Quit playing with the cache partition for everything loll just kidding , do you use a car charger sometimes? some of these chargers are not smart to disconnect when the battery is full and can overheat and damage it !!!!
If you only use the original charger which is not great to start with needless to mention the original USB cable that is giving lots of a people a hard time, may be you have a problem with that but honestly between the Kitkat tons of bugs and the cheapo Samsung charger there's no telling which is which, me personally I am using an old nokia usb charger that came with my Nokia N8 for 2 years then used it with my Samsung S3 for 2 years and now I am using it with my note 3 it's fast and reliable and never failed me, my Samasung S3 and note 3 chargers are still sitting in the boxes, I don't use them.