Calculator
Battery energy and charge cost
Enter the voltage and capacity from the battery label or listing, how often you charge it and the unit rate in p/kWh from your bill.
In short
Wh = V x Ah (mAh / 1,000 = Ah). kWh from the wall = Wh / 1,000 / charger efficiency (0.85 by default). Pence per charge = kWh x p/kWh, and per year = per charge x charges per week x 52. Example: 25.2 V x 2.8 Ah = 70.6 Wh, about 0.083 kWh per charge.
Work out energy and cost
- Battery
- 70.6 Wh
- From the wall
- 0.083 kWh
- per charge
- Per charge
- n/a
- Enter your unit rate
- Per year
- n/a
Common battery packs
| Pack | Energy | From the wall per charge |
|---|---|---|
| 18 V, 2.0 Ah | 36.0 Wh | 0.042 kWh |
| 21.6 V, 2.5 Ah | 54.0 Wh | 0.064 kWh |
| 25.2 V, 2.8 Ah | 70.6 Wh | 0.083 kWh |
| 25.2 V, 4.0 Ah | 100.8 Wh | 0.119 kWh |