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This month the subject is batteries

My digital version of Motor magazine arrived today and this months main topic is batteries. I have a question and some info,first the question. Would you expect that your independant shop to do a starting/ charging system test if you simply asked that your car be given a “look over”?. I say yes, and the test should include a scope view of the electrical activity at the battery.

Now the info. A battery with reduced capacitance will show the same wave form as one that is being charged by an alternator with a bad diode (too much AC in the DC). The most startling fact, the number 3 reason for accidental blindness in males over the age of 15 is caused by a battery that explodes during the hook up sequence to make a jump possible. I never realised that battery explosions were this commom. I have only seen one in my life and it was a reverse polarity event, blew a crack right up the side of the battery

A few years back, I gave a jump to a friend’s Datsun B210 with a 69 Buick Skylark. I connected the cables to the B210 (correctly) and stepped away from the car. A few seconds later the caps blew off the battery spraying acid all over the hood area.

Ed B.

For our readers, please be very careful when giving a jump. It seems like it could turn out to be a very dangerous activity, even when you do all correctly. It is so easy to dismiss the possibility of bad things happening durning a jump because we all have done so many that went smoothly, but pay attention and look away when that final connection is made.

This Motor magazine suggested using a full 12v source for memory retention when changing out a battery. They suggested using a jump box for the temp. power. I think a jump box would be a great Christmas gift for just about anyone. Making youself self sufficient when out on the road is not a bad goal.

Battery explosions occur when the battery is deeply discharged, and when the final connection to the battery is made at the negitive battery terminal. A deeply discharged battery produces hydrogen gas. And if the final connection to the battery is made at the negative terminal and it creates a spark the battery can explode. That’s why they always recommend that the final connection be made somewhere on the engine away from the battery to prevent an explosion.


Battery blowups are something that I have warned people about since I have been commenting here. Finally, a magazine says it and people will believe it. So, let’s all buy goggles as a minimum precaution and protect ourselves. There are gloves, aprons, face shields and water bottles that might also help.

When you’re trying to be helpful, you might have the goggles in the trunk. That idea will get me to Big Lots or The Dollar Tree to buy my second pair. No need to have a good idea and just let it sound good.

Wouldn’t it make sense to hook up the dead battery first? That way you shouldn’t have to worry about gloves, aprons, face shield and water bottles.

Had a battery explode on me too. Since then, I refuse to allow my kids to have access to jumper cables but made sure they had a triple A card. I now wince behind goggles and wear rubber gloves and have rinse water access every time I hook up the charger on my boats or clean the terminals on any battery. Keep them encased and treat them with more respect then we do, always. If you must jump, use a low powered jumper battery.

If that doesn’t work,
get someone whose getting paid to do it and much younger whose healing time is a lower %
of the time they have yet to live, my basic philosophy in doing anything dangerous, including roofing etc.

And if the condition that causes the battery to explode is a case of reversed polarity hook-up do you just go and buy a new set of eyes with the money you saved on not buying eye protection right from the beginning? If you cannot be bothered to wear eye protection you will in some shops not be asked to come back to work as wearing your eye protrction can be a condition of employment . If you insist on not wearing eye protection while working at home, at least turn your head when making the final connection. Why I take the time to explain to a person who doesn’t engage brain before pressing keyboard is simply to once again point out that you have absolutely no automotive experience and simply want to cause conflict within the Forum.

Battery explosions are not only limited to deeply discharged batteries or reversed polarity hookups. As long as the battery has any concentration of hydrogen and oxygen (a byproduct of the charging process) hovering at its surface, it is vulnerable to exploding.

Reversed polarity or not, the last (4th) connection when using jumper cables will produce a spark. Avoid having that spark be near the top of a battery.

I had a battery explode on me when I was 19. My face was showered with acid, sprayed with shrapnel of plastic from the top of the battery, and it sounded like an M80 went off next to my ear.

Several Of The Newer Cars In Our Family Fleet Have Their Batteries “Buried” And Are Equipped With Underhood, Covered (+), Labeled Remote Jumper Connections.

I always thought it was a pain for the owner to have the battery buried in there, but maybe this set-up is designed to both utilize space and to prevent pain for the owner.