Wow reckless, that's amazing your eyes were not harmed. Could have been so much worse. Seems your extensor tendons were extremely close to being cut from the photo.

It's good you posted that story since many may not be aware of the dangers of hydrogen gas. As a youngster nerd of 13 - 15, I had a rather large chemistry lab at home and played around with hydrogen gas. I would fill garbage bags with it and attach stuff to them and watch them drift away, amazing the other kids in the neighborhood. And then sometimes,....we'd light the bag and it was quite a boom but harmless because the bag was so easy to rip and the hydrogen had lots of room to expand easily. IIRC, I would put Zinc pellets in a flask and introduce H2SO4.

But batteries can indeed explode with great force. Considering the volatile gas inside and the amount of current involved, isn't it amazing battery explosions are so rare?

Yes I was indeed very lucky that my arm just happened to shield my eyes! It still gives me the shivers to think how different my life would have been had I lost my sight all those years ago.

 

I was walking to the parking lot after work some years ago and heard a loud "pop".
I located the source and it was from an exploding battery that a couple of guys were trying to jump start.
Fortunately, neither of them were injured by the exploding parts or the acid.
Don't know if they connected it backwards or if it was just from the sparks of the connection.
But it's a note of caution to be very careful when jump starting a vehicle.

I've seen some jumper cables that have a switch in series with one of the wires and about the midpoint, so you can complete the connection when you are well away from the batteries.

 

I was sitting in a 69 GTO...in neutral, idling.......talking to my uncle on the sidewalk........and kaboom!

A very loud kaboom. GTO engine was dead.......went to front and looked under the grill......and lots of water dripping to ground from all over the engine compartment.

Raise the hood.......and the battery was all over the engine. Spent a couple of hours flushing it out. Flushed it out immediately right there on the street. No hazmat police back then. Lots of impact scaring in compartment. Plastic and lead shrapnel.

New battery and my buddy sold the car that I had borrowed. I felt terrible. He loved that car.

He use to kid me saying that if I hadn't blew up his GTO.......he would have never had his Super Bee.

He was strictly a dodge man after that Hemi.

 

I was sitting in a 69 GTO...in neutral, idling.......talking to my uncle on the sidewalk........and kaboom!

A very loud kaboom. GTO engine was dead.......went to front and looked under the grill......and lots of water dripping to ground from all over the engine compartment.

Raise the hood.......and the battery was all over the engine. Spent a couple of hours flushing it out. Flushed it out immediately right there on the street. No hazmat police back then. Lots of impact scaring in compartment. Plastic and lead shrapnel.

New battery and my buddy sold the car that I had borrowed. I felt terrible. He loved that car.

He use to kid me saying that if I hadn't blew up his GTO.......he would have never had his Super Bee.

He was strictly a dodge man after that Hemi.

 

wow. It's so rare to hear of someone actually experiencing an exploding battery.

I find it just amazing that far more people aren't injured / killed in battery mishaps.
There's an awful lot of energy stored in them. And people who have no clue grab a set up jumper cables and dive in, hooking them up backwards, shorting them to the frame, smoking etc etc.

Millions of people have Lithium Ion batteries stuck to our heads every day in the form of blue tooth headsets and cell phones etc....not as powerful as a car battery but they can (and do) sometimes explode and cause injuries. Not to mention fires.

Every though about how many potential cabin fires there are when you fly? The environment is oxygen rich and there you have maybe hundreds of lithium ion batteries in laptop and cellphones all around you. Some day after the Lithium Ion battery era passes, people will look back in horror that there was a time when people had them with them in passenger flights.

This thread has me considering a switch to AGM batteries

 

I am assuming you are asking about the cause-
Two possible causes:
One, that the battery was leaking Hydrogen gas (various reasons), and exploded due to localized ignition (the gas was collecting, and concentration got high enough to explode), rather unlikely for ordinary usage or Two: The charging circuit was acting up, and was overcharging the battery to the point where it exploded, probably with gas production, and overheating. This could be because the Alternator voltage setting went off, (circuit failure), and it pumped excessive current into the battery, while attempting to keep the voltage at set point. Because the battery exploded, and not other things, it was clear that the battery and charging circuit was the most likely culprit. Also, very old batteries can corrode to the point where internal connections get so thin, they can heat up and even melt and arc with high current flow.

 

Also, very old batteries can corrode to the point where internal connections get so thin, they can heat up and even melt and arc with high current flow.

This was an issue when they first started changing over from Lead/Antimony plates to Lead/Calcium plates. The inter-cell welds would fail causing intermittent contact between cells. With a combination of the gas produced by charging/overcharging and a bit of vibration ----- boom. [Early in my electronics career, I worked for a major automotive/industrial battery manufacturer.]

 

Every though about how many potential cabin fires there are when you fly? The environment is oxygen rich...

Why do you say that?
The cabin air is just outside air compressed to 11-12psi, equivalent to an altitude of six to eight thousand feet.
At that pressure the available oxygen is less than at sea level, so a fire would actually burn less fiercely.

 

But none of these, mine included, come from the battery getting too hot and exploding. Like the dragon claims.

 

Why do you say that?
The cabin air is just outside air compressed to 11-12psi, equivalent to an altitude of six to eight thousand feet.
At that pressure the available oxygen is less than at sea level, so a fire would actually burn less fiercely.

right right.....forgot about that. Haven't been on a commercial plane in 15+ years

Got any thoughts on AGM batteries?

 

Got any thoughts on AGM batteries?

They are sealed so that lessens the chance of an explosion.
And they have less free acid to spread if they do explode.

 

Sure!
It's technically called acid stratification.
https://batteryuniversity.com/learn/article/water_loss_acid_stratification_and_surface_charge

The specific gravity of Sulfuric acid is 1.85.
The specific gravity of water is 1

So even though Sulfuric acid is soluble in water, it tends to concentrate at the bottom if undisturbed for a period of time

At least, that's what I recall to the best of my aging gray matter.
A "Real" chemist will come along and set me straight.

Having just searched this there appears to be something in what you say ... I am a pretty good chemist and I find it hard to believe this occurs by itself ... it may result because the cells are topped up with water from above , and incomplete mixing occurs.

Consider a beaker of water ... 98% sulfuric acid is slowly added with stirring... a great deal of heat is given off ! If left standing it's inconceivable the acid would tend to settle out at the bottom , you could then mix it and get more heat ... It would break the laws of thermodynamics and entropy.

 

Having just searched this there appears to be something in what you say ... I am a pretty good chemist and I find it hard to believe this occurs by itself ... it may result because the cells are topped up with water from above , and incomplete mixing occurs.

Consider a beaker of water ... 98% sulfuric acid is slowly added with stirring... a great deal of heat is given off ! If left standing it's inconceivable the acid would tend to settle out at the bottom , you could then mix it and get more heat ... It would break the laws of thermodynamics and entropy.

Not being a chemist myself, I think Battery University says it happens due to the process of the lead / lead sulfating process in SLA batteries.
I would think this link could explain acid stratification better.....
https://batteryuniversity.com/learn/article/water_loss_acid_stratification_and_surface_charge

 

Not being a chemist myself, I think Battery University says it happens due to the process of the lead / lead sulfating process in SLA batteries.
I would think this link could explain acid stratification better.....
https://batteryuniversity.com/learn/article/water_loss_acid_stratification_and_surface_charge

Yes I did see that article ... battery university is a very good site , but I was not convinced .....

I would caution against believing something because it's widely accepted . There was a similar myth about a supposed 'memory effect' in NiMH and NiCd cells, this was believed for over a decade , now it is not ( see here ... http://www.greenbatteries.com/nimh-battery-faq/#NiCd memory )

I still am not 100% certain about acid stratification , I've asked the question on a physics forum and will report back .... But my bones tell me it cannot happen ... It's like saying the carbon dioxide in the atmosphere will sink because it's heavier, this doesn't happen ... once soluble elements are mixed together , they can't separate out.

 

I still am not 100% certain about acid stratification , I've asked the question on a physics forum and will report back .... But my bones tell me it cannot happen ... It's like saying the carbon dioxide in the atmosphere will sink because it's heavier, this doesn't happen ... once soluble elements are mixed together , they can't separate out.

You seem to be forgetting the electro-chemical part of the battery reaction, something that doesn't take place with the carbon dioxide in the atmosphere.

 

You seem to be forgetting the electro-chemical part of the battery reaction, something that doesn't take place with the carbon dioxide in the atmosphere.

Before we started digging up coal, most of the carbon dioxide came from respiration at or near ground level. And, if it's important, that's an electro-chemical reaction too.

 

Not being a chemist myself, I think Battery University says it happens due to the process of the lead / lead sulfating process in SLA batteries.
I would think this link could explain acid stratification better.....
https://batteryuniversity.com/learn/article/water_loss_acid_stratification_and_surface_charge

Only remembering my college chemistry, but when you stir it the first time, what is generating the heat? I thought that a chemical process occurred, resulting in fewer reactions available the second time you stir the mixture. Hence, less energy available for the second stirring. Entropy is conserved. Might be the wrong word; I hope you know what I mean.

 

There was a similar myth about a supposed 'memory effect' in NiMH and NiCd cells, this was believed for over a decade , now it is not

That article does state that NiCds, and to a lesser extent NiMH cells do have "voltage depletion or voltage depression phenomenon."
"If a NiCd battery is repeatedly charged after it has only been partially discharged it will develop a lower voltage and a lower capacity. "
It may technically not be a "memory effect" (although it seems like that to me), it is not a myth.

 

When I was working for a company that made NiCd powered products I ran some tests trying to show up a 'memory' effect but I found nothing. When I checked the batteries returned by customers as suffering this effect they generally had a shorted cell and this is usually the result of over-discharge resulting in reverse charging of the weakest cell.

 

I have seen it once, a battery exploding. The only result was the acid burned winter coat and bad spots on the cars fender paint. But this was from trying to jump a frozen car battery. Not from charging one with a dead cell.

This is off topic but I remember it like it was yesterday and it was 52 years ago.

Like many kids at the time, during 1966, when I was 16 I worked at a local gas station. Batteries came less any electrolyte and we would add the electrolyte, sulfuric acid, and then charge the batteries. I had just finished charging a brand new battery and started to install it. There is a good reason to connect the Positive post first. I knew that but didn't. I stupidly connected the negative post. The battery was still out gassing hydrogen. While connecting the positive post my wrench bumped the car chassis. I managed to have the top of the battery meet part of my head and got a good dose of acid in my face. Thank God a co-worker got me to the deep sink and hosed my face and eyes down. The only damage. other than the battery was my ego and pride. Lucky does not even describe what I was. To this day about 52 years later, every time I have installed or removed a battery I remember that moment. I also remember it when I read threads like this.

The "S" in SLA is a pretty important thing.

Ron