Lithium Ion Batteries and the Phenomenon of Thermal Runaway

For an anology, think of Thermal Runaway as an extremely scaled down version of a "meltdown" in a nuclear reactor - minus the radioactivity. Thermal Runaway, in a nutshell, is when a battery creates sooo much heat so rapidly that said heat is unable to dissipate in the short amount of time it is created leading to an uncontrollable & unstoppable fire that can occur so rapidly as to mimic an explosion. Of course this "explosion"/fire is prolly happening inside your vehicle............

Links:
https://www.rutronik.com/article/de...tteries-how-can-thermal-runaway-be-prevented/
https://dragonflyenergy.com/thermal-runaway/
https://www.batterypoweronline.com/...g-the-fundamentals-to-ensure-safer-batteries/
Discuss..........
INTJohn

It is an extremely rare event

RvNaut said:

It is an extremely rare event

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I’ve been unable to source any reliable data regarding the frequency of such an event like Thermal Runaway as it pertains to lithium ion batteries and the prevention of thermal runaway seems primarily to be due to external safety measures rather than any direct safety factors inherent to lithium ion batteries themselves.

So, I’m very interested in studying your scientific sources regarding your opinion that it is an “extremely rare event”.
Thank you
INTJohn

A common misunderstanding is that all lithium-ion batteries are the same. There are different chemistries available that provide various advantages and disadvantages. Lithium Iron Phosphate (LiFePO4 ) batteries cannot be made in the small sizes required for most consumer electronics, however, when it comes to safety, LiFePO4 technology is by far the safest chemistry available.

In addition, here's a video that demonstrates what happens to different types of lithium batteries when overcharged, short-circuited, stabbed through with a metal pick, or exposed to extreme heat. Normally, a LiFePo4 battery will not catch on fire, but does emit flammable gasses as it self destructs. So if there's a spark to ignite the gas, then you get a fire. But such problems are extremely rare.

CosmickGold said:

A common misunderstanding is that all lithium-ion batteries are the same. There are different chemistries available that provide various advantages and disadvantages. Lithium Iron Phosphate (LiFePO4 ) batteries cannot be made in the small sizes required for most consumer electronics, however, when it comes to safety, LiFePO4 technology is by far the safest chemistry available.

In addition, here's a video that demonstrates what happens to different types of lithium batteries when overcharged, short-circuited, stabbed through with a metal pick, or exposed to extreme heat. Normally, a LiFePo4 battery will not catch on fire, but does emit flammable gasses as it self destructs. So if there's a spark to ignite the gas, then you get a fire. But such problems are extremely rare.

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I get that thermal runaway is “extremely rare”( I presume that or they wouldn’t be allowed on the consumer market) and that relative to other lithium ion batteries lifepo4 are the safest and I also understand that apparently what makes these batteries having a consumer acceptable safety use factor is primarily because of externally applied apparatus like charge controllers etc.

I’m looking for some kind of scientific data that is reliable lab data regarding these opinions to support “extremely rare”. What is the standard? These li battery manufacturers have some hard data someplace or is it all Top Secret?

I.E; Murder is “extremely rare” as well but there is public data to support that it occurs in the US approximately 15000 times per year in a country having a population of approximately 330 million. Someone else might not think this is rare.
“Extremely rare” is extremely subjective.

I’m just asking for sources from a reputable lab like say UL. if you peeps can’t produce any then stop your undefined opinion of what ever “extremely rare” is…… sayin

Thank you
INTJohn

I been using lithium for the past 4 years, I only had 1 fire, but that occurred when I shorted out a lifepo4 26650 cell. As long as you don't mistreat them they are safe. Even after the fire I still use the same 26650 lifepo4 cells, I'm just more careful in handling them.
Due to reading how lifepo4 cells were safer was the reason I wanted to move from the 18650 li-ion to the lifepo4, but after my fire, I don't consider any chemistry safer than the other. When the lifepo4 cell caught on fire, it went up like a blowtorch, very violent and not easy to put out.
I have a 220ah lifepo4 battery bank, and also a 312ah li-ion battery bank. I never had any problems with the li-ion, pound for pound they are lighter and provide more AH's in the same amount of space.
All the fires I been reading about are from e-bikes and scooters which see a more violent day to day use.

I would like to think a manufacturer would consider these factors before putting their products on the market. I think your question needs to be for a specific battery especially since many have built in safety measures (battery management systems) that prevent many of these type problems from occurring. Charging when in the desert heat above 116 degrees and cold in the mountains below 32 degrees seems could cause problems beyond thermal runaway as in damaging the capabilities and number of charge cycles of a very expensive battery if not prevented by BMS. There are however different BMS options as well. One reason I haven’t been able to convince myself to switch totally to lithium ion is because of limited use/charging in temperature extremes. There are days when I worry about charging tool and electric bike batteries and having no good way to monitor possible damage to performance. I just follow manufacturers recommendations and hope they are correct. There are some concerns with Tesla’s batteries fire events even one I believe that reignited several times. Sort of interesting that I believe the Ford Pinto with it’s unsafe gasoline tank had few fatalities than Tesla’s with battery fires and was taken off the road but Tesla continues to be sold.

INTJohn said:

So, I’m very interested in studying your scientific sources regarding your opinion that it is an “extremely rare event”.
Thank you
INTJohn

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... and I yours. You seem to cast FUD at this issue... (fear, uncertainty and doubt) seeming to state that there is an issue, and yet even you say you can find no data.

Doing a Google search showed 60 fires in the New York area in the first few months of this year due to lithium batteries but that is all lithium batteries. According to The quoted experts odds were “less than one in a million.” Again that includes billions of cell phone batteries in their calculations. According to Elon Musk Tesla had .01 percent and independent sources estimated around 300 Teslas had burned.

INTJohn said:

For an anology, think of Thermal Runaway as an extremely scaled down version of a "meltdown" in a nuclear reactor - minus the radioactivity. Thermal Runaway, in a nutshell, is when a battery creates sooo much heat so rapidly that said heat is unable to dissipate in the short amount of time it is created leading to an uncontrollable & unstoppable fire that can occur so rapidly as to mimic an explosion. Of course this "explosion"/fire is prolly happening inside your vehicle............

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Vivere pericolosamente, Johny boi...

I remember several years ago when every other week there was a news story about a phone that caught fire in someone's pocket or purse, or on an airliner.

Substandard batteries were the issue. Around that time, the DOT and the airlines were banning certain models of Samsung cellphones from being brought on airliners due to the spontaneous fires. That could have been related to the in-seat chargers in use at the time...that is a guess, but as a result, air freight shipments of consumer lithium batteries is highly restricted now.

I had two of my older cellphones develop swelling in the battery pack, ruining the phone as it pushed the front half and back half apart. They didn't catch on fire but they could have if the conditions had been different.

Then there was the hoverboard fiasco. Hundreds, maybe thousands, of hoverboards were catching fire, some actually exploded. And the lithium batteries catching fire in the Boeing 787s...now THAT was getting serious!

Then the Chevy Bolt EV recall...Bolts were catching fire and GM dealt with it temporarily by asking owners to not park the car in a garage or near any other vehicles!

For a time during the early years of consumer drones as they matured and got larger and larger, some of the manufacturers were beginning to offer 'battery bags'...a fireproof case that you could use to store your fully charged lithium drone battery in case it caught fire in your back seat on the way to the flying field or video shoot.

The trouble with most lithium batteries is that when damaged due to impact or overcharge, they begin to heat up and the chemicals involved contain oxygen, so the spontaneous fire has its own oxygen supply, meaning you cant put out the fire with water.

I would not call the event extremely rare...I would say 'unlikely' in most normal day to day use.

Luckily, I've only had ONE lithium battery catch fire myself, and that was a deliberate event: I drove a nail thru a cheap aftermarket drone battery and sure enough, it caught fire!

Kinda like gasoline stored in a gas can.....if one takes precautions, uses common sense, and has at least a normal amount of good luck, most people will never have a problem.

I finally found something reasonably reliable as it pertains to Tesla lithium ion batteries on this site:
https://www.wattalps.com/thermal-runaway-propagation-and-mitigation/Their data concludes that about 1 in 10,000 Tesla batteries will suffer an internal short:
From the above link:
“According to the literature, the probability of occurrence of an internal short-circuit for a 18650 cell is of 0,1 ppm (source : “Thermal Runaway Mechanism of Lithium Ion Battery for Electric Vehicles: A Review” X. Feng, et al Tsinghua University – Beijing). This event will therefore occur more often for big batteries and for products made in big quantities. As example, it is estimated that one Tesla battery every 10,000 will undergo an internal short circuit linked to an error in the manufacturing process.”

I also found a UL lab experimental data post provided for manufacturers information which I’ll need to go back & locate.

These “tests” however do not apply apparently to any safety apparatus that accompany battery supporting safe function:
I.e; bms, charge control, cooling fans etc designed to maintain a safe lithium ion battery temperature function. So this now leads me down a trail to the reliability of these items. As if one or more of those might fail it could lead to a catastrophic battery failure.

Fun & fascinating stuff.
I love physics……
INTJohn

INTJohn said:

Of course this "explosion"/fire is prolly happening inside your vehicle............

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Almost no one runs non-LFP lithium as van house banks. The ones that do have typically tinkerers who DIYed their own from used postconsumer cells or bought suitcases from alibaba and are aware of the trade-offs.

It is not entirely clear to me what the purpose of this thread is, other than "chemistries you are not using as house banks might be dangerous!"

Awesome. Purpose of the thread is to discuss ( insert thread title) and then I closed with DISCUSS…….

It’s a conversational topic for anyone interested in discussing said topic - something other than
why are mice in my van
Or
How do I clean leaves & dust off my solar panels.
Or
What’s the best plastic bottle to pee in.

I think it’s interesting too that power station companies like to market their lithium batteries as having a number of lifecycles that far exceeds the warranty they are willing to put on what they are selling. Makes me wonder about safety. Sounds Almost like bait & switch…..
Sayin
INTJohn

frater secessus said:

. . . . It is not entirely clear to me what the purpose of this thread is . . . .

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For me -- and I assume for everyone else too -- this thread's primary purpose is to help people understand how NOT to destroy their home-on-wheels with a battery fire, explaining what the causes of such fires are and how to avoid them.

I've tried to help by adding things I've learned.

Another battery topic I might get to the next Saturday night I’m watching a boring football game is
How to make batteries using human urine:
https://newatlas.com/aluminum-batte... at the University of,such as wind and solar.But lets save this topic for next weekend.
Thanx……INTJohn

INTJohn said:

Another battery topic I might get to the next Saturday night I’m watching a boring football game is
How to make batteries using human urine:
https://newatlas.com/aluminum-batte... at the University of,such as wind and solar.But lets save this topic for next weekend.
Thanx……INTJohn

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I am looking this up right now. There are YouTube videos. LOL An alternate use for all of that pee everyone throws away. Or we could go back to using urine for tanning leather.

frater secessus said:

It is not entirely clear to me what the purpose of this thread is, other than "chemistries you are not using as house banks might be dangerous!"

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lol...

Yep, that is true the LiFePo4 we use in RVs are certainly a LOT safer than the lithium batteries I was referring to above....you know...the cheap ones they put in $500 phones and $50,000 EVs!

I don't have anything to add that hasn't already been said. However, I worked in a Telecom/Data Center maintaining a string of 48 batteries tied together. Each battery was 2 volts and two strings of negative 48 volts. Charged 24 x 7 at 52-54 volts. I entered the battery room and found my rectifiers all charging at a higher amperage then usual. I put a temp gun on the batteries and noticed they were much hotter then normal. I called our power plant engineer and he verified we were in the beginning stages of thermal runaway. Very dangerous with over 1000 amps of -48v DC current. We backed off the charging and lowered our HVAC units to keep the room cooler. Shut off any unnecessary draw that could be removed or lowered. The batteries (gel type) were into 10 years of a 15 year lifespan. It was my experience that the batteries typically never made it much beyond 10 years. Our other office had the same problem the year before which resulted in losing the plant and an injury.

Deleted. I took something out of context