Battery Life Calculator
Generally, battery life is calculated based on the current rating in Milliampere (mA) and the capacity of the battery in Milliampere Hours (mAh). Ampere is an electrical unit used to measure the current flow towards the load. The battery life or capacity can be calculated from the input current rating of the battery and the load current of the circuit. Battery life will be high when the load current is low and vice versa. The capacity of the battery can be mathematically derived from the following formula:
Battery Life = Battery Capacity in mAh / Load Current in mA * 0.70
*The factor of 0.7 makes allowances for external factors which can affect battery life.
Runtime = (10 * Ampere Hours) / Load in Watts