Battery Runtime Estimate
Estimate usable energy and constant-load runtime.
Your numbers
Estimated runtime
Ignores rate-dependent capacity, ageing, temperature, voltage sag, standby losses and battery management limits.
Scenario comparison
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Formula
Use t = VCfη/P. V is nominal voltage in V, C is capacity in Ah, f is usable discharge fraction, η is conversion efficiency as a fraction, and P is constant load in W. Runtime t is in hours.
Estimate usable energy and constant-load runtime.
Worked example
- Nominal battery voltage (V)
- 12
- Capacity (Ah)
- 100
- Usable depth of discharge (%)
- 80
- Conversion efficiency (%)
- 90
- Constant load power (W)
- 100
- Estimated runtime
- 8.64 hours
- Delivered usable energy
- 864 Wh
Scope and limitations
Ignores rate-dependent capacity, ageing, temperature, voltage sag, standby losses and battery management limits.
Inputs are checked for missing values and allowed ranges. A result outside the finite numeric range is not displayed. Rounding affects display, while the calculation uses the model’s numeric precision.
Check your units and assumptions before relying on a result. Changing a label does not convert a currency or physical unit.
Formula version: bb29e50ebc8c · Example checked: