Cell phone problem
 

Just recently my Motorola V400 phone felt warm. Then, about an hour later, it got a bit warmer. My battery meter was at 100% earlier and then after the warming was all the way down. Now, the phone was charged for about a day and still won't turn on.
Is the battery dead?
Is the phone dead?

I would say your battery just burnt itself out. I've heard of that happening and only a few instances in which the phone itself was affected. I would try a new battery or if it's too much, a new phone.

Does your phone work when the battery is out, yet still plugged in? I had the same problem with my T720 a couple years ago. All of a sudden I couldn't get it to turn on even when I knew it was charged. It ended up being the phone and luckily Verizon was nice enough to replace it free of charge.