Battery Capacity Calculator
Quickly calculate battery capacity (Ah or Wh) and runtime for DC loads; includes conversions, depth-of-discharge, efficiency, series/parallel sizing, and worked examples.
battery capacity for inverter
To estimate battery capacity, load power (W 0) multiplied by runtime (h) equals energy in watt-hours. Divide the number of units of Wh by the system voltage to change units into ampere-hours. Efficiency and depth of discharge adjustment to size in the world.
Formula & Table Summary:
Energy (Wh): Wh = P_load × t
Ah from Wh: Ah = Wh ÷ V
Required Ah: Ah_req = (P_load × t) ÷ (V × DoD × η)
Runtime: t = (Ah_bat × V × DoD × η) ÷ P_load
battery storage kWh calculator
A battery capacity calculator is useful to calculate the size of a battery (in ampere-hours, Ah, or watt-hours, WH) required to provide power to an object over a specific time. Entering load power, runtime, voltage, depth of discharge (DoD), and efficiency will compute the size of the required battery. The equations give a relationship between Wh and Ah of battery storage. The tool can be effective in sizing batteries used in solar, backup, UPS, EV, or off-grid applications.
battery capacity calculator
| Scenario | Inputs | Result |
|---|---|---|
| Lamp 60W, 10h | 12V, DoD 50%, η 95% | Ah_req ≈ 105 → 120 Ah |
| Backup 300W, 4h | 24V, DoD 80%, η 90% | Ah_req ≈ 69 → 75 Ah |
| Solar 1kW, 2h | 48V, DoD 60%, η 88% | Ah_req ≈ 79 → 80–100 Ah |
| EV 20 kWh | 400V, DoD 90%, η 90% | Ah_req ≈ 62 Ah pack |
