As a mechanic I deal with cars and batteries (mostly lead acid type, non leisure) on a daily basis, I can honestly say I have only ever witnessed 1 battery disaster in all my 40 years on the job, (thankfully) however this actually happened.
A car battery was disconnected from its wiring terminals and one of the apprentices left it on charge overnight, he didn't notice the strong fumes coming from it the following morning, and he must have left the ignition switched on because when he removed the charger and reconnected the cars battery cables the small spark ignited the whole thing and the battery literally exploded.
luckily he wasn't hurt but it made a huge mess all over the engine bay.
batteries seem such harmless things until it goes wrong, 700 amps is an awful lot of current if things go wrong.
A car battery was disconnected from its wiring terminals and one of the apprentices left it on charge overnight, he didn't notice the strong fumes coming from it the following morning, and he must have left the ignition switched on because when he removed the charger and reconnected the cars battery cables the small spark ignited the whole thing and the battery literally exploded.
luckily he wasn't hurt but it made a huge mess all over the engine bay.
batteries seem such harmless things until it goes wrong, 700 amps is an awful lot of current if things go wrong.