Battery Runtime Estimator
Estimate ideal runtime from capacity, voltage, load and supplied usable fraction.
Your inputs
Calculation results
Formula & assumptions
Runtime = capacity in Ah × voltage × usable fraction/load watts; actual discharge behavior varies.
Values use the specified units. Calculations use floating-point arithmetic. Check input measurements and formula assumptions before applying the result.
Compare your scenarios
Save up to five results to compare changes side by side. Scenarios stay in this tab until you clear or reload it.
Using Battery Runtime Estimator
Estimate ideal runtime from capacity, voltage, load and supplied usable fraction.
- Enter battery capacity, nominal voltage, load power, usable fraction using the units printed under each field.
- Choose Calculate, or enable live updates. Review the result labels and formula assumptions.
- Save scenarios to compare up to five variations, then copy the report or download JSON or CSV.
Example
Battery capacity: 10000 milliamp hours Nominal voltage: 3.7 volts Load power: 10 watts Usable fraction: 80 percent Nominal energy · watt hours: 37 Usable energy · watt hours: 29.6 Estimated runtime · hours: 2.96
Questions & answers
What does Battery Runtime Estimator calculate?
Estimate ideal runtime from capacity, voltage, load and supplied usable fraction.
Which units should I enter?
Battery capacity uses milliamp hours. Nominal voltage uses volts. Load power uses watts. Usable fraction uses percent. Convert values to these units before calculating.
Which formula does it use?
Runtime = capacity in Ah × voltage × usable fraction/load watts; actual discharge behavior varies.
What does the included example show?
Battery capacity: 10000 milliamp hours; Nominal voltage: 3.7 volts; Load power: 10 watts; Usable fraction: 80 percent. Result: Nominal energy · watt hours = 37; Usable energy · watt hours = 29.6; Estimated runtime · hours = 2.96.
Can I compare different settings?
Yes. Save a scenario, change the inputs and save another result. Up to five scenarios are compared in this tab; they disappear when you reload or leave.
Can I export the calculation?
Copy the JSON report or download JSON and CSV with inputs, result labels and numeric values. Processing uses local JavaScript; no calculation request is sent to our server. Displayed values use up to 10 significant digits; exports retain JavaScript numeric precision.
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