I mentioned a few days ago I had a G1 phone in there I mentioned the battery life was shocking . nabil2199 mentioned a battery calibration link it really does work.
That article wasn’t the most clear in the world of what you need to do to calibrate your battery.
1) Let it discharge completely(Even when it says it is dead carry on discharging, mine ran on 0% power for a good few hours)
2) Charge it fully while it is off.
3) Let it discharge completely again.
4) Charge it fully.
It seems silly but it does work, My battery life has improved so much since doing this silly thing.
