I have been recently experiencing battery level drops, and to my understanding my observations may have not been documented in the same way earlier by other users. The phenomenon is similar to what was reported by another usere here, or here although with some differences.
- There is apparently no single app that drains more energy and that is causing the battery drop.
- The battery level tends to fall rapidly only when it's down to about 40% or below, but not any 'earlier'.
- When the phone shuts down, it sort of carries the information that the battery level is null, and for this reason one cannot turn on the phone again. When re-charging, the battery level reportedly rises to about 2-3% and only at this point the phone can be turned on again. When the OS is fully loaded, the battery indication gets back to a good 50-70%. This seems to be a genuine reading since the phone can stay on for quite some time even after 'immediate' unplugging.
I wonder whether an option is a factory reset, though one does wonder whether there is a cause to this and if it can be addressed.
Android version is is 6.0, security patch level 2016-07-01, kernel 3.10.84. The Phone is an LG G4. Not rooted, untouched.