I always find it amusing when somebody crashes and the post inspection identifies battery failure. They always seem to come out with the best one liners such as "well it's never done that before" or "I've had this battery for 20 years and it's always been reliable - until now" or "I don't know why it failed now - it's only had 1000 flights on it" ...........etc.
Do yourself a favour and just invest in a new one. Go Sanyo eneloops if you budget allows - they are cheap insurance.