What is the meaning of mAh in battery specification ?

                     
                      If you observe the specification of rechargeable batteries, you can see something like this  3.7v 2100 mAh or  3.7 V 5000 mAh .... You can see this on your  mobile  phone's battery too.

Actually what is the meaning of these specifications.

The first one in the specification is the maximum voltage that can be provided by the battery. The second one represents the capacity of the battery.

You know that, as the mAh value increase, the battery capacity also increases.But what is the meaning of mAh.

mAh stands for milliampere hour

Suppose the specification of the battery is 3.7v 2100 mAh.

The battery provides a voltage of 3.7 v

If we are taking a current of 1mA form the battery ,The battery can provide 3.7 v supply for 2100 hours.

If we are taking a current of 2100mA form the battery ,The battery can provide current for 1 hour.

So as the current taken from the battery increases ,the time for which the battery gives the rated voltage decreases.

Time (h)= mAh rating of the battery / current drawn from the battrey (mA)

In the case of charging the batteries, it also follows the same equation.

If we are using a supply that can provide a  current of  100mA. To charge the battery to full , it will take almost 21 hours.