For those who think "this will never happen to me", think again. On July 20th, the AARC Generator failed ot start. This exploded battery was the culprit. The explosion was most likely caused by rapid overcharging. We teach how to avoid this in our Technician Classes. This morning I added this picture to this Fall's lesson plan.
So if you have any equipment that automatically recharges a lead acit battery, please consider checking the charging current, and making sure that your charger cuts back to trickle charging after the battery has reached full voltage.
Meanwhile we are considering changing the charging system used by the AARC Generator, so this won't happen to us ever again.