Basic Battery Life Calculator is an online calculation tool to calculate battery life in hours from the known battery capacity in mAh or Ah and load device current in mA.
Battery Life Calculation Formula
B(l) = B(cap)/L(c)
- B(l) = Battery lifetime in hours
- B(cap) = Battery capacity in Ah or mAh
- L(c) = Load device current draw in µA, mA, A, or kA
Previous formula can also be expressed as
Battery Lifetime = Battery capacity in mAh/Load device current draw in mA
Examples
A 2500 mAh battery can supply power to 200 mA load for 12.5 hours.
Calculation
Battery lifetime in hours = Capacity/Load device current = 2500 mAh/200 mA = 12.5 h