While electric vehicles (EVs) are generally less likely to catch fire than their internal combustion counterparts, it does still happen, and firefighters need to be ready. Accordingly, the UL Research Institute is working with reverse engineering experts Munro & Associates to characterize EV fires and find the best way to fight them.
There is currently some debate in the firefighting community over whether it’s better to try to put an EV battery fire out with water or to just let it burn. Research like this means the decision doesn’t have to fall on only anecdotal evidence. Anyone who’s worked in a lab will recognize the mix of exceedingly expensive equipment next to the borderline sketchy rigged up hacks on display, in this case the super nice thermal imagers and a “turkey burner on steroids.” The video goes through some discussion of the previous results with a Chevy Bolt, Hyundai Kona, Ford Mustang Mach E, and then we get to see them light up a Tesla Model 3. This is definitely one you shouldn’t try at home!
While the massive battery banks in modern EVs can pose unique challenges in the event of an accident, that doesn’t mean they can’t be repurposed to backup your own home.
At the moment they’re less likely to ignite, give it another 10-20 years of aging wiring, electronics, batteries and shade tree mechanics then grab the marshmallows.
that’s true of any vehicle, my dad had a 1998 Dodge Dakota in like 2010 or so it busted a fuel line and burned to the ground in the middle of his (long thank goodness) driveway
Chances are that the balance will tip the other way as fossil fueled cars vanish or become extremely well maintained collector items and the ageing fleet of vehicles becomes majority EV with all the bodges and shoddy repairs, for example the aftermarket battery repair services I’ve seen right now terrify me, just wait until Jimbob is doing his own duct tape and visegrip job.
I don’t know if it’s true, but I was told that most “supercars” end their lives in flames. They don’t get driven much and therefore owners neglect to change our rubber hoses, which leak fuel and bring an end to the vehicle.
Fossil fuel … Vanish? Not anytime soon around here. They may be one or two EPs running around town. More of a novelty than anything…. Look at me types…
Fire is no fun whatever fuels it. Doing R/C I understand the danger just in those little batteries. Especially when carrying a charge and you ‘damage’ them.
RC batteries tend to be a much more volatile blend of battery chemical and made as light weight as possible – so no safety features, armoured cases, cooling etc to help control the burn rate. While I agree an unwanted fire is no fun no matter the fuel comparing the EV batteries to RC doesn’t really work that well – they are just not really the same thing at all. And a good thing too as RC style batteries at an EV scale is the stuff of nightmares…
(as a general rule at least – I’m sure somebody out there does RC with the heavier and safer batteries, with an armoured box that makes the typical EV battery look as bad as the typical RC battery generally looks to the EV.)
“Reverse engineering experts” when the EV makers should be working with them.
In the video, the emphasis is put on the independent validation. You hear several anecdotes, but these are not independently verified. An EV maker may know their own models very well, but Munro worked on many different vehicles. Their reports are used to develop methods to repair battery packs rather than simply replacing them. This in itself isn’t in the best interest of the manufacturers, who prefer you just to trust them. Munro’s knowledge is independent and of great value, and highly appreciated by UL in this case.
“characterize EV fires and find the best way to fight them.”
Using a large lithium-ion battery safely is like trying to keep a pyramid balanced on its point. So long as you do that, they work great. The issue is what happens when, either through internal failure or external factors, the pyramid topples off its point.
The best way to prevent an EV fire is to NOT store 75 KWH of electrical energy in a high-density package that is not only prone to assault by temperature extremes, water ingress, and mechanical shock/damage, but is intrinsically unstable to boot. “How can you have an EV and not do that?” you might ask. Well, you just answered your own question.
I’m a big fan of electric drive trains. Somebody call me when a production-ready electric, with a fuel tank and fuel cells, becomes available and affordable (without government subsidies).
fuel cells in vehicles either suck by their nature or make little sense…hydrocarbons are better utilized with existing heat engines. Green hydrogen performs worse then batteries because of conversion losses and is a pain in the ass to store and transport. Also knowing you’re literally sitting atop a tank with an operating pressure of up to 80MPa certainly wouldn’t give me a warm fuzzy feeling…
Agreed. I’m not a fan of hydrogen fuel cells for commuter-car use. I was thinking more along the lines of a perfected ethanol or methanol fuel cell.
hydrocarbon…
oh and the study is about what to do with an EV that’s already on fire, not how to keep them from igniting :P
A way to have an EV and not do that would just be to use a safer battery chemistry. There are more dangerous chemistries too such as li-po that aren’t used in production EVs for the same reason (although they’re commonly used in consumer electronics). But the fire stats indicate that li-ion and lifepo are safe enough. Some new safer chemistries such as solid-state lithium and dual-carbon should hit the market soon. Nimh and lead-acid are safe enough too, although their energy density is too low to make a practical EV.
I haven’t watched the video but I’ve long thought that a good way to fight EV fires would be with the addition of a flatbed crane truck with a junkyard-style claw end that also carries one or more lightweight foldable dumpsters. If one of these arrives on the scene of an EV fire, it can deploy the dumpster and let a fire truck start filling it, and then it uses the claw to pick up the flaming car and drop it in the dumpster. The immersion will stop or at least safely contain the fire, and the truck can then lift the whole dumpster onto the flatbed, and the car can be left immersed until enough time has passed that the battery energy would’ve been dissipated as heat.
On a related note I’ve also thought that a battery ejection system would be a good way to mitigate the safety problems of a li-po powered EV. If springs or pneumatic pistons could push the pack clear of the car through the side or rear, not only would the rest of the car be saved but any people inside would automatically be clear of the fire as well. This would require a battery that’s not integrated into the chassis so tightly which should be more practical with a better energy density.
“battery ejection system”…light a fire, receive a $20k battery…nope, can’t see that being abused :D
Interesting idea, ejecting the battery. Just to be “that guy” for a second, if the battery pack ejects the battery far enough away to save the vehicle it came from, what might it hit as it blindly scoots away? I guess we could get one EV fire with two batteries. That’d make for some excitement.
Now I’m curious: Would the catastrophic loss of a battery pack (only) be enough for an insurance company to declare a vehicle a total loss?
My thought was to have it only eject the battery with enough force to give about a car-length of space (on thin teflon sliders probably, this would also limit how far it could slide down a hill) to minimize the chance of any “secondary damage” from ejection.
There’s a very real possibility that the total loss of the battery pack could be enough to declare the car a total loss on insurance, but there are other single assemblies that can do that already – a wrecked chassis or engine on most cars will be enough to total it even when brand new. And on a typical car with a unibody/monocoque hybrid chassis, a fairly mild hit to the rear can be enough.
Imagine the local news story about a cascading event in a parking deck.
I was jokingly thinking about that, and also about the scenario where the typical car had two battery packs (say, for space management?) and ejected them in opposite directions. A very large parking lot could “go critical”. (not really, but it’s an amusing thought)
You do realise that fuel cells and fuel tanks are just as problematic if you don’t treat them right – the whole point is to move a vehicle a long way, which means storing lots of energy. Doesn’t matter how you store it there will be some danger involved with an unplanned release of than energy… In the case of deliberately combustible by design fuels that is one heck of an incendiary bomb that can easily make the EV battery look like nothing – likely vastly more potential energy in a very small dense package vs a large EV battery full of stuff much of which isn’t even easy fuel for the fire…
Design, build and then maintain a Lithium pack right it is just as safe if not safer than than liquid fuels as the fire if it ever happens can’t be carried by the flowing fuel leak over vast areas trivially – its one focused spot of somewhat annoying to properly and permanently extinguish fire vs the potential for a fire that spreads really darn easy… The only thing that makes a EV fire such a big news item now is because it is an EV and so many folks have vested interest in highlighting every time one of those ‘new’ contraptions burns, but just flat out won’t mention all the other burning cars at all!
So yes as research like this rather shows there is a need to find best practices for when shit happens for this newer breed of somewhat dangerous power source. But don’t get carried away or pretend all the other sources are actually safe, they are just a danger folks have gotten so used to it isn’t even worth getting excited about even when it is happening practically on your doorstep, as for the last few hundred years those fires have happened and been dealt with…
Living in a big city for the last umpteen years, I’ve seen plenty of carbecues. They burn like mad, I’m sure it must happen occasionally, but I haven’t (personally) seen one explode. Maybe we’re onto something practical with this liquid-at-room-temperature hydrocarbon stuff.
I once sew a pickup drive past my house leaving an intermittent trail of burning gasoline. I often wonder what happened when he stopped. I like to imagine that someone told him what was happening and he was just calmly driving around and around until he ran out of gas…or found a pond to drive into.
I would doubt many will explode, but it certainly is not impossible. Most likely the actual explosion when it happens anyway will be underwhelming – just be tossing the fuel filler cap or some other weaker point that acts as a pressure release before the whole thing really goes. But pretty real explosions have happened from time to time, but really for an incendiary device the explosion element is usually small as it is just to spread the burning stuff anyway, and hot fuels flow so well that you don’t need added propulsion.
The difference with fuel fires is that we already have effective methods of putting the fire out.
Also, ICE cars usually don’t reignite hours or days after being extinguished.
Everything burns, yes. That doesn’t preclude the fact that some things burn more violently, or uncontrollably than others.
The fact that EV fires have been a recurring topic of conversation (actual technical conversations, not the ramblings of political zealots on the internet) should hint that there is some appreciable nuance you are missing here.
A fuel tank is not a bomb. Despite what you see in action movies and GTA, a puncture to a fuel tank does not detonate your vehicle. Petrochemicals will only burn in the presence of an oxidizer, which is in short supply when a vehicle is engulfed in flames.
Lithium Polymer batteries also don’t ‘explode’, but they are self-oxidizing. This means a lithium fire will burn much more violently and rapidly. It also means that water will not necessarily extinguish a lithium fire, as it doesn’t need an external oxygen supply to burn.
The concept of a fuel being ‘deliberately’ combustible is completely inconsequential. Whether it’s a store of chemical energy, or electrical energy is irrelevant, what matters in practice is how the energy is released, and how it’s release can be stopped or mitigated.
It really is not as for example say your power source was compressed air – then actually getting a fire is basically impossible, which is why compressed air locomotives exist(ed?) – even into the age of electric locomotion. As when you have potentially explosive gases or actual explosives by design the compressed air ‘steam’ locomotive would be used to move stuff around – no sparks from brushes, no heat to speak of, even a tank rupture (which is almost impossible anyway) isn’t very likely to find something to throw a spark with. So no blowing up your munitions factory (etc) moving the stuff around.
Usually but really not always true – but I did say INCENDIARY anyway – as in the sort of bomb that generally doesn’t have much if any bang to distribute the really nasty stuff that burns anyway!
Really the only thing that makes EV a bit different to an ICE car is like a peat fire and no doubt more than a few other fires you can’t just put out the flames you can see with water, cool everything down a bit and walk away… So yeah new best practices do want to be developed, but it still really isn’t a BIG deal.
Heck that petrol car unattended can easily burn down the whole parking structure as the fuel flows and will ignite other cars releasing their fuel etc. The EV burning on the other hand rarely manages to ignite anything else – inferno car that does nothing but maybe blister the paint of the car parked right next to it!. So from the point of view of a fire without rapid response for some reason…
Neither are really safe, but equally neither is really dangerous enough to make the giant fuss over that EV and only EV currently get – you treat ’em properly and react promptly and neither poses any great threat, don’t and you and perhaps your neighbours are potentially earning a trip to the morgue.
Compressed air isn’t fuel. That’s like saying a rock hoisted in the air is fuel. There is stored energy, but a store of energy is not necessarily fuel.
The rest of your response is just dangerous rationalization.
@Jared I did not say compressed air was a fuel – but it is a power source in exactly the same way as Petrol, Diesel, coal, batteries, fuel cells, I guess a flywheel and probably more than a few even crazier options could be for your vehicle. In fact my whole point was that it is not – When you are concerned about fire to the exclusion of all else you shouldn’t select a DELIBERATELY COMBUSTIBLE FUEL as that energy source – as that means transporting around and having to contain something that by design MUST burn readily, and in use you are actively burning – from a fire point of view that is just dumb if you have any other option at all!
Which makes it actually a bad idea compared to even the most flammable batteries, which don’t tend to get used in anything larger than laptops/phone and RC type small devices – as with just a tiny bit of care even those packs don’t burn or even get particularly hot in use to be able to ignite anything else in normal operation. Then even if they do burn while spectacular its very very localised and will tend to stay confined to the failed wreck as absolutely nothing in its construction is designed to burn or flow easily so you can pump it to the engine! So as long as your crappy Chinesium grade battery pack or RC battery isn’t sat on a bed of reasonably flammable stuff it can ignite…
Also you have not got to build a whole industry to refine and ship stuff that burns easily to pumps for everyone’s mobile consumption platforms that must all then carry around something that absolutely must burn rather readily. And as these days all those fuels tend to be relatively volatile liquids and occasionally gas – so spills and leaks leave behind something quite easy to ignite that spreads over an area easily and quickly… Sure it is technically possible for electricity transmission to cause a fire, but by design that should not happen and the thing burning is going to be some extra dried out tree next to the power line.
That’s why metal-air batteries would be the holy grail of electric cars.
Too bad nobody has managed to make one that works well.
Nonsense, I could just as easily say gasoline is trying to evaporate and catch fire and that we’re deliberately pumping it into a place to do just that and expecting it to stay contained. Or that the air in the tires is just trying to explode out and it’s mad to expect it to stay inside while it gets worn and pounded on by all sorts of surfaces and the weight of a car for years on end. Guess what, we can actually build things on logic and reasons and see them work or not.
Obviously the best way is with fire!
I live in a rural environment that borders onto protected areas and therefore I am very wary of anything with a failure mode that is so toxic to the environment. There is also no way we could expect a specialist fire crew to attend a lithium fire either.
Integral fire suppression. Other power plants in the transport industries have this feature(trains, smaller ships, aircraft, some semi trucks).
This could be something built into the pack or a means of carrying the suppressant to the pack. The problem with these fires is getting the flame retardant, thermal coolant, de-oxidant, or whatever is used to suppress the fire, to the source of the heat which is often buried in the body and otherwise inaccessible directly.
Don’t make ICE vehicles do that (outside of some race series anyway), probably for the very good reason it is lots of added mass for something you should never that – a solution that doesn’t scale down to the small stuff so well.
Also is yet another thing to service you know lots of folks won’t bother with – so better to make the fire suppression a distributed solution where one mobile system can when required dash off to put out a fire in a wider area – if everyone was supposed to have self extinguishing entirely ‘safe’ cars in a handful of years when all the maintenance hasn’t been done you have lots of car BBQ and a fire service far too reduced in size to possibly deal with them all.
Splashing water against the outside panels isn’t going to do much to extinguish a car fire.
A while ago I saw a video where 3 or 4 guys pulled a big fire blanket over a car. As you would expect that seemed to work instantly, but it was a short video and I don’t know what happened afterward. This also has interesting opportunities for additions, such as sucking out poisonous fumes and then filtering them to limit environmental damage.
The only reason they are “less likely” to ignite is because they make up a tiny percentage of the vehicles involved in collisions.
The difference between a rechargeable vehicle (aka IED on wheels as I like to call them) and a hydrocarbon fueled vehicle?
1) In the rechargeable vehicle you likely won’t be able to escape the passenger compartment before the heat and toxic fumes kill you. On the hydrocarbon vehicle you’ll have plenty of time and if it’s an engine fire you can probably avoid getting out of the cabin until the windhshield starts melting (nice benefit if it’s the winter season). On the bright side, there will be nothing left but ashes to bury in the rechargeable vehicle, so the funeral will be cheap for owners of those vehicles.
2) Forthe rechargeable vehicle fire, you don’t really need to worry about putting it out, because you aren’t going to put it out, so the fire department will be able to conserve water. Yay!
3) Buyer benefit! The rechargeable vehicle will always be a total loss in a fire, as opposed to the hydrocarbon vehicles which are regularly salvaged after fires, so no need to do a carfax on the rechargeable vehicle to see if it has burned before. At least $33 saved for rechargeable car purchasers! Who cares if they cost 2-10x the price of a hydrocarbon fueled vehicle, that is thirty three bucks SAVED!
Etc…. etc…. etc… I see maybe 3 rechargeable cars per week in my area, I always wonder who is actually driving them… Must be in the big cities or something. Drive one where I live and you’d be stranded half the week (and all winter lmao)
I’m sure people die in Tesla fires, but that’s kind of a Tesla issue.
Batteries take a minute to catch and the car is screaming at you the entire time to stop and get out. Half the EV fires I have seen had the passenger cell undamaged.
Meanwhile gas fires happen /real quick/ because gas leaks out, and gas forms flammable atmospheres, and gas goes off all at once. You have, I presume, seen fires in competition cars? Seen the fire-retardent suits the drivers wear because things tend to go wrong immediately?
Furthermore, do you really think the NFPA and other researchers don’t normalize the rate of fires by number of vehicles on the road? That’s freshman statistics for non-mathematicians, if not high-school stats.
As for people who drive them – hi! EV motorcycle, EV sedan. Torque for days! Actually thinking I’ll run the math on cost per mile between the sedan and my Tacoma, they’re at about the same mileage. Let me tellya, putting 100 miles of range on the car for like $7 is pretty sweet. Took it halfway across CA for a trip to Yosemite, and it compared well to my fiancee’s old Prius in trip cost – except this sedan is much mote ‘American’ (bigger and faster).
I have no idea where you get your information. Every EV fire I have seen in my area has resulted in fatality of at least the driver and the vehicle was burnt to a literal crisp. Are you talking about hybrids? They have small battery packs. When an EV aka rechargeable car pack goes, it burns for hours and there is nothing left.
As far as EV motorcycles/bikes/etc, just watch the video of the guy who carried his electric bicycle battery into an elevator with him… I will never let anything like that near my house.
“EV” aka rechargeable vehicle is just an IED on wheels. It’s that simple. Liquid fuel fires are highly predictable and easily extinguishable.
Also, no need to run the math, it was revealed a year or so ago that the claimed “economy” numbers for the electric vehicles was being multiplied by some ridiculous factor (something like 4.66?) and when you do real math for the rechargeable electric vehicle, the rechargeable vehicle is only marginally more fuel efficient than its modern liquid fuel counterparts, but costs many times more than its counterparts. If you include maintenance costs and longevity, the liquid fuel vehicle wins by far. Rechargeable cars are for rich people who have money to burn. The cheapest Tesla costs more than 5x the maximum amount I’ve ever spent on a single car. It is crazy to me to think that people actually have so much money that they are willing to spend that much on a car that can’t even drive 200 miles without needing to stop and charge for an extended period of time…
Complete nonsense. We know how much energy is in fuel; if you give an electric motor the same amount of energy with a battery, it will turn almost all of it into motion instead of wasting it like an engine. So yes, there’s a large factor difference in mpg and mpg-e in the same car, and that’s because that difference actually exists in the underlying tech. That’s why we can use batteries already even though they store only as much energy as a few gallons of gas – we can get much farther on that energy than we would on gas. And you’ll not need to maintain the motor at all – nor the battery until a few hundred thousand miles and a decent number of years, so long as neither you nor the manufacturer has abused it.
The built-in cremation is something that hadn’t occurred to me. Not sure if it would help inform your cost-analysis, but I’d point out that most often in the case of cremations the remains are scattered rather than buried.
Around 1 in 20 cars on the road in the US are EVs, maybe they just have better drivers?
That’s definitely not it. The thing is, there are no “US roads.” Downtown Portland, OR seems close to 50% EVs, Twin Falls, ID is less than 1%. I don’t think you need to look up statistics to know which has more accidents per capita
Spoken like someone who’s never seen how a regular fire progresses.
I had a Mitsubishi iMIEV for a while, and the guide for auto wreckers made interesting reading. The recommended procedure for dealing with the battery was to pull the rubber plugs that seal the pack (reassuringly located under the driver seat!) and immerse the car in several feet of water.
Maybe all EV battery packs should be equipped with an externally accessible firehose connector to make it easier to flood them (you know, in case you don’t have a front-end loader handy).
Renault started to license for free their patents about such firehose connector so all car makers can use it. They call it Fireman Access.
Not sure if flooding a pack that hasn’t started to run away so directly would really be a good thing where so much lithium is involved. But as many of these vehicle do now have liquid cooling to give faster charge times without destroying the battery that might be an idea to prevent any chance of thermal runaway by rapidly force cooling it with externally supplied high pressure for high flow speed water.
There’s only a few percent lithium by mass, you know. Might not always suggest mixing electricity and water, but if one burns it’s probably stuff like the flammable liquid electrolytes and stuff that are doing most of the burning.
Since cooling access is so difficult to achieve but critical i wonder if they could put a connection point on the car that fire fighters could connect too once the cab is under control to allow an easy way to flood the packs
This deserves much more discussion. I has a recycled lipo pack start burning in my home / lab and I quickly wrapped it in kapton tape, placed it in a Swiss ammo can (high strength plastic with metal tapped bolts and air seal. Then flooded it with cold water and sealed it up outside. Thermal management seems to me the most successful protocol if it has not become fully involved. Cut off the air, the kapton tape did a good job as it stopped the reaction for the moment. The battery was still warm. Then upon cooling it in an air deprived environment. It did a good job but it has just started smoking and did create some charing on the wooden floor.
I got sooo lucky it happened while I was home and now I have removed all the lipo packa (good or marginal) and have stuck with the normal lithium ion cells that have built in fuses.
The packs inside new devices and smaller devices (M5 Stack, Cardpewter, HackRF One the new Maham edition) and such…
But, this method worked for me. There are several YouTube videos about the “lipo packs” that are supposed to contain work in some cases but there are no standards. Storing many together is a bad idea. I would wrap any marginal packs in kapton tape and seal them off to the outside of air and any metal contact points that could short upon contact with any metal. I think this or my stepping on accidentally as I was working with it before sleep. When I woke up in the morning. I went and did morning things. Then laid back down and saw the smoke. I am assuming that the “crystals” that develop over time perforated the interior membrane.
I would be very careful with lipo packs either new, semi-used, or marginal and any bloated pack should be appropriately disposed of and in my particular area there’s a special drop off for those particular items and you’re not supposed to put them in the normal battery recycling.
I have wrapped all of my existing versions and taking them for recycling. For hobby is use I would stick to the battery cells.
The lipo battery packs are just two potentially volatile especially in a home environment.
If you have a shop and you can store them in a fireproof container with a very heavy duty fire rating and take measures to keep them from contacting other metal etc and it would survive a very serious high temperature blaze without causing any damage to your shop or to your house that would be appropriate.
Over priced, dangerous, not sustainable, mining the materials needed will not reduce carbon foot print, , 10 seconds to vacate from first sign of storage tub expansion, ejects toxic flammable gas then 10 ft flame or explosion, lithium burns and creates own oxygen , burns at very high temperture, water possible shorting, Or shock, charging between 12deg to max 40 deg limited battery life and time takes to charge is waste of time compared to refueling stop. Increase life and property insurance, once damaged voc would not make sense to repair so disposal required, toxic landfill and hard to recycle due to high voltage . Current building codes are not able to protect infrastructure. If fire in garage, your house is gone to due to voc contamination. Excess water required or cover in sand, to put fire out. Fire fighters refusing to enter fire zones due to toxic fumes as gear not yet fully tested. Technology needs to change. Travel distance needs to increase and charging and electrical infrastructure is not there yet, not efficient use of resources or money, or time. I will stick to my ice vehicle . I am glad ul is undertaking the testing, good job, the more information the better to help save life and resources.
Regards
IC.
I was thinking, what about a charging box for small batteries that has an automatic fire extinguisher. Like halon extinguishers, but those are problematic… there must be some other gas or chemical that would be safer, could be automatically triggered if the temperature goes up too much, and maybe could actually put out a lithium battery fire? Yeah there’s that whole problem that the battery supplies its own oxidizer though, so maybe it’s hard to find a gas that could counteract that.
Maybe the day will come that some sort of automatic fire exinguisher will be considered a “must” in your home garage too. I live in a building now in which the basement is a garage, and EVs are very popular here (most of those EVs are charging there too), so maybe it’s just a matter of time until one of them starts a fire. Not that so many gas tanks in one place was any better.