Battery percentage shown in lockscreen while charging is incorrect

I have a Samsung Galaxy S-III (rooted & running 4.4.4) with a peculiar problem.

According to the Notification Bar toggles, the battery percentage is 82%. The same is shown in Settings > Battery.

However, when I plug it in for charging, it shows "Charging, 49%". After some time on the power, when the actual percentage was 99%, the lockscreen showed 69%. According to the custom Kernel, the battery percentage in the notification bar and settings is correct. Therefore, it must be something to do with the lockscreen widget.

Does anyone know how to fix this? Any help is appreciated.

Things I have tried:

• Reboot


• Factory Reset and Wipe Caches