Fortress eFlex Max 5.4 Lithium Battery

Price: $2,000

The Fortress eFlex Max 5.4 is a compact, expandable 48V lithium battery for residential solar and backup power systems. Ideal for off-grid or hybrid setups, it delivers high-efficiency storage and rugged performance in Hawaii’s demanding environment.

🔋 Battery Specifications:

• Voltage: 48V nominal
• Usable Capacity: 5.4 kWh
• Max Continuous Discharge: 120A
• Chemistry: Lithium Iron Phosphate (LFP)
• Mounting: Wall-mounted or floor/rack compatible
• Communication: CAN, RS485 – closed-loop capable
• Compatible with most major 48V inverters
• 10-year limited warranty

🚚 Statewide Hawaii Shipping:

• Local pickup in Hawaiian Paradise Park
• Big Island delivery available
• Ships to Maui, Kauai, Oahu, and all Hawaiian Islands

⚠️ Additional Notes:

• DIY product – no installation or permitting included
• All sales final – no returns
• Solarman can help with system design using this battery