Method one: First download and install the app from Play Store: Battery Calibration 1. Launch the app and allow " Super User" . While the app is running, charge until the battery level is full (100%). As soon as the battery level is full (100%), click on the “ Calibrate / Battery Calibration” option. Now disconnect the device from the charger. When this is done, the device must be fully charged. Done! Method Two: If the above method does not work for you, then try this method. To use this method you need to have a functional recovery installed on the device. Boot into device recovery mode and manage Advanced> wipe battery stats . Now that the battery is fully discharged, the device must be fully charged while it is off (disconnection cannot be disconnected while it is charged , so make sure the power is connected). When the charge is 100% , turn on the device without disconnecting from the charger and launch the app above by clicking on the “ Battery Calibration” button. After some time, the message " battery calibration has been succeeded" will appear. Now click on the OK button, disconnect the charger from the device and close the app. Done! Method three: 1. Root Explorer ( or any other file manager that can use root directories ) Launch the file manager. Go to the “/ data / system” folder and find the “ batterystats.bin” file. Delete the file 4 days. Reboot the device and wait for the battery to run out. Device must be fully charged when off (disconnection cannot be disconnected while charging , so make sure power is connected). When the charge is 100%, turn on the device without disconnecting from the charger and launch the app above by clicking on the “ Battery Calibration” button. After some time, the message " battery calibration has been succeeded" will appear. Now click on the OK button, disconnect the charger from the device and close the app. Done!