Battery Runtime Calculator
Estimate how long a battery will run a load. Accounts for capacity, voltage, inverter losses and depth of discharge.
Frequently asked questions
- Why is runtime less than the nameplate rating?
- Three losses: you should not fully discharge most chemistries, inverters waste 5β15% converting DC to AC, and lead-acid capacity shrinks at high discharge rates.
- What depth of discharge should I use?
- 50% for regular lead-acid use, up to 80% occasionally. Lithium batteries tolerate 80β100% daily.
- What Peukert exponent do I enter?
- 1.0β1.1 for lithium, 1.1β1.3 for lead-acid. Higher values mean capacity drops faster under heavy loads.
This tool runs entirely in your browser. No data is uploaded anywhere.