I once saw two marine lead-acid batteries explode and catch fire in the boat next to mine when the owner had dropped something big enough to short circuit and not disintegrate itself. Instead a fat copper cable exploded and then probably both batteries boiled, exploded and then everything caught fire. It took about 3 seconds.
Luckily he avoided the acid spray, but he had to empty 4 large fire extinguishers from the nearby boats to put out the fire and cool down the remains of the batteries enough so they did not immediately catch fire again.
I have a huge respect for what a huge solar array and a big bank of batteries can do after seeing what a relatively puny battery could actually do.
A standard AC system can't deliver even a percentage of that current.
I had something similar happen to me in a Datsun 180B once.
Driving home in the rain, and the tail light wires were submerged in water that was pooling in the trunk and shorting out. As I put my foot on the brakes - on the freeway in the pouring rain - the fusible link in the engine bay decided to just catch on fire instead of being a fusible link. The battery quickly boiled and I had a sudden and catastrophic engine bay fire on a crowded road.
A car battery has enough amps to literally use as a welder (two jumper leads, an arc welding rod and a 550CCA car battery is enough to stick most things together in an emergency :P ), and is more than enough to create a massive fire.
Luckily he avoided the acid spray, but he had to empty 4 large fire extinguishers from the nearby boats to put out the fire and cool down the remains of the batteries enough so they did not immediately catch fire again.
I have a huge respect for what a huge solar array and a big bank of batteries can do after seeing what a relatively puny battery could actually do.
A standard AC system can't deliver even a percentage of that current.