Although battery fires in electric cars and two-wheeled vehicles are not a common phenomenon, they are notoriously hard to put out, requiring special training and equipment by firefighters. Although the full scope of the issue is part of a contentious debate, [Aarian Marshall] over at Wired recently wrote an article about how the electric car industry has a plan to make a purportedly minor issue even less of an issue. Here the questions seem to be mostly about what the true statistics are for battery fires and what can be done about the primary issue with batteries: thermal runaway.
While the Wired article references a study by a car insurance company about the incidence of car fires by fuel type (gas, hybrid, electric), its cited sources are dubious as the NTSB nor NHTSA collect statistics on these fires. The NFPA does, but this only gets you up to 2018, and they note that the data gathering here is spotty. Better data is found from European sources, which makes clear that battery electric vehicles (BEVs) catch fire less often than gasoline cars at 25 per 100,000 cars sold vs 1529/100k for ICE cars, but when BEVs do burn it’s most often (60%) from thermal runaway, which can be due to factors like a short circuit in a cell, overcharging and high ambient temperatures (including from arson or after-effects of a car crash).
As for the claimed ways to make battery-powered vehicles safer, the Wired article mentions the shift to more stable lithium-ion chemistries like lithium-ion phosphate (LiFePO4, or LFP for short), experimenting with solid-state batteries and easier ways to extinguish a fire and disconnect the BEV’s battery, along with firefighter training. Meanwhile the European Union will require a ‘battery passport’ starting in 2027 which tracks the origin, manufacturing and testing of batteries.
Of the risks with batteries, thermal runaway is probably the least predictable, with a review article by [Mahn-Kien Tran] and colleagues in Processes from 2022 covering our current understanding here, including ways to model and predict the occurrence of thermal runaway to increase safety while e.g. charging a battery. As internal shorts due to wear and/or manufacturing defects can be hard to predict, it is essential to detect thermal runaway before it has a chance to get out of hand.
Beyond electric cars, electric bikes are far more notorious for catching on fire, with these devices in New York City having gained the reputation of burning down apartment buildings, generally while charging. As MIT Technology Review reports, a solution here may have been found in battery swapping stations that are equipped with sensors and fire extinguishing systems, so that delivery drivers and other e-bike users do not have to charge batteries at their apartments while praying that they don’t wake up to thick smoke and a screaming fire alarm.
As battery-powered vehicles and devices become more and more common, it’s clear that even if the risk of fire from these vehicles is small compared to their gasoline-powered brethren, those generally do not catch on fire while parked in one’s garage or hallway. Finding ways to mitigate this risk is therefore more than welcome.
the difference between cars and electric bikes is that cars have to pass safety regulations to be sold, where electric bikes are made by anyone, to any random design, and may or may not even been tested – and might have the cheapest charging circuit and battery they could find.. So yes, they catch fire a lot…
Do you really trust those chinisium batteries that much? Yeah, passing regulations is one thing, keeping quality solid is another.
Where does one get a NOT chineseium battery quickly and cheaply? I have battleborne just down the street, but they don’t make small portables
this is an example of where social phenomena come into a technical problem as well. electric cars are relatively less likely to be stolen / more likely to be recovered or compensated, relatively more likely to be a status symbol, and relatively more of a known quantity before purchase. so people are likely to spend a lot of money on an electric car and view it as an investment.
on the other hand, electric bikes are relatively common to steal, relatively more likely to be simple utilitarian transport for relatively impoverished people, and relatively unknown. so people buy them on a lark (uncertain if it’ll be useful at all), or they buy them just to fill a need. they are much more price-conscious. and on top of that, a lot of brands are making “me too” electric bikes for fashion / PR reasons, without really advancing the state of the art of engineering them. as a result, cheapest / crappiest remains at the forefront of the electric bike market.
just a weird case where something totally non-technical like “police care about a stolen Tesla, do not care about a stolen Tern GSD” comes to have material effects that engineers are then asked to try to solve.
Electric bikes aren’t really that great value in the end. A typical commuter distance on a bicycle is about 5 km, so 10 km round trip. 5 days a week, 52 weeks a year makes it 520 km a year. The lifespan of the bike is about 10 years, so 5200 km total. If the cost of the bike is €1000 then it’s 19 cents a km.
Even with European fuel costs, let’s say €1.8 a liter and 6 liters per 100 km, that makes it 11 cents a km, which is significantly less. For anyone who also needs to own a car to get around further than 5 km from the house, in all weather, trying to save money with an e-bike just doesn’t work. Your daily commute must be more than 20 km to justify the e-bike, but then your commute time becomes longer and you begin to suffer the elements trying to ride all year round.
A regular cheap city bike costs a couple hundred euros, so that’s real value – that can save you money. I calculated that the maximum price I could pay for a bike would be around €800 – and that’s pretty much the bottom range for e-bikes. I don’t see how e-bikes would be a sensible option for the “relatively impoverished” unless it’s really their only mode of personal transport.
Wait, I forgot to multiply by 5 in the first part. That means e-bikes start to make sense past 4-5 km daily commute – depending on how fancy a bike you want to buy.
Mine is just under that limit, so it doesn’t.
You think your getting 10 years out of a cheap e-bike?
Unstolen for 10 years (if it was good)?
Also England. Weather prohibitive 300 days/year. Lunatics driving on wrong side of road. Minimum blood alcohol for driving laws.
No. If you have to keep it outside on a bike rack, it’s 2-3 years max before ice and water breaks in and destroys the battery socket. It’s difficult enough to keep the gear of a regular bike operating under those conditions.
@dude
It really isn’t, until I gave it away I used my bicycle daily for many many years, leaving outside here in England for many many more hours than it was under cover, and it wasn’t new when I got it either… The only thing that was problematic was one of the wire lines IIRC for the rear brake had to be replaced (but it might have been the gear derailleur) , and I don’t think that had anything to do with the weather really. All you have to do is add some oil from time to time, clean off the worst crud build up on occasion etc. Its a few minutes of maintenance you have to do only very rarely – more likely you’ll manage to get a irreparable puncture on our terrible roads than have any weather related issue. And as soon as you have to pull the tyre off you might as well do a more complete repair.
There you may have a point, though most E-bikes I’ve seen the battery socket or charge connector isn’t angled in a way it will pool water even if you tried to make it.
@HaHa
Indeed that is the more likely issue now, cheap or otherwise if it looks vaguely worth stealing and you have to leave it in a relatively unsecured location every day for 10 years at some point yours is going to be the easiest one to steal that is worth the effort..
How many freezing days did you get? Last January I had to pull all the cables out and wash them in isopropanol, and then soak them up in gun oil, because they kept freezing solid and I couldn’t operate the gears or the front brake. That’s why I always buy bikes with coaster brakes, because the rear hub has to be sealed well against water and packed with grease or it’ll break almost instantly, so you always have at least one working brake.
Electronics can be potted to be impervious to water, but for the usual suspects that’s a tall ask. Connectors are a huge issue even for the best of them. I bought new (cheap) front and back lights last year and they’re already destroyed by corrosion, because you have to swap the battery, and the seals to the battery compartment leak. Even if it was USB charging, water tends to get into the connector and climbs up the cable in between the wire and the coating by capillary action, so you can’t leave them outside for long.
You have to keep removing the battery or people will nick it, and wind pushes the rain sideways sometimes, and there’s fog and mist coating every surface up or down. Capillary action takes care of the rest – small gaps, seams, and the space between strands of wire in a cable just like to pull the water in. Then there’s also temperature variations which cause the air inside the electronics to expand and contract, literally sucking the water in through the cabling and the connectors.
Professionally, I’ve designed some devices that have to work outdoors all year round and I can tell you it’s a real uphill battle. Things you’d think are waterproof, that are sold as waterproof, aren’t. Something that’s sold as IP67 sometimes can’t even survive exposure to high humidity, because condensation happens and then the thin film of water gets sucked in.
Dude the UK as a whole generally doesn’t freeze, and when it does its not a very deep or rapid freeze (usually). We don’t tend to get humidity and temperature swings that will really encourage condensation in a big way outside. So as long as you add some oil in all the moving parts from time to time and give it a proper clean once in a while…
I don’t disagree its a potential challenge, as obviously it is, but here in the UK I’d think its the potholes that are the big bike killer, then probably excess road salting that is more likely to kill your bike than directly water related problems..
Dude – what you say about waterproofing..man! can confirm!
it’s a big frustration for me. i ride an acoustic bike so my only battery device is the lights…i used to use expensive lights from blackburn, and they were ‘waterproof’ — they would let water in but not out! after months of sitting indoors unused, i opened them up to do a post mortem, and they were still full of water! so i started making my own lights….i don’t do anything to keep water out…so they get wet, and then they dry out overnight. the other thing i do is i solder the battery connectors so it doesn’t get corrosion exactly at the battery terminal. (i haven’t parked a bike outside for more than a couple hours in decades)
i get 5+ years easy out of such a light, but i rarely get even 6 months out of a blackburn- or cateye-branded light.
i don’t know what the state of the art for e-bikes is in terms of water resistance but i find it very easy to believe the main players screwed it up.
The decision to use an e-bike is often based on factors other than cost.
The time and convenience to travel are important factors.
The decision to use a car also includes more factors than the cost of fuel.
Parking, traffic, insurance, taxes, and maintenance are but to name a few.
Of course, one must also consider both the landscape (hilly or flat?), the
typical destinations, the safety, the likelihood of theft or vandalism, and
the availability of other alternative means of transport as well.
I feel like you’re forgetting about insurance, parking and maintenance costs in this equation. I’m not even confident that will tip the scales in ebikes favor, but it might make the gap a little smaller.
If you already have to have the car anyways, those don’t count because they’re inevitable regardless of whether you also own an e-bike.
Also, if you ride the bike and let the car sit on the parking lot with little use, you’ll get issues and extra maintenance costs with batteries running flat and brakes rusting, and tires going square from static compression. Moving it a few km every day keeps the bearings and seals in better condition.
You amortised the bike but you didn’t amortise the car.
Double the fuel cost for car running costs (tyres, parts etc).
Then a secondhand car starts at $/£/e1000 and reduces by the same rate over 10 years. But add in inspections (£600) insurance (£1500++) road tax (£2500)…..
Just occurred to me you are factoring in only the vehicle cost for one and fuel cost for the other is rather apples and oranges…
So as the car costs usually considerably more than the bicycle, even if its an electric bike, and may end up with no longer lifespan, with undeniably more expensive fuel consumption, and probably a whole heap of extra monthly/yearly costs to be allowed on the roads…
Far as I know nowhere is yet trying to apply road taxes, annual vehicle inspections or mandatory insurance requirements for bicycles. And oh boy do those add up to a great deal round here – you’d probably save a very noticeable amount as the pay by month ‘relatively impoverished’ scrimper just declaring your car off the road in the nicer months of the year to cycle so you don’t have to pay the insurance for that month or two.
Ultimately nobody can say for anybody else what the best choice is, everyone’s lives are in different places. But the price of an e-bike is for most I’d suggest affordable – more likely to manage to get an e-bike than even run a car given to you free if your really really broke, and if you can afford a car you can probably manage to afford an e-bike as well (especially if your using a kit on an old bike) – which makes the comparison likely rather more about direct running costs… And there I’d suggest the e-bike slaughters most cars, especially at the budget end. So if you can only afford to buy an old junker barely able to stay out of the scrap pile legally then your going to spending a small fortune on bodges and parts to keep it alive, and a great deal more of fuel I’d suspect – in this case every mile you can avoid driving thanks to the e-bike so you don’t have to replace any of the worn but not quite MOT failure parts this month is probably a winner…
Police don’t care about a stolen car of any kind unless it has electronic tracking that will lead them right to it. Then maybe, if you call them and tell them ur looking right at it, maybe.
Tell them your carrying and they will be right their to protect the thief.
Their job is filling out a police report for the insurance company. That is all.
That and beating your ass for cardio.
One of our local EV charging stations has been down for nearly a month after an EV caught fire while charging. It’s a real – if (hopefully!) rare one.
Before anyone tries to claim I’m anti-EV, I’m an EV owner. Unfortunately, the station that was taken out has 8 chargers, leaving me with a 3-charger station as my only realistic local option, so it’s pretty inconvenient. At least no one was hurt in the fire – the owners were shopping while their car charged.
Worth pointing out that if there is ever a fire at the petrol station it can take a long time to repair and reopen as well. That ongoing inconvenience to everyone after an accident isn’t unique.
In the case of petrol and diesel right now you probably have more ‘local’ options as its the more established system, so you’d expect more minor inconvenience. But if you don’t you are even more in trouble than the electric car would be, as those can be charged even if its so slow it takes all night with a long extension cord and your normal household electric.
Fast charging stations cost a lot of money to build in the first place vs. regular old tank in the ground and a fuel pump. A single pump is about $20k investment, whereas a fast DC charger can range from $45-100k. That’s the main reason you don’t see them everywhere.
And you wouldn’t be in much of a trouble if you don’t find a service station and you run out of petrol – you just call the AA and they’ll bring you fuel, because you can do that with liquids: carry them in a canister.
A single pump would never be built.
A large cluster of pumps might come out to $20k/pump.
Until the tank leaks.
In the USA, there are former gas stations all over the nation for sale.
You buy them, you bought the cleanup bill, nobody that stupid.
They would, but in those cases the tank is typically above-ground to save on installation cost.
The same thing applies for EV chargers. A single outlet may cost $100k while the grid connection and the field wiring and installation cost will be another $100k so it’s not efficient to have just one.
You can’t call the AA every other day/week for the month or so it takes to replace the one petrol station in a sensible range of you, and you might well need to if you do lots of miles or your vehicle a fuel hog…
Both of which are probably true – as if there is only station in a reasonable range you are in the middle of nowhere relatively speaking, so probably have to go a very long way every time you go anywhere… Though maybe you can talk one of those fuel trucks the like that follow Dakar rally competitor around to park up and play temporary petrol station.
How often do you actually run out of petrol between service stations? When the “student light” comes on, a typical car will still go the distance to the next town. That’s because there’s a sump in the tank designed to always keep the fuel pump under liquid even if the fuel is sloshing and splashing around, for cooling purposes – and that sump contains enough fuel for a reserve. Most people never go that low before refueling, because the meter says empty before you run into it. For a petrol car, it costs nothing to have this couple liters of extra space in the tank.
For an EV, you don’t really have any reserve because you’re already pushing the range it can give you anyways. Every bit of reserve costs thousands of euros. This has some interesting consequences. There’s a tunnel in Norway that traps Nissan Leafs because there’s a long incline at the end of it that requires extra power to climb, which causes the Leaf to fault because the voltage on an almost empty battery sags enough that it reports empty.
Not to mention that EV manufacturers like to lie about the true range of their cars anyways. They always “round” it upwards – and some manufacturers were even caught fixing the algorithm so that it reports more miles when full and then adjust the estimate down once the battery nears empty, so one kWh counts for more miles depending on what the actual state of charge is. You start off thinking you can go the distance with plenty to spare, and end up with ten kilometers remaining when you reach the destination.
The “mileage gap” exists on regular vehicles as well, but that’s more about what numbers are reported to the authorities to calculate CO2 emissions per km – meanwhile the trip computer is more likely to under-estimate how many miles you can go with the remaining fuel.
Dude you do realise you are just agreeing with my point, as I did say in a sensible range of you… If there isn’t another petrol station nearby, then you are out in the middle of nowhere – at which point the few tens of miles an ’empty’ tank might take you won’t matter at all, it just reduces the distance you’ll have to walk…
Which isn’t that impossible when you look at giant nations with sparsely populated areas, like most of the central USA or Russia for instance – long long way to go between towns there at times. Heck a long long way to go just to get to the neighbours place in some of these areas…
The lies and omissions of the claimed range really don’t solve the problem for the ICE either – sure it is more likely to exceed the range the trip computer/fuel tank needle suggests than an EV is. But once you are running on fumes or stray electrons you are screwed and if you come to rely on being able to do 70 miles on an ’empty’ tank you’ll find your equivalent of that tunnel that denies you this time – as always you need to either play conservatively or actually really know your vehicles true capabilities and in the case of EV’s have a good topographical map of the route as going down hill can end up providing a substantial range gain.
On another site, someone posted picture of an EV on fire in a parking lot of a store he was at. Hopefully no one parks these in garages, but keep them out on the street. I use these batteries in model airplanes and know how bad these fires can be (and they are ‘small’ batteries in comparison).
Have you seen a petrol fire?
Flight batteries are engineered to be cheap, high-capacity, and as light as possible, not to be safe. An EV battery has a completely different set of design criteria, and to claim that the risks are comparable is to be wrong or to be disingenuous.
It’s not as bad, but EV batteries and the companies that use them are no saints.
Tesla for instance wanted to use NMC cells for their added robustness, but still uses NCA which is prone to thermal runaway, because it’s got greater energy density and costs less. To combat the fire issues, they encase the cells in heat expanding foam, which is supposed to isolate failing cells, but with a big enough fault it’s not really adequate.
I’d say “that’s capitalism for you”, but it’s also just a reminder that there’s no perfect solution that maximises every desirable trait. You always have to compromise.
That’s not even “capitalism”, but, “easier to say sorry than ask for permission.” Early adopter risks are easily denied: remember how cars used to come without seat belts or folding steering columns and people died, and nobody cared?
In one respect, flight batteries are safer than EV batteries for overload conditions, since they’re designed for minimum internal resistance and massive load currents and specific power. EV batteries are optimized for weight and energy density, which makes them overheat on short circuits where the flight battery would probably cause the external short to explode away rather than exploding itself.
The flight batteries are made of materials that are less chemically stable, burn more readily, and they’re packed in without protective shells for mechanical damage, but they’re made to handle much more abuse electrically.
“Have you seen a petrol fire?” -> How do you think we start camp fires up here??? :D .
Do you use automotive grade cells (Panasonic, Samsung), off-brand cells of the same style, miscellaneous mobile-device pouches, or rc-marketed pouch cells?
Which is still biased information, because of the heavy bias towards new electric vehicles vs. cars of all ages on the roads. With the rapid growth in the market, the vast majority of EVs on the roads are only few years old, and new cars break down less than all cars.
The criticism around 2009-10 when these issues were first getting raised was that EVs could not get the promised range improvements despite battery technology improving rapidly. It was known that larger batteries were a fire hazard waiting to happen, and increasing energy density would make it worse, so the support and isolation structures necessary for preventing and protecting against thermal runaway would eat up the gains in battery energy density. The industry – mostly Tesla, as others were more conservative about the matter – chose to ignore the warnings and put in bigger and denser batteries using chemistries that were prone to fire without adequate shielding to save on mass. The end result was cars that light up in seconds following a crash and trap the passengers before help can arrive, and burn down parking garages and other buildings because they’re so difficult to put out once on fire.
The age of the vehicle is not a huge factor in them catching fire or not, as most vehicle fires for any energy source are because of accidents and inadequate maintenance/repair – which can happen to almost any age of vehicle, or sometimes active design flaws. Also all the studies I’ve read are only ever comparing the EV be it more luxury Tesla’s or town car Leaf’s to the comparable age and usage fossil fuel cars, not all cars ever made.
So while its true that age makes it more likely this particular vehicle is an accident waiting to happen that is about a great deal more than just its age. I’d tentatively suggest its rather more likely because the folks buying and running older cars tend to be too poor to really maintain them properly. You don’t hear or see many of the more classic valuable old cars burning. So I’d suggest with EV that is going to be a self damping feedback loop – too poor to maintain the car as the battery ages means you don’t actually have a useable car that actually goes anywhere – can’t cheaply and jankily bodge them the way you can for most of the more perishable parts of an ICE power train.
Not true. Newer vehicles are driven by a different population of people and are generally in better shape and equipped better for collision avoidance, lane keeping etc., and newer vehicles haven’t yet had the time to run into disrepair.
Think about it: people who can afford EVs are mostly middle class or greater and middle-aged or older, since nobody else can afford to plonk that much money on a new car. Working class people and the more risk-prone young drivers simply don’t buy them.
If you’re in the demographic to buy an EV, you’re not likely to drive it like you stole it – hence the lower accident rates.
You can easily end up with folks that have a nearly new car and then end up say having an expensive divorce for instance – the point being its not the age of the car and it can happen to the new cars. The issue isn’t the age its the lack of repair.
Or to put it another way the absolutely ancient bloke down my road with whichever even older classic he drives now (been a while since I walked down the road in that direction so for all I know he may have reached the point he isn’t fit enough to drive) isn’t going to have a vehicle fire any time soon for lack of maintenance as whichever car has at the moment is probably as good if not better than it came out the factory… A car that is probably double my age if not more, but its in perfect condition, while on the same street mostly populated by students you have cars from this side of the millennium that look they are held together more by hope than anything else…
You can, but this is about statistics over large populations and not special cases.
You’d need to have a lot of divorcees driving beat down EVs to sway the numbers, and you’d need many years to wait for those accidents to happen.
How many of those students are driving EVs or finely maintained historical cars? The reason why they’re driving broken vehicles instead is because they don’t have the money.
The old guy with the perfectly preserved historical car is in the category of people who have the money and the time, so could afford the EV if they chose to. The other people who drive ratty cars don’t, so the EVs end up more with people who care for and about them while the other cars end up with people who neglect them.
Then there’s an entire other thing about what counts as a vehicle fire or what is reported as a vehicle fire.
Recently in the news I read about a van that caught fire on the highway. The catalytic converter was completely corroded, blocked, and exploded, setting fire to the underside of the van. A passerby put it out with a handheld fire extinguisher. Small fires like that happen often, with something like an electrical fault or an oil leak making smoke under the hood – nothing very dramatic happens – but the insurance claim says “vehicle fire”.
Comparing these cases to EV battery fires is a bit apples to oranges.
There I agree, but equally how many fires might there be in an EV that are not battery fires – still plenty of other wires and components that could cook off, the mechanical brakes etc. Unless you have a perfect brakedown of the causes and severity of every vehicle fire all you can easily do is compare the total number of fires.
Also had there not been a passing motorist with an extinguisher that Van probably does become a raging inferno – as any untreated fire around the rather flammable fluids in a vehicle has a good chance to get out of hand into total loss pretty darn quickly.
Again, newer cars, less problems, owned by people who have the money to pay the higher insurance rates and maintain them more diligently to keep the warranty.
The point about the extinguisher was that you could put out the fire with something people have. You could throw sand or snow on a small engine fire and put it out, but if the battery goes, you can do nothing.
Dude the battery has to really really go for it be really hard to deal with – these things are built like tanks, with lots of thermal mass and usually active cooling. Which means stopping or at least postponing the thermal runaway when a single cell or two is busted is just as possible as stopping the ‘small engine fire’.
Once its really got going there is no stopping it easily, which isn’t all that different to a well established ICE fire, just with the added caveat that adding water to lithium has more fun results, so long after the trapped occupants would be dead the fire service has to hang around…
And again you are entirely missing the point – its not got anything to do with the age of the cars! The actually important detail is the quality of maintenance, and while that does correlates somewhat in ICE with the age of the cars it isn’t universal even then. And it isn’t likely to apply nearly as much to EV as the ‘cheap EV’ is the one that isn’t a useable vehicle any more – once the battery which is the biggest and only uniquely different ‘consumable’ component starts to die the poor folks can’t just bodge it with cable ties, bailing wire and garden hose the way they can with the most perishable bits of ICE power train. An EV battery is something you’d need to actually know what you are doing to touch without killing yourself, and dangerously bodged replacements would be rather challenging to pull off in a way that actually works…
The only vehicle fire I’ve ever seen (other than on a racetrack) is a Ford escape <5 years old. Sample size of 1, but ¯_(ツ)_/¯
In the past 3 years I’ve seen 2 petrol based vehicle fires.
One I arrived at when it was just smoke coming out from under the hood. But by the time I found the fire extinguisher in my car, the front of that car was engulfed in flames. I keep it more available now.
I knew a guy who wanted to do his own wiring for the radio. He used all red wires and forgot which was which, so he connected battery plus and ground together, filling the car up with smoke when the turned the ignition.
His main mistake was no fuse.
I’ve seen similar. Color coded wire didn’t help.
The other mistake was using the wrong gauge of wire – too thin – so the fuse would not have helped; but that’s what kept it from becoming a total loss. The wire only got smoking hot and not flaming hot.
Fire risk increases dramatically with age, and many EV’s don’t have a high age yet.
The Mercedes Citaro bus has a design flaw which (according to our workshop manager) “guarantees a fire after 8 to 12 years”, to such an extent that in Roma (250 bus fires in 5 years) these buses are nicknamed “Flam’bus” [https://www.agi.it/cronaca/news/2021-10-05/misterioso-fenomeno-flambus-roma-bus-bruciati-14080752/]. The culprit: A diesel line for the heater being hung such that it will chafe through with vibration, then spray diesel over exhaust parts.
Ironically, a very similar fault has burnt down at leas one and possibly two electric! buses (with a diesel heater) in the Netherlands.
I wonder what will happen to high voltage lines after years of vehicular vibration and possibly road salts and moisture ingress. I expect non-battery fires will rise with EV’s as the fleet grows older.
Just drive a diesel. Bio, synthetic or fossil, no issues like gas cars or EVs.
Wasn’t it a diesel Range Rover that started the fire that burned down a Luton airport carpark? Turns out diesel does ignite if it’s sprayed onto a hot engine by a faulty fuel line.
It was indeed.
It also doesn’t help that modern fuel tanks are usually made of plastic, literally “adding fuel to the fire” when they inevitably melt in the conflagration.
It was a range rover.
The cheapest way out of that was the fire.
Sure car parks aren’t cheap, but compared to keeping a Chinese made English car running?
So here’s an interesting additional data point on how to make lithium ion battery packs safer: https://ntrs.nasa.gov/api/citations/20150020936/downloads/20150020936.pdf
I have to admit, I haven’t read the whole thing, as I was more interested in how much battery power a NASA EMU space suit has, but it looks like there’s some really interesting thought and design going into this problem. And, I have to admit that the idea of being in a space suit with an exploding lithium ion battery is a lot scarier than being in a car with an exploding lithium ion battery – even if one of those scenarios is inordinately more likely
You need a safe way to disable and fire-protect the parts of the electric battery in case there is fire (external or from an elemwnt of the battery). Disabling is to disconnect the battery in smaller parts to avoid short-circuit that will reignite the fire and dire-protect is to shield the remaining elements from the fire.
I suggest both to be done with expanding foam that contains both co2 (expansion) and h2o (termal protection).
Once a cell is in thermal runaway their is almost no stopping it.
Hold the whole pack together with low temp solder.
Include steam gen and cell launch tubes.
So the flaming cells are launched into neighboring lanes, through windows etc.
Enough e-cars and the system would go prompt critical!
Fun!
Battery packs would look like zoomy headers for a 2000 banger.
This sounds a lot like Star Trek (“Eject the core! Already done it!”).
Regulations just pushes prices up and of course is a great business, since government take his share of the dough through it.
What will actually works out is the evolution of the technology coming around as the time goes, as it ever happened.
And sorry for you guys that trust so much in your regulators, I know all the discourse you guys have in response… We all need to trust something to feel safe, that’s ok.
I like EV’s. I have an EV moped (not Chinese cheap rubbish). So cheap to run. But what the world really needs is less cars. All cars catch fire, thermal run away is for fossil cars too. When I was a mechanic, most engine bay fires started after the car had an over heating problem. If only owner had got that fixed them may still have their car.
The real issue is big business always fights regulation and wants less of it. But it is this very regulation that protects the consumer from dangerous products.
What does make me laugh a little, is how many anti EV people that rant about EV fires sleep at night with their phone on charge next to them.
Not always. A lot of the regulation we have is big business lobbying for laws and rules that are designed to hurt their competitors more. It’s a feature of crony capitalism – corporations build up the regulatory environment to suit their business in particular, setting up thresholds and barriers for smaller competitors that they themselves can get around easily.
It’s a limited risk for batteries in the 5-10 Watt-hour category. I have mine on a metal table. I’m acutely aware of the risks and charge all my larger battery packs in a metal box.
new vocabulary added to brain: to mope – reduce vehicle part of total moved mass …. no, wait, I misread that. On the other hand … keep the idea for later?
Wrong li-ion type.
another aspect of this is that electric cars are too fast and their speed is too ungoverned. there was a famous incident in coral gables 2 years ago where a young man driving a tesla at about 90mph in a residential area hit a small bump on the road, went airborne, and crashed into a tree, resulting in a spectacular explosion. and then a few months ago almost the same exact crash happened in my small city! there’s no reason at all to make a car that can go 90mph outside of a freeway, but tesla did it anyways and the resulting spectacular crashes draw a lot of attention to exploding battery packs. doesn’t matter how safe they really are, the cameras will go where the young men are making novel boom-booms.
of course the same thing happens with gas cars but with the tesla it’s just a little easier to be that stupid, and a lot more exciting for the media.
If anything I’d have thought EVs have lower top speeds than ICE cars. When you have a single gear ratio and want to avoid cogging at low speeds you pick a ratio where the motor turns faster at low speed but tops out at 90 or 100mph. ICE already has gears so it’s trivial to add another and top out well above 100. 155mph is a common limited top speed.
The top speed of an electric motor isn’t really a hard limit – you simply start losing power as the motor coils begin to impede current flow past a certain speed. If you have enough voltage available at the battery/controller and your motor is way oversized, you can force it to go faster and faster until air drag exceeds the power you’re able to push into the motor.
There’s also certain types of DC motors without permanent magnets where the field coils are wound in parallel and series with the rotor coils. Wiring it wrong creates a motor that has no speed limit. It will intrinsically change the field current to increase speed indefinitely until the rotor explodes from centrifugal forces.
At above about 150 mph your typical car makes enough lift to impair steering.
That’s where you actually need/want ricer type addons.
You want a high gear ratio diff. For the launch. Lower top speed. More RPM at highway speed. But tire smoke must be served.
That is unless your English.
In the old days fast English cars were tuned for salt flats (and towing), American for 1/4 mile and German for Nurburgring.
These days they’re all tuned to extract maximum maintenance dollars.
But English cars are made in China.
That’s not a problem with electric cars. ICE cars can go fast too. That’s a problem with reckless drivers.
First: F the nannies. F the state ref. F CARB. V8s forever!
But e-cars are generally fast cars you have to drive slow.
Even the few that are truly slow enough you can drive the piss out of them aren’t fun.
Not a Honda 600N in the lot.
I’ll add that part of the problem is it’s really hard to get water on/into a burning EV battery. The battery packs are sealed, lack any reasonably sized voids/channels around them that allow water through, and are at the very bottom of the car. Best you can do is splash water on the bottom, or hope they burn through the floor pan and allow water to be applied from the top.
You can’t put out a lithium fire with water, anyway.
I’d guess that enough water could keep adjoining cells cool enough to limit the fire spreading.
That really seems like one way to attack the problem: how do you prevent a single cell on fire from spreading to all its neighbors? Perhaps a system could be designed to eject portions of the battery that are on fire, protecting the rest.
Eject them where? Instead of burning in place, would it shoot burning cells around like a roman candle?
You could just have the solder melt and the cells fall to the pavement to be raked apart.
Car’s junk, but at least they don’t have to wait for days.
Where is the fun in that though?
I want to calculate the cross section of a Tesla with respect to flying cells.
Would an ICE car act as a moderator? A dry field?
In any case, you don’t solder cells.
They don’t like the heat.
They are spot welded.
You’d have to have low temp solder holding the conductor strips together. And some sort of burn through/fall off weather cover.
Just far enough away from adjacent cells/modules to prevent the fire spreading. They don’t necessarily have to detach.
It’s a tightly packed box that is closed off from the underside, so the only direction you could eject the burning cells is up at the passenger space. That’s another no-no since all the plastics and fabrics burn so well it only takes 2-3 minutes for the entire car to light up.
What could be done is explosive bolts that drop the entire battery out and shear the cable harness, so the car can roll off the burning battery and expose it for the fire hose.
Like I suggested above. Low temp solder holding it together.
Steam gen and a tube to launch the burning cell into the neighbors car/house/cat.
45 degree angle should be optimum for range…unless car was moving…then tricky.
KISS. 45 it should be.
But if a BEV is burning, and the ffiremen are just standing there, it’s not good for publicity.
So, they spray on the water after they’ve run out of foam.
“Although battery fires in electric cars and two-wheeled vehicles are not a common phenomenon, they are notoriously hard to put out, requiring special training and equipment by firefighters.” – I have been told by a volunteer firefighter in a place that doesn’t get expensive equipment that the “training and equipment” was essentially “hey guys make sure you keep soaking it with water for awhile to dissipate the heat so that it doesn’t relight”. So this “fact” that firefighters are powerless to deal with battery fires isn’t as universal as people seem to think. Also, firefighting is a career with ongoing training as a matter of course, and so naturally during their regularly scheduled training they are going to mention EV’s.
Now, this does mean you’re stuck onscene for longer, because you can’t get it to stay out until the energy is depleted. And it’s not like you have access to the battery; you’re watering the whole thing. But once any humans are safe, as long as there’s nothing else going on at the same time, the big thing is just to not let it develop into anything more while waiting for it to run out of steam. I think it was described as something like fighting a pole transformer fire in which you for some reason have to wait a long time for the power to be cut off after the fire starts.