Im sorry if this been up before, but i just got my 5s and i noticed right now while its charging (now at 98%) that the phone is pretty warm. Much warmer than my old 4s. Is this normal? Its not burning hot, but surprisingly warm.
What are you using as the power source? The OEM block that came with the phone, or something else? If something else, it may be providing a higher amperage output than the OEM, giving you a bit more heat...
Also, are you using the phone while you charge? That can make it slightly warmer than if not using it. If it's just a bit warm, that's normal. If it feels hot, that's not normal.
I didnt use it, i left it charging when i was out and when i got home again it felt like a hand warmer.
When it reached 100% everything was fine again. This is only the 2nd time im charging it, maybe the battery gets better after a while. I have read that it needs 3-4 charging cycles for the battery to last longer. After the 1st charge i had 5 hours of usage then the battery was down to 4%. This time maybe i get 6 hours usage