Gator
This was 20+ years ago but I still remember one like it was yesterday

1978 Autocar 350 HP Cummins Diesel
4 12V batteries in one box
It was a thumb screw type switch which had failed ( Much more heavy duty than the ones I have seen posted for the Corvettes)
Due to the quality of the switch it kept making and breaking the ground contact while on the road.
Basically the sparks from the contact caused the batteries to explode and caused the fire.... New cab/hood/wiring all interior... and it was never the same after that

Second case was the same switch, same issue but this was a Ford Diesel, but this time the vehicle was not saved.
Twin batteries in one box....... burned to the ground on the side of the road......

No Fire extinguisher will save a car/truck from 4 or 2 or even one fully charged battery unless you have a good pair cable cutters and you can get access to the cables without getting burnt

We then switched to the larger more dependable ( more expensive ) switches which I have posted a few times.
1 2 or 4 batteries equals disaster in an enclosed area with a cheap switch......... just my opinion ... of course, I have seen it first hand

 

A buddy of mine lost a boat to a battery fire. He ended up using the marine 350 for a bouy anchor after that. Did I spell either of those last two words right?

 

I can't take this anymore, now i have to buy at least 1. Hobo Freight has them on sale for only $2.99! Just got thier flyer today - item #92688-2ASB, 100 amps continuous w/1000 amps surge.
BTW there's nothing to short to ground in a vettes fiberglass batt box.

cardo0

 

I like the battery disconnect switch and has worked well on the vette and the boat. It not only cuts all drain from the battery but is an additional security device because you can remove the ****. I know you can hot wire blah blah blah, but it's just one other measure.

 

Gotta love Harbor Freight. I bought a full tap and die set, high speed steel, for $20. I've used it several times now and how found no dulling or snapped taps.

 

Its not possible to over charge. They have a 13 volt regulating diode on them. Its apretty dumb system, but it works. The cells always put out 13 volts. As the battery approachs 13 volts current goes to 0. It is a painfully slow way to get a charge flow.

 

Hmm, well cool. One less thing to worry about and chalk up to myth.

 

Battery cut off switches are great as long as you don't mind re-programming your stereo everytime you go for a drive...

 

That's why they make them with a little thin wire and a little fuse. Enough power to keep your radio programs but not enough to start the car or quickly drain the battery or start a fire.... hopefully.

 

What is a stereo? I have 2 pipes that give me stereo!

 

 

Another option is wiring a small 9V battery to the stereos hot and ground wires. Add a diode so teh 9V can only go one way into the stereo and not backwards into the rest of the system. It'll be the only thing with a power source, and the rest of the car will remain 'dead.'