Help weird battery issue

[2k1dakotaman]

Somedays i have worst days then other....in one hour the battery will drop 10 to 15% and sometimes its good....whats weird say my phone is at 54% and i take the battery out and start the phone back up.....and when the phone starts it has 80% or something...anyone else have this issue or had this happen before

 

[Rukbat]

I've seen posts of this kind of behavior, but there's no single definitive cause. Without having the phone in hand the best anyone can do is make wild guesses - like a bad battery, a miscalibrated phone, a rogue app, etc.