Android Calibration

[VeraP]

My Android smartphone turns off when reaching to 13% and battery power does not remain until it completely finishes..So, I tried to calibrate the Android battery and It seems to be okay..But, the calibration process needs to be done regularly. It's bothersome and checkout some calibration apps..But most of them require root access. I need to know a calibration app that can work without root access? Any suggestion

 

[HomerJay]

Which phone and how old is it? Is the run time / screen on time decreasing? Maybe the battery IS broke and needs to be replaced?