Convert battery amp-hours to watt-hours at any system voltage (12 V RV, 24 V, 48 V solar). Wh = Ah × V.
| Input | Result |
|---|---|
| 100 Ah at 12 V | 1,200 Wh |
| 100 Ah at 48 V | 4,800 Wh |
| 50 Ah at 24 V | 1,200 Wh |
Multiply by voltage: Wh = Ah × V. A 100 Ah 12 V battery stores 1,200 Wh — the same energy as a 25 Ah 48 V battery. Voltage is why two '100 Ah' batteries are not equal.
1,200 Wh ÷ 100 W = 12 h in theory; lead-acid should not be discharged past ~50%, so plan on 6 h. Lithium (LiFePO4) can use most of its rating.
System energy planning is done in Wh because loads are rated in watts. Converting each battery's Ah to Wh lets you compare 12 V, 24 V and 48 V banks fairly.