Help Flashing led

[BigDaddy2k9]

My Evo battery was low, plugged in my charger and the notification led was flashing amber and red. powered off, still flashing,popped battery, and noticed to bottom half of the phone was really warm, put the battery back in, turned on the phone and plugged the charger back in and now its fine. checked my manual and didnt see anyhing like this.
Any ideas?

 

[exBBuser]

How low was it. I've seen mines doing the same thing when the battery is really really low and is begging for a refill.

 

[BigDaddy2k9]

It was pretty low,like below 10%, it charged really fast,like in less then an hour. wondering if I have a battery issue.