Here is the formula to help you choose the right inverter battery for your home: Step 1: Calculate Total Load Step 2: Size of Inverter: Size of Inverter = Total Load + (1+Af) / Ie VAStep 3: Size of Battery: Total Load of Battery Bank= (Total Load x Backup Capacity) / Battery Bank VoltStep 4: Connection of Battery: Series Connection:Selection of Battery for Voltage = Volt of Each Battery