So I’ve flashed a couple different ROM’s on my Galaxy S2 and figured I should re-calibrate the battery. I found this thread over on XDA about calibrating the battery, and thought I would post it here (for personal reference) and also for anyone else interested. All props go to ram3n at XDA.
Unlike HTC devices, battery calibration doesn’t apply to our devices. Google MAX17040 for more info – while our fuel gauge chip (MAX17042) does have advanced features that would require calibration if used, those features are not yet enabled and it basically behaves identically to a 17040. Maxim specifically designs their fuel gauge chips to not require special calibration procedures.
So, here are the steps to calibrating the battery for the Galaxy S2.
1. Turn off your phone.
2. Fully Charge.
3. When getting 100% signal, unplug.
4. Pull out the battery.
5. Wait for 3 – 5 minutes (take this opportunity to clean internals).
6. Put the battery back in.
7. Turn on the phone.
Once you have completed this, do a full cycle (let battery run down to roughly 5% then fully charge).