Watt Hours to Amp Hours Converter (Wh to Ah)
Convert energy in watt-hours back to battery capacity in amp-hours for a 12V, 24V or 48V bank. Essential when a load is rated in Wh or kWh.
Convert Watt-Hours to Amp-Hours
Conversion Result
At 12 V nominal battery voltage
Lead-acid banks are sized at twice the usable capacity needed
LiFePO4 banks can use 80% of their rated capacity
Step-by-Step Engineering Calculation
- 1Charge capacity:
- 2Use the battery's nominal voltage (12 V, 24 V, 48 V), not its fully charged voltage, so the rating matches how manufacturers label capacity.
Conversion Formula & Relationship
Dividing stored or consumed energy by the battery's nominal voltage gives the charge capacity in amp-hours, the unit batteries are sold and labeled in.
Standard Conversion Example
A 2,560 Wh power station rating equals 2,560 / 12 = 213.3 Ah at 12 V nominal. The same energy at 48 V would need only 53.3 Ah.
Quick Reference Conversion Table
| Watt-Hours (Wh) | Amp-Hours (Ah) | Common Application / Context |
|---|---|---|
| 600 Wh @ 12V | 50 Ah | Small power station |
| 1,200 Wh @ 12V | 100 Ah | One deep-cycle battery |
| 2,400 Wh @ 24V | 100 Ah | Off-grid cabin bank |
| 5,120 Wh @ 48V | 106.7 Ah | Standard 5.12 kWh wall battery |
| 10,240 Wh @ 48V | 213.3 Ah | Whole-home backup |
Frequently Asked Questions
A power station says 768 Wh. How many Ah is that?
Divide by the voltage you are comparing at. At 12 V it is 64 Ah. Note the power station's internal battery may run at a different voltage, so Wh is the honest figure for comparing energy across products.
Should I size my battery bank from Wh or Ah?
Start from energy: add up the watt-hours your loads consume per day, then convert to Ah at your system voltage and add margin for depth of discharge and inverter losses.