Chosen Solution
So i just got a battery replacement, and i was wondering why i got no low battery notifications. So i charged it to 22 and used until it hit 20, once it did it immediately shut off, tried to reboot, then showed as dead.
Let the battery die and then charge it for a few hours, do this a couple times, this is what my friend did to stop his 5S from doing this, it may work for you as well.
