I'll add my voice as well. I had a 5s that shutdown randomly at around 30-40%. On a hunch I replaced the battery and the problem was solved. I can't say if pe

I'll add my voice as well. I had a 5s that shutdown randomly at around 30-40%. On a hunch I replaced the battery and the problem was solved. I can't say if performance improved or not since I gifted it to someone.