What Could Cause this Explosion?

[Carl Eyman]

Saturday I was standing on my son's front porch bidding goodbye to his guests. Suddenly there was a BANG from the rear of the house. My grandson had gone to the rear of the driveway to start the car. When I got back there he was standing by the car with the hood raised. The battery had blown up. The cell plugs were all gone and a piece was blown out of the top. Needless to say there was battery acid all over the place. The car had not been running for several hours; so one would suspect any hydrogen gnerated from charging the battery would have long since dissapated. There was no sign of a source for a spark. That is battery cables were tight on the posts, no loose wire connections, and no signs of burnt insulation from a short. The explosion happened before the engine started. Grandson said he did not think the engine had turned over as much as to fire more than one cylinder.

Anybody got an idea? Will we all have to go to magnetos and hand cranks now to be safe?

[Brad Olson]

Can't help as to the source of the explosion, but go and buy a bunch of baking soda and use it to neutralize all of the acid in the engine compartment.

If not the acid will start coroding things.

When I had a battery leak in my engine compartment I did this at a carwash and it worked pretty good.

[Ken Werner]

I dunno Carl, but this is a good one for the Car Talk guys, click and clack.
Go to cartalk.com

Ken

[Mitchell Andrus]

Frozen cells will sometimes blow when charged. If not frozen, 'dunno.

[Jack Dickey]

I drive an 18 wheeler and while its not Common , it's not uncommon either ..
Why ?? I dunno .. It happens ..

[Steve Clardy]

Internal battery short

[JayStPeter]

That's why you don't hook the negative to the battery when jump starting. Bad battery ... spark ... bang.
I had one blow on a charger in my garage once. It was 9 years old and I was pushing to see exactly how long it would last. I wasn't using a "smart" charger and must've overcharged it.

[Jason Roehl]

I'll second the internal short--must have been near the top where the hydrogen gas comes off the acid, and a vent (design or crack) let in some oxygen. Not to mention, there's a LOT of current at startup. 12V x 500A = 6000W. That's a lot of heat to be dissipated.

[Jerry Clark]

Probably an internal short-- but if the electrolyte level is low, it will allow more gases to accumulate in the top of the battery-- makes for more dangerous explosion.:eek: Also more prone to short! Keep the level full!:cool:

[Jack Dickey]

I spoke to our lead mechanic today and he agreed pretty much with low electrolyte level and/or internal short ..

[Dave Mcintire]

If the battery exploded when he tried to start the car it may have been a short external to the battery (not internal). For instance in the starting solenoid, starter or wires to these parts. In this case the short would not have been imposed on the battery until it was attempted to start the car, which seems like what you post was saying.

[Carl Eyman]

Dave, and others:

The reason an external short seems out is there was no sign of burnt insulation in the area and when a new battery was put in everything worked a-OK.

[Dennis Peacock]

I'd have to agree with an internal short. Car batteries make me nervous sometimes. :)