Maybe I just have a penchant for outing myself as a putz
In case it benefits someone else... I was headed north on a camping trip with my kayak, and had my SLA 12v batteries (main plus spare) in a milk crate with all of my kayak repair stuff and other odds and ends.
As we got to the camp site, I was sorting stuff in back of my truck, and pushed a mesh bag with a chain stringer in it down into the crate... Almost immediately smelled smoke, and had a flame flare up in front of me. In a matter of seconds, the chain had shorted out the battery terminals, and turned itself into a soldering iron, setting my mesh bag on fire. I'm just lucky it hadn't happened while I was driving and not right in front of me.
Was a nice harmless lesson in keeping my terminals covered.