Why wont my S4 turn on?

[AC Question]

So I have had my Galaxy S4 for about 2 months now and since I got it, it has had a problem of randomly turning off. For a temporary fix I would plug it into my power bank or take out the battery and put it back in and it would usually turn on without problem. It would turn off at random battery percentages so I don't think it was the battery (and the battery has always been a pretty good one). It just so happens that today I was texting and streaming music, and it randomly turned off again. This time when I tried the things I had been doing earlier it would show the Galaxy S4 logo just like it always did and turn off again. Sometimes when i tried to turn it back on it would make it all the way, but as soon as I unlocked it, it would immediately turn back off. I have tried 5 different chargers (including the original), trickle charging, hard and soft resets, everything I could think of. Still nothing has worked. I do not have a warranty on it either. Thanks for helping me in advance.

 

[Rukbat]

Sounds like the battery is growing dendrites. That happens randomly, so it could cause the phone to die at 90% charge, 40% charge, anywhere. Once the dendrite grows, shorting the battery, the current flowing through the dendrite (which is what causes the phone to shut off, because the battery is shorted) blows the dendrite away, and the phone works when you turn it on. (Go to the battery page in Settings, click on the graph on top to get to the second page and look for the "cliff" - the voltage will drop to zero in no time - just a vertical drop. then when the phone is back on, it'll be at the same charge level or a slightly lower one.)

The only remedy for that at this time is a new battery. If you search lithium battery dendrite, you'll see that the battery industry is still trying to figure out how to attack the problem. (Replacing a $15 phone battery isn't that bad. Replacing a $2,000 hybrid or electric car battery - under warranty - is a serious problem for the automotive industry.)