Originally Posted by
Duster_360
It could be old and used up or could be badly damaged, hard to tell. Could have been left in his RC with the esc still connected and drained that way.
Regardless, its done, even with you jump starting it, it prob doesn't have the punch it should.
+1 It definitely sounds like it is just an old battery to me. Maybe it was run past cut-off a couple times maybe not, but it definitely sounds that the poor battery has seen its time..