Lockscreen Charge Monitor is a feature in dfndr battery that monitors the status of your battery while your phone is charging and indicates steps to prevent overcharging.

To use it, you first have to grant dfndr battery Accessibility permissions. After that, open the app and touch the Menu in the top left corner  > Select “Settings” > and then find “Lockscreen Charge Monitor”.

Slide the button to the right to enable it, or to the left to disable it.