Follow these steps to calibrate your phone’s battery:

1. Turn your phone off and remove the battery (if possible).
2. Leave the battery out for a few minutes.
3. Put the battery back in the phone.
4. Charge the phone up until it’s fully charged.
5. Turn on the phone and let it drain down to around 20%, then charge it back up to 100%.
6. Turn the phone off again and then remove the battery for a few seconds.
7. Put the battery back in the phone and turn it back on.
8. Your phone’s battery should now be calibrated!