How to use the Battery Bank Size (Ah)
The Formula
Wh needed = watts × hours. Ah = Wh ÷ voltage. Example: 500 W for 8 h at 12 V needs about 333 Ah (before efficiency losses).
Practical Example
Multiply by 1.2–1.5 for inverter loss, aging, and temperature. For off-grid solar, start with the Solar Battery Bank calculator in Wh first.
About Battery Bank Size (Ah)
Ah sizing formula
Wh needed = watts × hours. Ah = Wh ÷ voltage. Example: 500 W for 8 h at 12 V needs about 333 Ah (before efficiency losses).
Add safety margin
Multiply by 1.2–1.5 for inverter loss, aging, and temperature. For off-grid solar, start with the Solar Battery Bank calculator in Wh first.