* Pavel Machek <pavel@xxxxxx> [190818 18:35]: > Hi! > > > Recently my Droid4 battery seems to be swelling up quite a bit. It could > > be of old age, but bencoh (CC) suggested that he changed the driver code > > in his kernel to charge until 4.2v, instead of the 4.35v that mainline > > currently seems to use. (After one of his batteries started to swell up too) > > > > I assume the 4.35v value was taken from Android? Yes the values we have been using are the values dumped from Android. So far I have not seen anything changing the values when left connected to a charger, so I was assuming/hoping that the charger hardware might drop the voltage automatically.. But it seems that's not the case. I too have seen at least two swollen batteries and at least one that seemed to happen with Cyanogenmod or LineageOS few years ago. I suspect it happens if left connected to a charger for a longer period of time like several weeks at a time. > You can let stock android charge the battery, then read voltage from > mainline kernel. It seems stock uses 4.35V: > > https://forums.lenovo.com/t5/Moto-Z/MOTO-Z-EXTREME-BATTERY-DRAIN/m-p/4435636 > > ...but maybe we should not. OK so sounds like Motorola always keeps the voltage at 4.35V and there's no need to try to dump out any more charger related values from Android. > https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries Pavel, care to send out a minimal fix to lower the charge voltage to 4.2V since you have the related changes already? Then later on we may want to optionally consider implementing support for 4.35V charge voltages assuming we scale down the charge voltage to 4.2V after reaching full charge. Regards, Tony
