Battery experience after one week with Android 9:
Until last week (running Android 7) my battery (FP2-BAT02, 2440 mAh) drained fast to zero when reaching about 30% capacity. I assumed that it was weak due to its age of ~3 years and my bad habit of letting the phone plugged into USB of my notebook at work the day over. I know that’s a bad idea and I promise improvement.
After installing Android 9 the drainage was even worse and the percentage varied between restarts, so I feared I had to buy a new battery. But before disposing it I tried the following, with success until now:
- charge until 100%
- use until 0% and auto switchoff
- restart without charging until phone doesn’t start any more
- remove and insert battery after some minutes
- repeat step 1) to 4) several times (I did it three times)
As a result, the third charging went smothly from 0% to 100% and lasted significantly longer than before. The battery seems to be recalibrated and drainage is nearly like at the beginning. With all services switched on all the time and moderate usage including Spotify, some surfing, WhatsApp, E-mail, public transport app, tracking of hikes the battery lasts a hole day!
I hope this remains stable, fingers crossed.