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Exploded battery in 2007 Jeep Compass

My daughter just called and said her battery exploded. It was hot (100) and battery was 4.5 years old. Told her to wipe it down with a baking soda solution and have AAA replace the battery for her. OK??

Sure. But just tell her to be careful what she touches under there. The battery acid is very strong and can burn her. I’d get a couple of boxes of baking soda, and shake them out all around the battery, compartment, and underside of the hood. Let it sit a bit, then rinse it off with a hose on LOW PRESSURE to prevent any splash back from getting on her. The acid could still be strong enough to burn after the baking soda application.

First, flood with low-pressure water…Then neutralize with the baking soda… Then rinse again…Then, replace battery…

I agree with caddyman. Water does an excellent initial job of neutralizing battery acid, and the baking soda solution will take care of the rest. The first thing she should have done is hosed off the engine compartment to prevent the acid from eating away at anything, but she probably didn’t know that (this is also what you would want to do if you got battery acid on you. Water will rinse it away and make it stop burning, so long as it hasn’t done any significant tissue damage).

On a slightly different note, what caused the battery to explode? This isn’t a normal or common occurrence.


What piter_devries means to say is that she absolutely needs to wear eye protection while doing any cleanup work. It doesn’t take much acid to blind someone.

When a battery becomes deeply discharged it produces hydrogen gas. This hydrogen gas then accumulates under the hood at the battery area. If a spark is produced when attempting to start the engine it ignites the hydrogen gas and the battery explodes.

That’s why they say to make the last ground connection somewhere on the engine away from the battery on a jump started vehicle in case there’s hydrogen gas from the discharged battery.


No idea why battery exploded. Dealer can’t get to it til next week! “tester” - Didn’t explode when starting the car, she had just driven home and turned it off. Then boom! Any opinions on what happened?

Her voltage regulator could have gone bad and allowed the alternator voltage to go way too high. That would overcharge the battery, also generating hydrogen gas and a lot of heat. Before putting in a new battery, make sure they check the charging system.

No opinions, but I want to echo the need for eye protection. I was in for an eye exam last month, and the Dr had one of those videos in the waiting room. Guess what the most common accidental cause of blindness is - car battery related issues! Ack! I never would have guessed, but I figure I would pass it on.

I never would have guessed battery related issues as the most common accidental cause of blindness either. Great post, my lament the inability to rate posts, so I have to add to the clutter. Safety glasses are dorky, but looking like a dork for a few minutes beats being blind for life.

It’s probably just bad luck. When I was younger, my dad had his car in the shop for various ailments. The battery was replaced. While the tech was carrying the old battery away from the car, it exploded–it apparently had an internal problem. I’d wash everything under the hood that looks like it got blasted with ‘battery juice’ with a solution of baking soda and water, heavy on the baking soda, and then rinse it thoroughly. Avoid touching anything and/or wash your hands thoroughly after. Safety goggles would be a good idea.

No need for the dealer to replace the battery unless there is a warranty issue. Just get one from a local parts store or independent mechanic. You will pay a lot less not going to the dealer for this, and the new battery will be just as good.

“Safety glasses are dorky, but looking like a dork for a few minutes beats being blind for life.”

Tell that to your surgeon or your rangemaster. Safety glasses are cool, and owning your own is even cooler.