So after doing a couple of flashes for new roms with your phone you may experience some of these problems
1. . Using more then 10% battery in an hour or less
2. . While plugged into the charger you lock screen shows a different percentage charge then the battery icon
3. . After a full charge your battery icon only shows 99% and quickly drains.
4. . Any general weird battery activity
Well there is a way to fix that
1. . Flash the Rom on a full battery. (skip to step 6)
2. . If you flashed on less then full plug into AC charger asap and charge to full while the phone is powered on
3. . Once the phone blinks full 2.1-battfull popup shows 2.2-battery sign shows on left of notification bar power off
4. . Charge till full while powered off. the phone will vibrate and the green battery will show 100% in white text
5. . Unplug phone and power on.
6. . Using Root Explorer or a comparable program navigate to (Mount R/W first): data>system> and delete file batterystats.bin
7. . Reboot
8. . While the phone reboots it will rebuild that file and the software and phone should now match.
9. . If any of the symptoms persist start at step 2 and repeat.
10. . As with any rechargeable battery fully discharging the battery once in a while isn't a bad idea
if that doesnt work then try this method which has worked for me in the past
1. Connect the phone to the charger with the phone powered on, and allow the phone to charge until it shows 100%
2. Disconnect the phone from the charger, and power it off.
3. Reconnect the phone to the charger with the phone powered off, and allow the phone to charge until the battery indicator shows 100% (you can use vol-up/vol-down to make the indicator come back up when the screen goes to sleep).
3a. Repeat step 1, 2, 3
4. Disconnect the phone from the charger and power it on.
5. Once the phone is powered completely on, power it off again and reconnect it to the charger until the battery indicator shows 100%.
6. Disconnect the phone, power it on, and use it.
7. Use ADB or a Terminal Emulator to run the following command:
7a. Reboot into clock work Recovery, and choose advanced CWM features and select wipe battery stats
Make sure if this is your first time using adb on your phone that you allow Super User permission to access the phone or else you wont be able to do the coding for the phone battery reset