Unfortunately, I have been the cause of one of those in pit battery blow ups....
Got some cells from a fellow racer and proceeded to charge them. Well, my mistake was to not discharge before charging. Ironically, I was in the middle of a race on the stand when it all went down. About half way through the race....KABOOM!!!!!! I couldn't believe it was my pit!!!
Two lessons learned...
1. ALWAYS DISCHARGE BEFORE CHARGING.
2. Don't run too many classes on a weekday club race. Concentrate on one class to not rush myself....
Thankfully, only damage was a little pride hurt and a heck of a mess to clean up...