Electrical Calculators
Battery & Energy

Battery Runtime Calculator

Battery Runtime Calculator. Battery energy, capacity and simple runtime estimates with explicit usable-capacity assumptions. Calculations run in your browser. Entered electrical values are not uploaded to our server.

Inputs
{{/each}}
Calculations run in your browser. Entered electrical values are not uploaded to our server.
ⓘMathematical estimate only. Verify equipment datasheets, manufacturer instructions, electrical codes and qualified design before real-world use.

Formula & method

Nominal Wh = V × Ah; usable Wh = nominal Wh × usable factor; runtime = usable Wh / load W

Worked example

12 V × 100 Ah = 1200 Wh nominal; at 90% usable and 120 W → 9 h

Assumptions & safety boundary

Mathematical estimate only. Verify equipment datasheets, manufacturer instructions, electrical codes and qualified design before real-world use.