My S4 is shutting off completely randomly even when fully charged? And it can't be the battery...

[yosammyy]

Hey guys,
So I've been having this consistent issue with my phone now for about a month. My phone wasn't holding a charge, losing a charge quicker than it should and randomly turning off even when there is still battery left.
After looking online I saw that this issue meant a needed a new battery. Fine, no problem.
However, after buying one of the top rated batteries (anker brand), I still ran into the same problem.
I popped the new battery in and it was already slightly charge to a 40 something percent, assumed it was sent that way.
I turned it on and I was able to use it for a whole 3 minutes before it completely shut off without warning and now wont charge or turn on at all.
So my question is, what now?
What do you guys think?
Thanks.

 

[B. Diddy]

Welcome to Android Central! To be sure, charge that new battery up to 100% first, then try using the phone normally. If it still shuts down prematurely, then there might be a problem with the Power button (or worse yet, the motherboard). That would require a trip to a repair shop.