Instant calculator
Battery Life Calculator
Use the battery life calculator to estimate how long a battery may support a constant electrical load.
How to use
Quick steps
- Enter battery capacity, usable capacity, load current.
- Review the instant answer block and supporting calculations.
- Compare the result with related tools in the same category before making a decision.
Formula
How this calculator works
Runtime = battery amp-hours x usable capacity / load current
Real runtime varies with discharge rate, temperature, battery age, and inverter losses.
FAQ
Common questions
How does the battery life calculator work?
It uses Runtime = battery amp-hours x usable capacity / load current. Enter battery capacity, usable capacity, and load current to generate an instant estimate.
When should I use this battery life calculator?
Estimate runtime from battery capacity, load current, and usable capacity.
What should I keep in mind?
Real runtime varies with discharge rate, temperature, battery age, and inverter losses.