I saw one case where an overcharging alternator may have been the cause of a battery exploding. A defective battery is another possibility. I wasn't around when the problem was sorted out so I never knew the actual cause. When solid state regulators fail they normally stop charging completely or sometimes charge low. I have heard of a couple cases where defective solid state regulators overcharged, but I have never seen that happen myself. On most alternators applying 12v to the right alternator wire, or grounding the right the alternator wire(depends on the alternator) will cause the alternator to produce full output. So, there's a chance defective/damaged wiring could cause overcharging.
I had an adjustable regulator which was set too high boil a battery dry. After that it was no good-the battery case was bowed out.
I saw 2 that did actually explode from over charging. The condition makes the battery boil and a lot of gases are trapped under the hood, hit the latch to open the hood and make a spark.. BOOM! 19V will cause headlights to blow when they're turned on. Any over charging condition even at a lower voltage will cause a dangerous gassing situation. Bob
Usually it boils them dry if it is overcharging on a continual basis. That is one of the indicators of an alternator that is overcharging along with bulbs that burn out too quickly. Having one explode is due to a spark setting off the gasses built up inside the battery due to charging and sometimes overcharging. You don't see it much with internal regulator alternators or ones with electronic regulators but it is pretty common with the older ones with mechanical regulators.
I have had them swell batteries when the voltage regulator took a dump. I have never had one explode one but i imagine that it could if it was a high amp alternator.
I too have seen them swell up but not explode. The fact that the battery swelled is enough proof to me that it could happen. I was just lucky enough it didn't.
The explosion comes when the gas produced by an overcharged battery meets an ignition source, like a spark.
Some claim that battery explosions are the result of a chain reaction of runaway pressure producing events. Maybe that can happen, but I have witnessed two battery explosions that were gas caused by gas: - Years ago I was working on a car where the battery blew up about 2 feet from my face. That was the result of the battery being charged with a loose cable clamp on the battery post. It turned out that loose connection is why the car was not running. That was a hydrogen explosion caused by the connection arcing. I could barely hear for 12+ hours and the battery was blown to pieces. - In another case I was getting out of a co-worker's car at night. The pavement was wet and reflective. As I got out I was looking down when the battery exploded. When it happened I saw a bright yellow light from inder the car. So again, a gas explosion.
My experience is the same as CutawayAl's, a customers battery exploded after recharging due to a poor connection at the battery post making an arc which ignited the hydrogen from the charging process. The suggestion that opening the hood ignited an explosion, by a different poster, is a little misguided. I don't ever recall seeing an electrically operated hood latch, ever. I would take a good look at all of the connections of the battery cables, as an ignition source. Please tell us the story that prompted this question. Are you looking for someone to blame for a battery explosion? ~Alden
it's the switch for the lamp on cars with a lamp under the hood, the battery gets overcharged.builds up a bunch of hydrogen and BOOM!
I had an old battery explode once in one of my cars. I had just started the car to move it, but I believe the explosion was due to multiple charge/discharge cycles to the point where gas had built up inside, and into pieces it went. There's a reason I don't like sealed batteries. Had acid everywhere after that one.
I got one of these,very easy to hide the LED somewhere where it's only visible when on, when battery voltage is normal it's green,then dims green until a status change, it warns of over and under voltage conditions instantly. gauge is nice but you don't always notice the gauge, the difference is you get used to the green color then when the color changes due to an issue you notice it right away http://signaldynamics.com/index.php...rtuemart&Itemid=77&vmcchk=1&Itemid=77#reviews
What I don't understand is how a battery can explode when it is full of hydrogen. With no air present an explosion wouldn't be possible. Maybe the lighter hydrogen can't displace all the heavier air out the top of the battery?
Lost, I am sorry, but I don't believe that either. The switches for the hood light, if they are mercury switches are sealed and if are of the sliding weight variety are at least enclosed. The switch isn't accuated on the hood opening to the first stop, it comes on when the hood is open pretty far. If someone has an experience otherwise I would be interested, but I think some are making theories without all the information. ~Alden
The caps are vented. I think ignition takes place outside the battery and then ignites the richer mix in the battery. Just like in a combustion chamber once ignition takes place, less then ideal mixtures can be burned. The reason this happens so rarely is the conditions must be just about perfect and are the result of multiple failures combining into one freak occurence. ~Alden
all cars don't have mercury switches, a lot of them have plunger type switches once enough hydrogen builds up it doesn't take much
Hydrogen is lighter than air. The hydrogen is at the top of the battery case and the air is below it. We had a guy checking the fluid level in a battery under a truck bed. He didn't have enough light to see so he used his cigarette lighter. He was lucky he didn't lose his eyesight.
good point when messing with a battery it seems stupid to some people, but a pair of those old science class splash proof goggles might save your eyes, they can and do sometimes explode. I've heard of more then one explosion that happened while fixing loose terminals, the goggles might not look cool, but it's hard to work on your car when you are blind, remember the hydrogen that is seeping up around that terminal and rising is right under the sparks caused by the loose terminal
The one I saw go up, opening the hood might have caused a spark from the metal to metal contact... just enough to set off the gases. Got no other explanation for it. All I know it was early in the morning and quite loud. Bob
they think now the coating on the skin started it, the hydrogen helped it along, the coating was basically thermite
If a battery survives overcharging and the case is swollen, at some point it will short out and 'probably' blow its top off. Most battery explosions I have been a victim of did so when I turned the ign swith on. peace
i have seen a battery that was over charged till it would no longer keep the car running, then the owner tried to boost the car and caused a spark when hooking up the cables to the now dead battery, BOOM, if he would of hooked up the dead battery first and then the good battery no BOOM, the entire top of the battery down below the top of the plates was gone.
The 2 I saw blow... one the hood was just cracked open a bit. Some of the pieces escaped and acid all over. The one with the hood up, the guy hooled up a Sun VAT-28 tester and it went. The guy was lucky he had glasses on. I just saw him with his head down doing the hook up, looked like a geyser of battery and fluid hit him in the face and chest. 2 of us grabbed him and doused him in a nearby utility sink. Off to the ER next.... someone called ahead and they were waiting for us at the door. They flushed out his eyes, washed him with something to neutralize the acid and of course treat his numerous cuts, all scratches more than anything. Bob
Here what happened to me! On the way home from the show in Yakima.Amp guage start showing overcharg 18 amps or so then started to spike up from there.Drove that way for a couple of hrs.It was really hot outside. I pulled a long hill and it went to the peg on the guauge.After cresting the hill I let off the throttle and within a block or so the battery popped as loud as a back fire .NO juice from there on.Roll back ride to Bozeman Mt.Next morning I pulled the battery and it looked like a small pumkin.Buldged all sides and the top cap was loose.This was a dry-gell cell battery.New alternator and battery and I was on my way.Really a weird experience