QUOTE(Redundant @ Jun 8 2017, 09:28 AM)
Hi, is the GPS running constantly in the background when the phone is idle? If yes, try to go to settings> privacy > location services and see which app has a purple arrow icon beside it... means the app is using the GPS.
For my case waze was using the GPS eventhough I have put it to sleep, turns out to be there's this function called Location reporting that's causing the problem. The latest waze update should have this feature removed already.
Also, you can try checking the compass calibration and disable it if you dont use maps often.
Hope this helps

thanks a lot for your suggestion bro.
but yeah first thing i did was to disable everything because i know my mum dont need most of that feature. she just want to use the phone for her instagram. i used to own an iPhone and i prefer to disable everything because i want good battery life.
im at klcc machines service center now. they said that i cant update the software OTA. must use itunes. first time i heard that.

now he's trying to update using itunes and see what happens. he already diagnosed battery life still fine.
the thing is my mum use iPhone 6 Plus and my sis use iPhone 6 both on the latest 10.3.2 but no battery drain issue. this is the first time im having problem like battery drain. really macam air even when im not using it.
if he managed to solved it just by updating using itunes then really weird la.