Android 'remembers' the state of the battery internally the disadvantage of this is that when the state of the battery changes as a result of charge cycles and age the Android system will not adjust itself accordingly.

For rooted users the procedure is a lot easier the app will ask for root permission. When root permission is granted the app will apply a fix that forces Android to recheck the state of the battery.
This will rebuild the battery state and repair any battery measuring issues.

For non-rooted users there is an detailed description of the procedure as it will be different than it is for the rooted users.

If you do not notice any difference then your battery might not have changed. Keep this app installed to be prepared for any future battery changes.

In advantage to the calibration of your battery this app will also diplay some useful statistics. Such as:
- The remaining battery percentage (and the mAh remaining to charge)
- The battery voltage
- The battery capacity
- The battery technology
- The battery condition
- The battery charging state (with the type of charger)
- The battery temperature