Chosen Solution
I replaced the battery and it worked fine, then started dying at 10% charge, then 20%, now it dies at 63% of charge, reboots and shows 3%. It has been about 3 months since I did the battery change, and it keeps failing sooner every day.
This seems to be a gas gauge problem. There is a battery gas gauge component (SWI) near the battery, if it has been knocked off or nudged it will cause the problems you are facing. It used to be a common problem after a battery replacement on these phones. Usually we would rule out a faulty battery first but this component is easy to examine so we would check it and move on to replacing the battery with a known good one.
Get the battery replaced. Loads of faulty ’new’ batteries kicking about.
Hi! Is your battery calibrated properly? If not, follow this guide. Also, Mind showing us information about your battery by using coconutBattery 3 so we can understand and investigate the problem? Cheers, Artem.
Artem, are you iFixit staff? I don’t download apps from random folks in forums.
