What is Battery Power Capacity?

Power capacity:

It is the energy stored in a battery which is measured in Watt-hour

Watt-hour = V * I * hours {since voltage is kept constant, so it is measured in Ah/mAh}

 

We generally see the battery ratings as 2500 mAh or 4000 mAh while reading the specifications of a smart phone.

What does that mean?? Let’s see

 

Example: 2500 mAh it means that the battery has a capability to deliver 2.5A/2500mA of current to the load for 1 hour. The time that the battery works continuously depends upon the load current that it consumes. So if the load consumes only 25 mA of current then the battery can stay alive for 100 hours. How is it?

25 mA * 100 hours {so 25 mA of current for 100 hours}

Similarly 250 mA for 10 hours So on…

 

Though the theoretical calculations seem ideal but the battery’s duration changes based on the temperature and the current consumption etc.