I dropped a zippy once, and as far as I could tell it didn't hurt anything. It still works fine and I've never noticed any problems.

You should order some zippy flightmax batterys, and it could have only been a $20 mistake. Don't let the low price fool you, they have a great reputation in the RC community.

http://www.hobbycity.com/hobbycity/store/uh_index.asp