Sound like it went in to "Hibernation mode".....im sure its OK.......i think the book will tell you just how to wake It UP for a good charge OR some body here will soon........its a simple process you might see IF the below helps !
Geebax states this in a old thread :The batteries are completely discharged. When you put them on the charger, it applies a very slow trickle charge to them for a long period of time, eventually they have sufficient charge to wake up the internal processor and then they begin to fast charge as per normal. Just put them on the charger and leave them for a couple of hours.