Fortress Power eFlex Max 5.4kWh Batteries (4) with DuraRack Enclosure

Start your journey to energy independence with this eFlex MAX and DuraRack bundle! Includes 4 eFlex MAX 5.4 kWh batteries and a DuraRack Enclosure to safely store your batteries.

The eFlex MAX 5.4 kWh is a high-performance 48V lithium iron phosphate (LFP) battery engineered for maximum flexibility, reliability, and long-term energy savings. Designed to operate in demanding environments — from homes and apartments to off-grid cabins, RVs, and boats — it delivers uninterrupted backup power with smart inverter integration and advanced system communications. With a guaranteed 8,000+ cycle life, a 10-year warranty, and built-in safety protections, the eFlex MAX meets the highest standards for quality and performance. Whether used for solar self-consumption, backup power, or off-grid storage, it’s a versatile solution built to last.

Expand your energy storage with the Fortress Power DuraRack. This iron enclosure stores up to 4 eFlex 5.4kWh batteries, and is expandable up to 4 units (15 eFlex batteries, 81KWh). The DuraRack includes integrated busbars and a DIN rail heater mount. This enclosure can be free-standing or pad mounted and is safe for indoor and outdoor installations.