Enter the battery capacity and power consumption into the calculator to determine the battery drain time. This calculator can also evaluate any of the variables given the others are known.

Battery Drain Time Formula

The following formula is used to calculate the battery drain time.

T = C / P

Variables:

  • T is the battery drain time (hours)
  • C is the battery capacity (mAh)
  • P is the power consumption of the device (mA)

To calculate the battery drain time, divide the battery capacity by the power consumption of the device. The result will be the time in hours that the battery will last before it is completely drained.

What is a Battery Drain Time?

Battery Drain Time refers to the duration a battery can last before it is completely discharged or drained. It is determined by the battery’s capacity and the power consumption of the device it is powering. The higher the device’s power consumption, the shorter the battery drain time. This concept is crucial in devices like smartphones, laptops, electric vehicles, etc., where battery life significantly impacts the user experience.

How to Calculate Battery Drain Time?

The following steps outline how to calculate the Battery Drain Time.


  1. First, determine the battery capacity (C) in milliampere-hours (mAh).
  2. Next, determine the power consumption of the device (P) in milliamperes (mA).
  3. Next, gather the formula from above: T = C / P.
  4. Finally, calculate the Battery Drain Time (T) in hours.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

battery capacity (C) = 3000 mAh

power consumption of the device (P) = 500 mA