Connect the Phone to USB on PC and Format the DATA clean all folders, then go Recovery and do factory reset and wipe cache 3 times, then go download mode and flash the firmware 4.4.2 with odin 3.09.. and see if you got battery drains again.
Dunno if its the correct way but thats what i will do it to test :X
Dunno if its the correct way but thats what i will do it to test :X