A Felicity Lithium Battery 12.5 kWh, 51.2 V is a high-capacity energy storage unit ideal for residential or small commercial solar backup systems. It uses lithium iron phosphate (LiFePOâ‚„) chemistry, giving high cycle life (often ~6000 cycles or more), good efficiency, built-in Battery Management System (BMS), over/under-voltage protection, and supports parallel expansion. The 51.2 V rating matches many 48 V inverters (nominal-voltage).