I have a similar problem with my p600. the tablet is new, got it since a month or less.
at first i was amazed of the battery life i use it a lot for work writing documents and sheets on excel, battery used to perfom quite well giving me more than 5 hours of screen on, but recently the battery starts to drop very fast, now i can barely get around 2 hours of screen on.
i've already done 2 cycles of full discharge and then charge it completely with the tablet turned off. but the problem stills.
also sometimes when i reboot the tablet the battery goes from i.e 20% to 40% after the reboot.
im still looking for a fix or solution, today i found a new official firmware for my model (4.4 firmware for telcel mexico). going to wait until the tablet is fully charged and then flash the new firmware. I dont know if its going to help but i got nothing to lose.
by the way, sending it to semsung is not an option because of knox 0x1
Phone: Samsung galaxy S4 (i337M)
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