeing up valuable garage or utility room space.

Benefits of eForce 28.8 kWh

• Cable-Free Stacking: Modules connect via wireless quick-connect plugs, allowing for a clean, professional install without the danger and mess of external jumper cables.

• All-Weather Performance: Built-in temperature sensors and heating elements ensure the battery charges and discharges reliably even in freezing temperatures (down to -4°F), unlike standard lithium batteries that shut down in the cold.

• Massive Power Output: The 28.8 kWh stack supports continuous discharge rates high enough to power heavy loads like pumps and HVAC systems when paired with a capable inverter.

• Smart Management: The included “eWay” top unit acts as a BMS and combiner box, offering closed-loop communication with Sol-Ark, Victron, and Fortress inverters for precise state-of-charge monitoring.

General Data

• Dimensions (W x D x H): 30.89 x 9.08 x 73.13 in (784 x 231 x 1857 mm)

• Weight: 705 lbs (320 kg)

• Mounting: Floor Standing (includes base)

• Operating Temperature: -4°F to 140°F (-20°C to 60°C)

• Certifications: UL 1973, UL 9540, UL 9540A, UN 38.3