I went to get my car out of storage only to find at some point the battery exploded. It was on a tender as per every year for the last 6 mos.

Battery compartment without spare tire

what's left of battery
I don't know where to start after I clean it up out of the trunk well with baking soda and rags. Is it safe to attach a new battery? The fuse box is right next to battery. Should I have it towed to a garage before I try to start it? What kind of body damage done on an aluminum body? Is this a possible insurance claim?

 

try to identify any electrical connections that got any acid on them. They will need to be replaced as they are probably etched and wont conduct well. If none clean up the trunk and battery terminals and baking soda the bejesus out of it and try another battery


what battery tender did u have? How old?

 

Indeed! What would have caused this? I keep mine on various battery tenders and try to start them occasionally too.

 

I think it has to be a faulty maintainer or it's not actually a maintainer.

 

I've already posted numerous times about my experience with "low budget" battery maintainers. Some of the cheaper ones can fail in the "full on" position so you want a "smart" charger that will shut off if it detects a problem. I always have several cars plugged in, but luckily I visited them in storage in time to hear the sound of a battery boiling while attached to a Sears Diehard brand unit. After that I switched all my cars to the slightly more expensive Battery Tender brand units. Few years later I had a couple of those fail "off" and thought that was OK, just disappointing and replaced them. Later I had an issue with a 69 Corvette that if I didn't get the worn out ignition switch in just the right spot before removing the key, the accessories would remain energized. The BT brand couldn't recognize the problem and shut itself off, but rather kept charging despite that it didn't put out enough amps to keep up and blew the caps off the battery when I tried to start the car because it had boiled the battery producing hydrogen gas. After that, I switched everything to about twice as expensive CTEK brand units which are supposed to detect charging problems and shut themselves down. Please just don't tell me this happened with a CTEK brand unit.