3,840Wh LiFePO₄ Batteries for Enhanced Safety and 6,500+ Life Cycles. Compatible with F3600 Pro for a maximum of 11,520Wh capacity. (F3600 Pro+2*FB3840) Features with a 100W USB-C and a 18W USB-A ports ,you can use the FB3840 as a portable power station. The FB3840 expansion battery enables it to recharge quickly through solar power at a 200W maximum loading scale. Intelligent Battery Management System (BMS) 5-Year Hassle-Free Warranty