Why is my s4 dying when switching to mobile data

[AC Question]

Hi! I have an s4 i9505 which keeps restarting in certain actions. I wake up, take it off the charger, 100% battery, do whatever for a couple of hours (not spending the couple of hours on my phone - moderate use), battery now at ~65%, I switch the wi-fi off and mobile data on (that seems to trigger it every time), the phone restarts a couple of seconds later and turns on with 0% battery, and then shuts off. If i try to turn it on, it does with ~45%, and shuts off. If i put in on the charger while off, it starts charging like it's completely empty and jumps to 45% a couple seconds later. Couple of minutes of charging is enough to make it last for another couple of hours then. Been to Samsung repair shop, they say it could be literally anything. 1 work hour over there is 20 euros just to find out what's the problem. New battery around 50 euros. Not trying either of those if it might not solve my problem. Hope somebody here had, and solved that problem. My ex had the same problem on s3 and she threw it away, bought a new phone... Thanks in advance. Alexander

 

[nahoku]

Is this the original battery that came with the phone? The phone was released in Mar 2013, so the battery is going on 4 years in just a few months. The symptoms where the battery percentage jumps erratically normally points to an aged/bad battery. Whether you want to replace it is up to you, but it's the first thing that comes to mind for people who have seen this many, many times. Batteries are lucky to last 2 years of extended use. Good luck!

 

[Alexander s4 gt-i9505]

Is this the original battery that came with the phone? The phone was released in Mar 2013, so the battery is going on 4 years in just a few months. The symptoms where the battery percentage jumps erratically normally points to an aged/bad battery. Whether you want to replace it is up to you, but it's the first thing that comes to mind for people who have seen this many, many times. Batteries are lucky to last 2 years of extended use. Good luck!

Yeah, the battery's original. I have it for 2 full years now, bought it second hand from a guy that had it for another year, maybe couple of months more. Was my first thought as well, but the guys at Samsung made me have second thoughts. Will try to borrow someone's battery or buy a cheaper replacement battery to figure if that's the problem. I mean I'll probably upgrade to s6 soon but would like to give this one to my mum lol. Honestly in these 2 years, this is the only problem I've had, a truly brilliant phone. Anyway thanks for the quick and nice answer! Cheers

 

[nahoku]

This is a good idea...

Will try to borrow someone's battery

This is a bad one...

or buy a cheaper replacement battery to figure if that's the problem.

I like the idea of borrowing a battery rather than investing in a cheap replacement. A cheap replacement, while it may work for a while, won't last that long and you'll find yourself (or your mum) replacing it again. After you troubleshoot with a borrowed battery and if it turns out that it is the battery, invest in a decent one as a replacement. If you can't get a Samsung OEM original, Anker has good reviews and support per this forum.