Car fire started by button cell battery?

[coppercone2]

and what point are you making, because a regular alkaline battery can start a fire too. their comparable because of the PTC




they even have that trick where you use a gum wrapper to make a AA battery work with a smaller cell. wow that can be a bad idea huh

[BrianHG]

Nile red opens an AA lithium battery: (Yes, it burst into flames and even explodes when he drops it in water...)

https://www.youtube.com/shorts/yGDkiUAwxRs

[AVGresponding]

There aren't any primary cells, whether lithium, silver oxide, or alkaline, of this genaral size, that are capable of starting a fire by means of a short circuit. Any wire small enough to be fused by the currents these can produce would be too tiny and have too little thermal mass and therefore energy to ignite anything besides possibly black powder or something similar.

Saft make primary lithiums with rated discharge current (pulsed) greater than 20A. That would easily start a fire, so you'll need to walk back the bold claim of all primary lithium to something significantly smaller like: consumer button cells.

Even energizer will happily point out the significant short circuit currents available in their consumer AA's:
https://data.energizer.com/pdfs/lithiuml91l92_appman.pdf
A few dozen joules? yep that's some significant hazard.

Read what I actually wrote.

[AVGresponding]

Most of what has been posted since my post reply #9 has NO relevance to this subject.

Siwastija mentions "a small piece of nichrome wire, and wrap it around something very flammable, and maybe you can have a fire."
How is this relevant? This scenario is a deliberate attempt to cause a fire, not an accident. You think these e-books have nichrome wire wrapped around flammable materials in them?!?

Other people talk about large, specialist primary cells or AA's or AAA's. None of this has ANY relevance to button/coin cells. The internal cell resistance and capacity is different by orders of magnitude.

[Someone]

There aren't any primary cells, whether lithium, silver oxide, or alkaline, of this genaral size, that are capable of starting a fire by means of a short circuit. Any wire small enough to be fused by the currents these can produce would be too tiny and have too little thermal mass and therefore energy to ignite anything besides possibly black powder or something similar.

Saft make primary lithiums with rated discharge current (pulsed) greater than 20A. That would easily start a fire, so you'll need to walk back the bold claim of all primary lithium to something significantly smaller like: consumer button cells.

Even energizer will happily point out the significant short circuit currents available in their consumer AA's:
https://data.energizer.com/pdfs/lithiuml91l92_appman.pdf
A few dozen joules? yep that's some significant hazard.

Read what I actually wrote.

Reading would be easier if you didn't use a low contrast font colour....

The one that was mentioned in the article uses 3 AG13/LR44 (alkaline) cells.  I've never heard of those catching fire or causing a fire (but I've never tried shorting one).  Of course, the fire department unhelpfully did not say if that's the actual book that was found.

They don't, the internal cell resistance is far too high for that kind of current. It's a relatively cheap and easy experiment to do yourself.

There aren't any primary cells, whether lithium, silver oxide, or alkaline, of this genaral size, that are capable of starting a fire by means of a short circuit. Any wire small enough to be fused by the currents these can produce would be too tiny and have too little thermal mass and therefore energy to ignite anything besides possibly black powder or something similar. Certainly not plastic tat cases.

3 x LR44 or AG13, so a 1/3 to a 1/4 of an AA which is still in the plausible range given the above consumer AA's have more than enough energy to produce fire (despite protection).

[MK14]

It seems that the experts are saying those AG13 batteries, can be a fire hazard.
From the link below:

Experts say alkaline batteries can ignite if the posts come into contact with metal and heat builds.

Source of picture (publishers of the book, involved with this fire incident):
https://www.wbtv.com/2024/08/28/batteries-childrens-book-that-caused-burke-county-minivan-fire-arent-lithium-publisher-says/

[AVGresponding]

Reading would be easier if you didn't use a low contrast font colour....

People read what they want to read and disregard the rest.

3 x LR44 or AG13, so a 1/3 to a 1/4 of an AA which is still in the plausible range given the above consumer AA's have more than enough energy to produce fire (despite protection).

"X can start a fire, so 1/4-1/3X can also start a fire". This is nonsensical.

It seems that the experts are saying those AG13 batteries, can be a fire hazard.
From the link below:

Experts say alkaline batteries can ignite if the posts come into contact with metal and heat builds.

What experts? Give links to published, peer reviewed research.

[MK14]

It seems that the experts are saying those AG13 batteries, can be a fire hazard.
From the link below:

Experts say alkaline batteries can ignite if the posts come into contact with metal and heat builds.

What experts? Give links to published, peer reviewed research.

Well that linked to article, seems to also say, something on the lines of, they are continuing to investigate the cause of the fire.

So, I'm happy that the American system, has chosen appropriate expert(s), and are professionally investigating the cause of the fire.

If on the other hand, that is not good enough for others, such as yourself.  Then feel free to reach out to the American authorities, and/or other people involved, in this case, and argue the point with them.

I'd suggest at least giving them the time to complete their work, and publish or announce their results, rather than hassling them, at such an early stage of their inquiries.

[MK14]

I have a new, super wild, possible theory, of what might have happened.  Partly based, on something I read on the internet.

The battery set ran out, then instead of replacing all three AG13 batteries, they tried replacing ONLY 2 of them, leaving one old cell in place.  The device (book) appeared to work ok, so they stopped adding any more batteries (or had run out of new ones).  Alternatively, a battery was the wrong way round, assuming it could still make contact, with the battery terminals, in that case? (off-hand, I don't think it would, but maybe it had flimsy battery contacts, which can connect in both orientations?)

The run down, old remaining AG13 cell, then became super discharged, and within its sealed cell, built up a big pressure of gases (possibly Hydrogen).

At some point, the gas pressure was too much for the sealed and expired AG13 battery, which then exploded.  The release of a high percentage of compressed Hydrogen gas, then found an ignition source (possibly via one of the remaining two good batteries, during the explosion), which then ignited stuff, causing the fire.

[tszaboo]

Reading would be easier if you didn't use a low contrast font colour....

People read what they want to read and disregard the rest.

3 x LR44 or AG13, so a 1/3 to a 1/4 of an AA which is still in the plausible range given the above consumer AA's have more than enough energy to produce fire (despite protection).

"X can start a fire, so 1/4-1/3X can also start a fire". This is nonsensical.

It seems that the experts are saying those AG13 batteries, can be a fire hazard.
From the link below:

Experts say alkaline batteries can ignite if the posts come into contact with metal and heat builds.

What experts? Give links to published, peer reviewed research.

I cannot find UN 38.1 documents for AG13 batteries after a quick search. That would describe the short circuit conditions of the battery
Nor ESR. I found one claim that it's ~5 Ohm, so let's work with that.
4.5V 15 Ohm source means that there is 337mW power available for the electronics. I can make electronics safe with this much power, it's very low. Meaning I can design you eg. a sensor that's mounted inside a gas tank, and it's going to be safe. But let's work from the other way.
It's a children book with built in battery. Paper's autoignition temperature is ~230C. Probably they just chucked the electronics in between paper pieces, with some loose wires, and it's made from single side phenol PCB. And made a mistake while assembling it, wire is not properly isolated. Take a small part, like an 0402 resistor, apply 300mW to it. It goes from 70C to 150C with 63mW, about 1.2K/mW, suddenly your part is over 400 Celsius hot, enough to set paper on fire.

[tom66]

I cannot find UN 38.1 documents for AG13 batteries after a quick search. That would describe the short circuit conditions of the battery
Nor ESR. I found one claim that it's ~5 Ohm, so let's work with that.
4.5V 15 Ohm source means that there is 337mW power available for the electronics. I can make electronics safe with this much power, it's very low. Meaning I can design you eg. a sensor that's mounted inside a gas tank, and it's going to be safe. But let's work from the other way.
It's a children book with built in battery. Paper's autoignition temperature is ~230C. Probably they just chucked the electronics in between paper pieces, with some loose wires, and it's made from single side phenol PCB. And made a mistake while assembling it, wire is not properly isolated. Take a small part, like an 0402 resistor, apply 300mW to it. It goes from 70C to 150C with 63mW, about 1.2K/mW, suddenly your part is over 400 Celsius hot, enough to set paper on fire.

You are neglecting the thermal loading of the paper on the resistor.  I would be surprised if the paper could itself get to 400C in a local spot to support combustion with that resistor alone. 

[Andy Chee]

I would've thought this battery fire would've been relatively simple to replicate by someone on YouTube by now.

[tszaboo]

I cannot find UN 38.1 documents for AG13 batteries after a quick search. That would describe the short circuit conditions of the battery
Nor ESR. I found one claim that it's ~5 Ohm, so let's work with that.
4.5V 15 Ohm source means that there is 337mW power available for the electronics. I can make electronics safe with this much power, it's very low. Meaning I can design you eg. a sensor that's mounted inside a gas tank, and it's going to be safe. But let's work from the other way.
It's a children book with built in battery. Paper's autoignition temperature is ~230C. Probably they just chucked the electronics in between paper pieces, with some loose wires, and it's made from single side phenol PCB. And made a mistake while assembling it, wire is not properly isolated. Take a small part, like an 0402 resistor, apply 300mW to it. It goes from 70C to 150C with 63mW, about 1.2K/mW, suddenly your part is over 400 Celsius hot, enough to set paper on fire.

You are neglecting the thermal loading of the paper on the resistor.  I would be surprised if the paper could itself get to 400C in a local spot to support combustion with that resistor alone.

I'm ignoring a lot of things here, because not many things are known about the construction or the battery itself.
I'm only pointing it out that it's not impossible.

[mikeselectricstuff]

I just measured the short-circuit current of a new LR44 at 0.7A - not totally implausaible that this ( or 2-3 of them) could start a fire

[55pilot]

I just measured the short-circuit current of a new LR44 at 0.7A - not totally implausaible that this ( or 2-3 of them) could start a fire

That is an ESR of about 2 Ohms, which is almost exactly what the graph on Page 2 of the Duracell spec, posted earlier, predicts.

Some people are incorrectly quoting the graph as showing an ESR of 5 Ohms. What that graph is actually showing is the voltage when loaded by various resistors, the smallest of which is 5 Ohms. The 0.45V drop across the ESR and 1.1V across the 5 Ohm indicates an ESR of about 2 Ohms.

[tszaboo]

I just measured the short-circuit current of a new LR44 at 0.7A - not totally implausaible that this ( or 2-3 of them) could start a fire

That is an ESR of about 2 Ohms, which is almost exactly what the graph on Page 2 of the Duracell spec, posted earlier, predicts.

Some people are incorrectly quoting the graph as showing an ESR of 5 Ohms. What that graph is actually showing is the voltage when loaded by various resistors, the smallest of which is 5 Ohms. The 0.45V drop across the ESR and 1.1V across the 5 Ohm indicates an ESR of about 2 Ohms.

What datasheet?

[MK14]

Over on a Chemistry related forum, there seem to be a large number of reports, of these types of batteries, exploding.  There are so many reports by different posters, it makes me wonder if there is something to it.
So, if as I mentioned earlier, the gas is mainly Hydrogen (I'm NOT sure), that could explain a fire, as Hydrogen, can very easily ignite and then potentially set fire to stuff.

I discount one of the reports, where the battery exploded when they were soldering to it.   

Here:
https://www.reddit.com/r/chemistry/comments/a63dy3/lr44_just_exploded_2018/

[Siwastaja]

I'm only pointing it out that it's not impossible.

I agree. It's entirely possible that the button cell batteries are the cause, but it is more probable that the cause is actually something else.

It would be most interesting to hear about why anyone thinks the cause is the battery and not something else. Do they have any basis for it, or is it just an assumption "battery was present, and batteries are dangerous, therefore must have been the battery"?

[Phil1977]

Over on a Chemistry related forum, there seem to be a large number of reports, of these types of batteries, exploding.  There are so many reports by different posters, it makes me wonder if there is something to it.
So, if as I mentioned earlier, the gas is mainly Hydrogen (I'm NOT sure), that could explain a fire, as Hydrogen, can very easily ignite and then potentially set fire to stuff.

I discount one of the reports, where the battery exploded when they were soldering to it.   

Here:
https://www.reddit.com/r/chemistry/comments/a63dy3/lr44_just_exploded_2018/

Interesting reports... But these batteries seem to have exploded without fire, probably they just build up pressure until the housing popped.

Hydrogen is usually not a big danger - yes it easily ignites but it also diffuses away from its source in no time. And if a small volume of hydrogen burns then it´s just a very short flash, very hard to imagine that this lights up a book. Lead acid batteries generate quite a large amount of hydrogen/oxygen mixture, and its danger is much more spraying around the sulphuric acid than setting anything on fire.

I think its not common but also not impossible that an overloaded 0402 resistor wrapped in paper sets something on fire. Heated paper really is a good fire starter.

[MK14]

Interesting reports... But these batteries seem to have exploded without fire, probably they just build up pressure until the housing popped.

Hydrogen is usually not a big danger - yes it easily ignites but it also diffuses away from its source in no time. And if a small volume of hydrogen burns then it´s just a very short flash, very hard to imagine that this lights up a book. Lead acid batteries generate quite a large amount of hydrogen/oxygen mixture, and its danger is much more spraying around the sulphuric acid than setting anything on fire.

I think its not common but also not impossible that an overloaded 0402 resistor wrapped in paper sets something on fire. Heated paper really is a good fire starter.

Thanks, that is a very thoughtful and good post!

Unfortunately, I think we are (or at least me), like back seat drivers, or it is all too easy to comment, when sitting at ones couch.

If any entity gets serious about investigating this fire incident.  They would need to process all the available evidence and information.

As regards the batteries, being involved.

There are lots of possible ways (many already mentioned in this thread).  Such as electrical over-heating, setting fire to something, a Hydrogen explosion (as you said, the vast bulk of the time, it does not set anything on fire, but there is a small or tiny risk, that maybe it could or did), even theories that the same Chinese battery factory, handles (makes) Lithium batteries as well, and such material ended up in the fire starting battery cells.

There are also many other causes of car fires, including its electrical wiring, fuel leaks catching fire, a fire underneath the car for some reason (almost certainly would have been noticed and caused different fire effects), the owners setting the car on fire for reasons (such as insurance fraud), etc.

Hopefully and if necessary.  The investigators can get any research professionally done by experts, as necessary, if they deem it necessary.

As regards this thread, my gut feeling (I could easily be wrong), LR44 batteries are too weak and low capacity, electrically speaking, to readily (ignoring a super-rare accident), heat stuff up (or itself), enough to pose a serious fire risk.

On the other hand, (as already mentioned), 700 milliamps, is more than I was expecting, from such a tiny cell, especially with it being Alkaline.  Even much bigger Alkaline cells, don't seem to have anything like as high short-circuit currents (IIRC, I managed to get around 5 .. 10 Amps, from a fresh Alkaline C cell, of decent brand), compared to most rechargeable battery types, such as Lead-acid batteries, which give out crazy amounts of current, if necessary.

EDIT: Much editing, lots of typos and made shorter.

[MK14]

Here (at end of the post) is a tear-down and demonstration video, of around 6.5 minutes long, of what seems to be a similar type of electronic button/sound toddler book.

Apart from the possibility of the somewhat flimsy looking metal battery tabs, perhaps being able to short out, the battery(s).  I can't see any immediate/easy fire risk.

The only real component, is a black epoxy blob style chip, on a PCB, no resistors, just a speaker and the buttons, on some kind of flexible PCB style setup.  Maybe a small decoupling capacitor, I didn't see it, but it was on the hand drawn schematic, later in the video.

But it is possible, the actual book, was significantly different inside, I don't know.

[tszaboo]

I can't see any immediate/easy fire risk.

Hint: One of them is black, the other red. They go directly to the battery.
Also these things get chewed on, thrown around, and who knows what else.

[MK14]

I can't see any immediate/easy fire risk.

Hint: One of them is black, the other red. They go directly to the battery.
Also these things get chewed on, thrown around, and who knows what else.

But they would have to break through the plastic case, break the insulation of both wires, then the wires would need to contact each other.  Even then, I'm not sure such a modest current (maybe 0.7 Amps), could readily cause a fire.

On the other hand, a 200 milliamp bulb, at perhaps 4.5 Volts, can glow almost white hot, inside its sealed glass envelope.

[SiliconWizard]

I haven't followed the latest posts but there seems to be a lot of guesses and maybes.

In the end, I am unsure of exactly what type of "button cell battery" this is all about.
I have personally never seen or directly heard of a standard Lithium primary button cell battery exploding.
But - I certainly have for Zn-air batteries (the ones used in particular in hearind aids) which are a completely different chemistry and hold a lot more capacity too.

[thm_w]

In the end, I am unsure of exactly what type of "button cell battery" this is all about.

AG13/LR44 as was explained above.

I have personally never seen or directly heard of a standard Lithium primary button cell battery exploding.

They absolutely do and I've mentioned it here a few times, I've seen it myself twice on major brands (Renata). Its just incredibly uncommon on quality brands (this was 2 out of 10,000+ cells).
https://www.google.com/search?q=cr2032+blown