How it works
Estimate runtime from nominal energy and a usable-capacity allowance. Battery chemistry, temperature and current-dependent losses are not modelled.
Inputs and units
| Input | Example value | What to enter |
|---|---|---|
| Battery voltage | 12 V | Required unit: V. Must be greater than zero. |
| Capacity | 100 Ah | Required unit: Ah. Must be greater than zero. |
| Load power | 100 W | Required unit: W. Must be greater than zero. |
| Usable capacity | 80 % | Enter the percentage as a number: for 15%, enter 15. Must be greater than zero. Allowed range: 1–100. |
Worked example
Show example inputs and results
This example is generated by the same calculation engine using the starting values in the form. Your own inputs produce your own result.
- Battery voltage
- 12 V
- Capacity
- 100 Ah
- Load power
- 100 W
- Usable capacity
- 80 %
Complete example results
- Runtime
- 9.6 h
Reading the result
Convert measurements to the same unit and use the net area to cover. Replace any package, waste or efficiency input with your product information. A quantity estimate alone does not determine installation conditions.
Questions and answers
Can I use the example values for my own calculation?
The example values illustrate the calculation. Replace every input with your own information, especially dates, rates and the selected operation.
Why are some results rounded?
Results display up to 8 decimal places. Calculations use the unrounded values; very small values use scientific notation. JavaScript floating-point arithmetic can introduce tiny rounding differences.
Are my inputs sent to a server?
The calculator processes inputs in your browser. Its code does not send your values to a server.