Why include depth of discharge?
It lets you model only the fraction of nominal energy you intend to use.
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Battery Runtime Calculator — Ah, Wh, DoD & Efficiency
Estimate battery runtime from amp-hours, voltage, load power, usable depth of discharge and system efficiency with all assumptions visible.
Result
8.64 h
Nameplate energy: 1,200 Wh
Ideal runtime: 12 h
Usable energy after DoD and efficiency: 864 Wh
Adjusted runtime: 518.4 min
Formula and worked example
runtime h=(Ah×V×DoD×efficiency)/load watts.
A 100 Ah, 12 V battery at 80% usable DoD and 90% efficiency feeding 100 W gives about 8.64 h in the simple energy model.
Assumptions
- Battery voltage is treated as constant for the energy estimate.
- Real runtime varies with chemistry, discharge rate, temperature, aging and inverter behavior.
Last updated: 2026-09-16
Frequently asked questions
Will real runtime exactly match?
No. This is an energy-balance estimate; real batteries are not ideal constant-voltage sources.