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Comment by Animats | Hacker News Reader

Maybe lithium-ion batteries in mass-market vehicles aren't such a good idea. We may need a battery technology that can survive poor maintenance less than perfect battery construction, and low-cost vehicle designs. Tesla had to put a titanium plate under their battery. That's not a mass-market solution.

BYD is converting over to lithium iron phosphate, which is much better behaved when damaged. Toyota is working on solid state batteries, which hopefully don't catch fire.

The NYFD reports over 55 electric bike and scooter fires so far this year.[1] Two deaths, 60 injuries, including 18 firefighters. Fires destroying electric bike shops are a thing, with one fire expanding to all the batteries around. All we need now is for a cascade auto battery fire in a parking lot. Or, worst case, a garage under a building.

Boosted skateboards used to use lithium iron phosphate, but were just too expensive.

[1] https://www.nydailynews.com/new-york/nyc-crime/ny-e-bike-sco...

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> Fires destroying electric bike shops are a thing, with one fire expanding to all the batteries around. All we need now is for a cascade auto battery fire in a parking lot. Or, worst case, a garage under a building.

As a firefighter let me add some context: Electric car fires are no big deal anymore.

Yes, they're not "out" when there's no more flames or smoke for the moment as the damaged cells might be reacting further and further.

Easy solution: Put them in a tub full of water for at least 24 hours, better monitor the temperatures of the water and only lift them out once it has not changed for a few hours.

Most fire departments nowadays have some kind of container that can be filled where you can lift the car into. If not, they'll call somebody who has such a container, like landfills and alike.

Yes, the car is done after that, but it wouldn't be different with a gas-powered car either.

This might have been new five years ago, but so were solar panels 20 years ago and everybody was worried that nobody could ever extinguish a fire under solar panels.

Real life has shown, that you just rip the panels of the roof (if they're not already burned when we arrive) and work as if nothing has happened (simplified, but not too far away). With eletric cars you sink them. Easy as that. "Improvise. Adapt. Overcome." it is.

Also: garage fires are special in itself due to the lack of head room and "place to go" for heat, smoke and fire. It's not really a big difference after that. Basic rules of engagement are to be followed: Get the fire out and then the cars out of the garage. WIth electric cars you'll have to sink them once they are out of the garage, obviously.

Please stop fearmongering with "electric car fires".

> Electric car fires are no big deal anymore.

> Easy solution: Put them in a tub full of water for at least 24 hours

How is this not a big deal? This forces firefighters, which sometimes are small departments without a lot of resources, to transport the cars. It's a nuissance if it's 1 car, but a parking lot caching fire would be an absolute nightmare.

If a car catches fire in a narrow street in the middle of a city, and it jumps to just a few more cars, you may have a massive issue.

It's great that you guys have adapted to this, and I'm sure we will learn how to make battery powered cars safer. This is the early-ish stages of a new technology, which are always rocky times... but it is still a big deal which shows how early it still is, which would be fine if we didn't need to stop using gas ASAP.

PD: I tried not to sound snarky but I may have failed. I intended no snark. I'm actually asking, how can this not be a big deal? Because it sounds like a big deal to me.

> How is this not a big deal?

First of all sorry for my English, I sometimes fail to find the right words, so it's sometimes hard to explain what I mean.

It's not a big deal in the sense that you'll call the control/dispatch center and tell them that you'll need a tub for an EV. They'll then take care of getting it to you and that's what firefighters worry about.

How the car leaves the place? None of the firefighters' business, at least here in Germany.

Of course there are lots of things in the aftermath like how to recycle the water from that tub as it might be contaminated and needs special treatment, but that's a problem for someone else and possibly already solved somehow.

> but a parking lot caching fire

Yeah, that would be shit, but it could also happen today with gas-powered cars. I've experienced something similar myself once with a used car sales lot. It was somewhat frightening as the fire spread to multiple cars very fast because of the large amounts of heat.

In the end we concentrated on cooling the unburnt cars at first, and only as a second measure slowly fighting and extinguishing the ones that already caught fire when reinforcements (lots of!) had arrived.

Would you handle it differently with EVs? Yes, probably, you'd also need lots of tubs.

Would it be completely differently? No. Cars are, once burning, very nasty to extinguish, no matter how they are powered.

I wouldn't fear an EV more than a gas-powered car if I would get called right now.

I think your thoughts speak to how public services operate in US verus other western countries.

In the US, such a process would (in my naive understanding)cripple my small-mid sized coastal towns FD, and throw the town leadership into a headspin for 20 years until the next solution is paid for by the next group of decision makers.

It's very possible that the resources (tubs) for a large amount of cars, as in this scenario, would not be available. Even if it's a yesterday problem in the operational level, the logistics look fragile.

firefighters are tough people, they had procedures for gasoline fires, now they have them for electric fires. not a big deal.

They do require a lot more water to be put out though.

> "Improvise. Adapt. Overcome." it is.

And here is the problem: most fire departments are horribly underfunded, meaning their machines are old, water tankers don't have enough capacity, water lines are un(der)maintained and the firefighter training has been ... spotty to put it lightly.

Don't know where you're from, but for Germany this is mostly solved, but those tactics are obviously still "new" for most and need to be refined, yes.

edit:

> They do require a lot more water to be put out though.

As OP was mentioning garage fires, I was expecting urban neighborhoods, where getting enough water should (hopefully) not be a problem in 2021.

> Don't know where you're from, but for Germany this is mostly solved

German here as well. For the Berufsfeuerwehr (for the Americans here: professional, full-time firefighters in big cities) yes, for Freiwillige Feuerwehr (volunteers, mostly in rural areas) not, which has been the subject of numerous media articles (e.g. https://kommunal.de/feuerwehr-fehlen-einsatzkraefte).

> As OP was mentioning garage fires, I was expecting urban neighborhoods, where getting enough water should (hopefully) not be a problem in 2021.

I was talking about electric car fires in general... and in rural areas, that is a problem (see e.g. https://www.nordkurier.de/uckermark/kontaminiertes-wasser-be...).

Anyway I'm not interested in fearmongering, just pointing out that even in Germany the situation isn't as decent as one might hope - and the US is even worse off.

I see you haven't lived in a mega-city like Karachi. When I lived there (some years ago, admittedly, but I don't believe things have improved much) we were lucky to get mains water for a few hours a couple of times a week at some seasons.

What is the problem with solar panels and fires? What happens when a house with a Tesla Solar Roof is on fire?

> What is the problem with solar panels and fires? What happens when a house with a Tesla Solar Roof is on fire?

When solar panels were new, firefighters were afraid, that classic methods will no longer work and that lots of houses would burn down, because the solar panels would be a solid, impenetrable "shield" against the water from the outside.

Turns out that solar panels will melt due to the heat before the firefighters arrive (for large fires where you have to extinguish from the outside), have killswitches, can be ripped from the roof when using a ladder and a wooden pole with a hook at the end... In the end it was just fear of this new and rather unknown technology.

Also tactics have evolved. Your main path to the fire will be from the inside, especially for normal housing fires, as you want to get as close als possible to the fire so you'll have to use as little water as possible. This lead to a steep decline in the use of "attacks from the outside".

Those will only be necessary for very large fires. In that case the panels are often gone, as already mentioned, or the house is a total loss, so destroying the panels forcefully is not that bad if you really need to do it.

Tesla Solar roofs will probably behave like any other panel/tile and can be penetrated with the right equipment or will break down by themselves as a result of excessive amounts of heat. I don't see big problems here.

From my recollection of a documentary I watched a few years ago: You can cut power to the burning building if the fire hasn't already destroyed the circuit(s) itself, solar panels though are not bound to the utilities thus can't be shut off remotely and could give electric shocks to the firefighters/left-over occupants. IIRC there were some nasty accidents that happened like this.

Well, if the manufacturer says I should park my car 15m away from others due to spontaneous fire risk...

I don't understand this at all. Right now I'm in the second recall with my Hyundai Kona EV. They have found that there might be a problem with the battery packs, so ALL Kona get a new one where the bug is fixed.

Might take its time till they are done, but they did not tell me to park near a river or something, in case the car catches fire. So either GM is even more cautious or just stupid.

Given GM's history between recall lawsuits in the past and "activist" shareholders in the present, I'd lean way more towards "more cautious". GM is an American company more prone to certain types of US lawsuits than other manufacturers and a lot of their PR has always been full of CYA, and also currently in a multi-year battle against some shareholders trying to intentionally tank GM's electric efforts (presumably so that Tesla "wins"?).

The problem here is the form factor of the cell as much as the chemistry. Pouch style cells are very difficult to regulate temperature in. This is a key reason why other automakers like Tesla use the small cylinder cells. Chinese companies like BYD have always used lithium iron phosphate. It has less energy density than lithium nickel batteries like NCA and NMC, but is cheaper. The patent was never taken out in China and the key patent expires for the rest of the world in April 2022. As much as 3/4 of vehicle batteries might end up being LFP. Improvements in the chemistry and less need for cooling systems and packaging mean its disadvantages aren't so glaring. Plus there aren't enough nickel mines to supply the coming avalanche of demand. Lithium, iron, and phosphate are plentiful.

FYI nickel is plentiful and unlikely to ever be in shortage. It's just so cheap right now that most nickel deposits are "non-economic", and thus not counted as part of proven reserves. The same thing is true with uranium for example.

see here for the difference between resources and reserves,

http://minesqc.com/en/informations-sheets/what-are-mineral-r...

We are currently extracting 2.5 MT of nickel a year, from reserves of 94 MT. Resources are estimated at 300 MT, which is definitely a lower end, as prospecting tends to concentrate profitable ores. If the price of nickel went up, we'd see more resources becoming reserves and more discovery of new resources.

If batteries are easily swappable with minimal tools, then a lot of range concerns go away as well. I think battery ownership and care needs to be decoupled from the vehicle. I also think the federal government should enforce interoperable batteries between vehicle brands.

The cars shape and structural components are designed around the battery. The cars software, motors, charging electronics, software, cooling systems, etc are all designed for the specific battery. The battery eats up a significant fraction of the cost of the car, and the systems designed around it a significant fraction of the remainder.

Asking for interoperable batteries between vehicle brands is like asking for interoperable engines between vehicle brands, it's ridiculous. The government should not be saying "hey, that $xx,xxxx item with a million constrains and optimizable variables, why don't you make it meet this arbitrary standard so people could theoretically put it in another chassis that wasn't designed to let you optimize it as well as possible".

Certainly no one should expect to be able to swap the main batteries that are embedded into the chassis of the car. The total weight of the batteries in a Tesla are around 1200 lbs.

But it seems like there could be a hot-swappable portion of the battery, kind of like a separate "reserve tank" (although it wouldn't actually be reserved).

Some back of the envelope math says that if 1200 lb battery gets you 250 miles, a 200 lb hot-swap battery would get you 40 miles. Possibly enough to get to your next destination.

> a 200 lb hot-swap battery would get you 40 miles.

According to one report, for a Tesla Model 3, a supercharger can add ~100 miles of range in ~10 minutes. It's hard to see how any improvement over that could possibly justify the immense additional complexity of physical battery swapping for only 40 additional miles of range.

https://insideevs.com/news/506520/tesla-model-3-supercharger...

Does the Supercharger network come with a fleet of drones that can autonomously repair a charger in the middle of nowhere, that broke down one late evening of a particularly snowy winter Sunday?

That said, it's probably a UX problem. Once EVs stop competing on range so much, it'll make sense to just designate the last 10% of battery as "reserve" and not count it in the battery level indicator.

Somehow gas pumps get repaired/maintained in the "middle of nowhere" today. Eventually the economic incentives will align that that the charger networks get maintained no matter where they are.

Arguably it should be far easier to get those economic incentives aligned as chargers are far simpler mechanically (they are just plug sockets with weird over-engineered male adapters) and most of what breaks on them is either vandalism or a small subset of existing problems of gas pumps: credit card reader malfunctions, display/screen problems, internet connectivity issues for account management/credit card transactions. (All the human UX points of contact.)

> Once EVs stop competing on range so much, it'll make sense to just designate the last 10% of battery as "reserve" and not count it in the battery level indicator.

Most already do (even while still competing for range) because it's a battery maintenance requirement. Li-Ion cells generally don't like being 100% full, especially not for long periods of time, and sometimes have a preferred "directionality" (ie, a cell should only be charging until it hits 100% and then you can draw from it and vice versa once you start drawing from the cell you should keep doing so until it hits 0%) so battery controllers already have to do a bunch of math to keep a "reserve" so that they don't violate "directionality" (you always want cells in the "charging" direction available even while driving for regenerative braking storage, for instance) and don't generally hit 100% charge for long rest periods, but instead 95% or so.

I thought we were comparing fast charging to battery swapping. Surely a machine that physically swaps out a battery is going to be significantly larger and more complex than a supercharger, and therefore also much more likely to break down..

No but there are always multiple supercharges at each station.

> it'll make sense to just designate the last 10% of battery as "reserve" and not count it in the battery level indicator.

Very questionable? Why would you do that?

We don't do that for gas cars either.

Every ICE car I've ever driven did exactly that with the 'reserve' where the needle is already at (or below) the zero line but you still get about 50 km of range.

I've been wondering about that with the cars with digital displays, particularly the ones that report your estimated remaining miles.

I once, embarrassingly, found myself on the highway with an empty tank of gas and 20 miles to the next gas station. I watched the estimated miles remaining indicator tick down mile after mile, ticking precisely my passage. At 3 miles estimated remaining, I pulled over because there was a very wide safe shoulder, and I didn't want to putter out in a less-safe spot.

I don't want to try the experiment of letting it tick down to zero and seeing if I still have 10 miles or so left.

Yup, exactly that.

I think the use cases for field-swapping a (part of the) battery pack are the same as for carrying extra fuel canisters with you, which I can only speculate about, because I've never been in such situation with an ICE car.

What about small generator and a canister of gasoline?

That’s what BMW did with their i3 REX models: a scooter engine and a tiny tank, hooked up to the electrical system. Turns out though that the extra weight impacted the performance without adding much in the way of range to the point that it wasn’t really worth it.

A 2000W inverter generator could give a Chevy Bolt an extra 14 miles of range after 3 hours of charging. A 240V generator could shorten that time or lengthen the range but would also be larger and take up more room in the car. Carrying gasoline in the back of your car all the time in case you run out of battery is somewhat dangerous. The generator means less cargo space as well. For a long trip to the middle of nowhere it may make sense to carry a generator and some gas. For a trip into town it may not.

> Asking for interoperable batteries between vehicle brands is like asking for interoperable engines between vehicle brands, it's ridiculous.

Engines are interoperable to a large degree; you can switch out the engine+ecu of your car for the engine+ecu of another car more easily than you'd think because the majority of the effort will be in changes requiring an adapter plate and shaft for the transmission.

There are hurdles that make it harder (for example, auto transmissions have software that expects a particular set of engine characteristics), but by and large most engines are isolated enough from the rest of the car and the drivetrain that you don't need to worry.

Batteries are to the same degree. if you really wanted to, you could take a bunch of liquid cooled Tesla modules and fit them in a old leaf, when it’s batteries degrade.

It's not ridiculous but it does lead to this conclusion: That there is probably a single optimal "skateboard" type design. Manufacturers are converging on this anyway.

https://en.wikipedia.org/wiki/Skateboard_(automotive_platfor...

Then the real truth that no one wants to hear, is that there is no need for so many different types of passenger vehicles.

It's astonishing how similar all cars are becoming, outside of the superficial stuff. For a reason. Convergence on the optimal solution.

They are also optimizing for superficial appeal to customer, not 100% functionality.

If that’s actually true there will be one player to rule them all. Tesla essentially been selling same car for a decade.

This is nonsense. That's like saying 'everybody converging on a 4 wheel design'. The details of how the platform is built and integrated is still very different.

> Then the real truth that no one wants to hear, is that there is no need for so many different types of passenger vehicles.

Good that we have you to tell us what vehicles people should drive.

> Asking for interoperable batteries between vehicle brands is like asking for interoperable engines between vehicle brands, it's ridiculous

No, it is like asking batteries for radios follow the norm (so that they can be swapped), or petrol to be the same for all cars, with the same pouring mechanism (a round hole), or USB connectors to be the same between devices.

Swappable batteries preclude the large weight savings of a structural battery that is an integral part of the car's chassis.

I'd say it should be possible to have a certain degree of compatibility just like I expect my GPU to work on any of the MB on the market supporting PCI-e(Space and cooling issues asside). The battery should be just a battery with a protection system. Charging and BMS should be separate and replaceable along with the battery. The OS of the car should support x number of BMS systems with a unified protocol.

You want a Li-Ion pack? This BMS and this shielding are required. You want Lead batteries? This BMS needs to charge it. Do you want that new battery tech? You need the new BMS for it and an OS driver for the BMS. Plug it in and it's done.

The battery is the most expensive part... which susceptible to wear, abuse and fraud. (and fire). Making them easily swappable with minimal tools means they'll be easily stolen.

The negative replies to this are largely valid, but ignore the fact that we can have multiple strategies at the same time.

I for one would love to be able to take my battery out, swap it, have a few so some are always on solar charge. Be able to take one onto the boat. Use a new one for higher performance special occasion driving, and an old one for bumper to bumper slow commute which I can wrong every last mile out of. Have a few which default to home backup and can support the grid.

The highly optimised around the battery argument is very good. But it doesn't mean that we can't also have a company focusing on interchangeable batteries with a third party market.

Let the buyer decide. Neither solution will get 100% of the market, or zero. Why write one off right now with confidence when both could have a healthy market for the hugely diverse users (ie not just SV nerds)

The fed enforcing interop wouldn't be black and white. Just like Mercedes are allowed to sell super low MPG AMG Sports cars because they also sell lots of small city cars. The fed could encourage things in this direction without being black and white and mandating 100% of batteries be replaceable.

I think the downvotes of the parent comment here aren't what downvotes should be for. He or she brings up a very interesting point

Literally nobody is arguing against some companies being allowed to do that.

And Nio does in China.

Easily, yes, minimal tools, no.

But a 93 second full battery replacement for the Model S:

https://yewtu.be/watch?v=H5V0vL3nnHY

The people I know with electric cars charge at home the vast majority of the time. Swapping adds a lot of complexity and cost in the pack design. NIO is doing swaps as another commenter pointed out, but more customers in China live in apartments. In the end, I think charging stations will be ubiquitous, even for apartment dwellers, and swaps will be rare.

They are too heavy to swap them by hand

The comment you replied to said minimal tools.

In practice this would probably mean something like: a vehicle hoist, a suitable lifter, a couple of sockets and a racket handle, and a screwdriver or two.

Tesla actually had a battery swapping machine at one point, I think it was at the Kettleman City location. There's no reason the battery and charging infrastructure can't be leveraged for all passenger vehicles. The battery on your electric vehicle should be like the propane tank on your gas grill - just swap it out when you need to. (This doesn't preclude recharging it)

Not to mention, when the battery reaches the end of its normal life cycle. Just goes straight into the recycling pipeline.

Tesla's swapping machine was just for tax credits. It was never built to be something they'd sell to customers. They built that one demo location and then abandoned battery swapping completely as not viable.

If they legitimately cared instead of faking it they could probably do better. Especially if the target is a maintenance-style machine setup rather than a 30 second gas station rival setup.

Nio's cars support battery swaps:

https://electrek.co/2021/07/09/nio-plan-open-battery-swap-st...

You can rent the batteries and upgrade and downgrade the capacity as you like. It also makes it easy to replace the battery in the future if you buy it outright.

They offer 70 and 100 kWh packs now. They're aiming for 150 kWh packs next year:

https://insideevs.com/news/465188/nio-150-kwh-solid-state-ba...

might want to put it into context though... there are on average 160,000 passenger car fires per year and about 360 deaths due to that. i'd like to see that figure broken down per 100k miles driven or per 100k cars of the type but i can't seem to find that easily.

https://www.nfpa.org/vehiclefires

Yes, but an important part of that context is that electric car fires also burn longer and hotter and take significantly more effort to put out. Too little water can actually make the fire worse.

Annecdotally, my recollection from other articles is that electric cars do in fact catch on fire less often. But it also seems like they may be more difficult to deal with. This may change as EV's become more mainstream & fire departments adapt: Graphite may be effective in putting out these fires, and maybe it will become a common tool in fire departments.

For the time being, rare or not, they post a much larger problem to deal with when they do occur.

Yep. Moreover, the issue isn't new cars today.

You know when you saw that old Chrysler Grand Caravan burning on the side of the road, and you hear the story that the person has been holding it together solely with thoughts and prayers and maybe $500 between tires and oil for the last 7 years of its 19 year life?

That's the current inevitability. I'm not worried about someone's 6-month old Bolt or 2-year old Model 3. The issue is when we're eventually talking about a 22-year old Model 3 that's had 13 years of deferred maintenance, is totally clapped out, and is only on the road because someone paid some mechanic off to look the other way during a state vehicle inspection for the past 5 years.

Germany is starting to standardize on towing an electric car away to dunk it in a tank to ultimately handle fires.

> and is only on the road because someone paid some mechanic off to look the other way during a state vehicle inspection for the past 5 years.

Making mechanics liable - maybe jointly as a business and an individual - for their failure to inspect vehicles properly would be a pretty simple mechanic to reduce this risk.

These inspections are nothing but pointless revenue generation for the state, checking for the check engine light and inspecting 1 wheel at most usually. Lots of states don't even have them.

In Germany they are very serious about vehicle inspections, and insurance requirements.

Didn't the big German auto manufacturers literally develop the hacks to bypass diesel emissions inspections? I'm not sure I'd hold anyone up in a pedestal on this score...

Those cars still passed the inspection. Which means they were physically sound. A battery isn't going to shift into an alternate mode where it becomes a spontaneous fire hazard.

Those have nothing to do with each other: Germany indeed has a company level corruption problem (especially in combination with the conservative party), but pretty low corruption at the citizen level, i.e. where vehicle inspections happen.

They got caught.

Not by any German regulator or agency.

That sounds more like an argument for effective inspections being universally required more than anything else? Apologies if I've misinterpreted.

We get by fine without rigorous inspections, and they amount to a regressive tax like a lot of other fees related to keeping a car.

Death by burning from an exploding battery from an uninspected, poorly-mainteained car in the garage of your shared low-rent apartment building is also a regressive tax.

I'll take the inspections.

It's not like states without inspections have an endemic of exploding cars as it is. I don't think the justification for inspections is really there.

Fuel-based cars tend to burn after an extreme adverse event, usually a collision.

Battery fires are more frequently spontaneous, or occur during charging.

How many barbequed children do you find an acceptable number?

Battery fires usually happen after collisions too. Fires while charging are rare but they grab headlines because they're novel.

I think trying to use inspections to solve that is a case of barking up a really stupid tree. In the case of EV charging fires there's not really much a mechanic can inspect that some electronics cobbled onto the pack couldn't. In the case of battery pack damage an annual inspection isn't going to do much good since most of those cases will cause problems before that or not at all.

"Parked Teslas Keep Catching on Fire Randomly, And There's No Recall In Sight"

https://www.thedrive.com/news/28420/parked-teslas-keep-catch...

Article list 9 cases. None involved accidents. Several were during charging, one during transport (on a flatbed truck).

All are of

In Ireland, roughly half of the vehicles going for the NCT fail on the first try, and ultimately about 5% don’t pass at all after retries.

Of that, I’d say half of the initial failures are simple things that don’t require a mechanic, (dead bulbs, bad/low tires) and the rest require a me hanic to do something.

My state has inspections, but does not charge for them.

If it’s a Chrysler product it doesn’t need thoughts prayers or old age to spontaneously combust. A brand new one will sometimes so it all on its own due to bad design

Some countries have mandatory regular inspections for critical vehicle functionality like brakes. We will probably require EV battery checks like this as well, if the BMS / firmware is not enough to keep the battery pack safe.

Safety inspections are close to worthless for safety on a macro level (they are great if you own a BHPH dealer or are a government regulator trying to give shops a reason not to fudge emissions inspections though).

You implement mild inspection laws and they do nothing because people can just pay the fine or whatever.

You implement invasive inspections where people are rich and they do nothing because rich people already don't drive on bald tires and whatnot.

You implement invasive inspections where people are poor and you create incentives to circumvent the law and hardship among those who don't ignore the law.

Mechanical failure is a negligible cause of accidents and injury so applying lots of effort co chase something that's only a source of the minority of problems is kind of a fools errand to throw a ton of societal resources at it.

If inspections really make the roads safer it would be an insurance thing and you'd see differences in premiums that reflect differences in law, insurers setting up their own programs where none exist and lobbying states for inspection programs. You basically never even hear a peep out of them about safety inspections unless it's in the context of getting people to upgrade to a newer car with better safety tech. Contrast with intoxication, distraction and driver training which are issues that insurers and their lobbyists constantly weigh in on.

GP covered that: "(...) and is only on the road because someone paid some mechanic off to look the other way during a state vehicle inspection for the past 5 years".

> Germany is starting to standardize on towing an electric car away to dunk it in a tank to ultimately handle fires.

I suppose if the problem is widespread enough, every city will have a mobile dunk truck at the ready for electric vehicle fires.

And what do you do if those fires cause other things to burn in the vicinity?

Same thing you do when an ICE car sets a building on fire. Apply water and put it out.

Except for an ICE you only need to dump about 300 gallons on it. For an EV, it can take 24 hours to get the thing fully dealt with.

That's only relevant for the EV itself, not for the stuff it lit on fire.

You put out the fire, then dunk the EV in a tank when it's out to keep it from reigniting, while not having to monitor it.

Bring the regular truck filled with water to hose it down.

Not if, when.

This is yet another good reason to decouple the battery from the rest of the vehicle. Hit the emergency release, battery drops out of the car, and push the rest of the vehicle away.

I kind of hope that gets to be an (infrequent) problem.

As it is, I've lately been wondering about what happens to 14 year-old electric cars with dead batteries that cost more than the car is worth.

People like me buy them for $500 and put the motor in a grass kart

I had no idea what a 'grass kart' was, so I looked it up.

Cool stuff! And thanks for repurposing the motors.

Towing the car in a tank seems a sensible solution, but I'm wondering if it wouldn't be simpler to tow the tank near the vehicle, lift it and dunk it there?

It could be hard to get a car up into the tank... connecting a winch might not be possible due to the heat, but I wonder how they get around that to tow it?

Also, needing to plan for larger vehicles like a pickup truck would mean > 4,000 lbs of water to submerge one, base an approximate dimensions of such trucks & the corresponding volume of water.

Than again with batteries generally in the bottom of the car, maybe you'd only need to submerge a few feet?

I can definitely see the need for new emergency response equipment in the EV future.

> It could be hard to get a car up into the tank... connecting a winch might not be possible due to the heat, but I wonder how they get around that to tow it?

Seems like something similar in design to this would do the trick, maybe with sufficiently thick steel plating on the side:

https://www.youtube.com/watch?v=GaYN6yC4bnI

> The issue is when we're eventually talking about a 22-year old Model 3 that's had 13 years of deferred maintenance, is totally clapped out, and is only on the road because someone paid some mechanic off to look the other way during a state vehicle inspection for the past 5 years.

Except that the 22 year Model 3 also has a computer inside the battery that should be keeping things in check. Assuming the battery can even hold any charge at that age.

And said computer was likely receiving software updates and sending telemetry for most, if not all, of that time.

Or it have been hacked either to send fake data or no data at all... Knowing the general level of security in industry and even with some high end smartphones, I expect it to happen.

For everyone interested, there is an interesting study to be found researching EV vs gas driven car fires [1].

"Nevertheless, existing test results have revealed that the heat release rate of EV fire is comparable to that of the fossil-fuelled vehicle fire, while EV fire may release more toxic gasses like HF from burning Li-ion batteries."

[1] https://www.researchgate.net/publication/338542510_A_Review_...

> For the time being, rare or not, they post a much larger problem to deal with when they do occur.

It seems to me that being harder to put off but occurring less frequently, and most importantly not exploding (leaving significant amount of time for occupants to get out, if they are able) is a pretty good trade off.

Also a gasoline car actually exploding is exceedingly rare. It generally takes a bit of effort to get gasoline to explode, rather than simply catch on fire. The tiny explosions that occur in the engine are only possibly due to gasoline being aerosolized into a fine mist.

Take a gas can with a soaked rag & trail of gasoline leading to it & set it on fire and you'll have quite a fire on your hands, but no explosion. Now, add a tiny bit a black powder to the equation to disperse the flaming gasoline into the air and you've got a small fuel-air bomb on your hands. But that-- or similarly explosive circumstances-- just don't happen with cars much at all. Pop culture, where a few guns shots result in an explosion, gives the wrong impression here.

For the curious: The Mythbusters actually tested the "shooting a gun at a gas tank explodes the car" thing, and it didn't work. It only worked when they tried it with tracers, but those are a whole different thing than ordinary ammo.

I couldn't find a clip of it, but here's the Mythbusters Wiki page for the episode: https://mythbusters.fandom.com/wiki/Car_Capers

Don't try this at home though

It could be a good trade off, it depends on more details though. Do electric car fires flame up faster, giving passengers less time to exit the car? What about toxic fumes emanating from the burning batteries? Since they they burn hotter and for much longer, are they more likely to damage surrounding infrastructure, like a bridge, before being extinguished?

I don't know the answer to these questions. They could all be "no". But before judging the trade off those are important factors to understand.

I don’t know about giving occupants more time to get out. I have seen the carpark video of a Tesla going up in flames in China.

https://www.bloomberg.com/news/videos/2019-04-22/tesla-inves...

Thing went from 0 to 110 real quick.

From an exterior perspective of a parked car certainly that would look like the case. The interior software in an operating Tesla has very loud warnings as soon as the first firewall breaks between cells which according to multiple incidents happens at least 5-10 minutes before enough cells hit critical temperatures that the entire vehicle becomes fire. Far more warning than an ICE fire.

There's probably a case to make that there should be an effort to provide better, similar software warnings for parked/"off" vehicles to signal emergency services with that extra lead time.

> Tesla has very loud warnings as soon as the first firewall breaks between cells

I searched but wasn't able to find a video of this. Any reference?

The “explosions” you hear from car fires are almost always first the tires popping, and later the airbags going off. I watched a car fire near me last year and the firefighters didn’t even flinch when the loud bangs happened.

Lithium batteries are far more explodey than modern gas tanks. Battery fires burn much hotter and faster than "regular" vehicle fires (which are generally just the contents of the vehicle burning, not the fuel).

> It seems to me that being harder to put off but occurring less frequently, and most importantly not exploding (leaving significant amount of time for occupants to get out, if they are able) is a pretty good trade off.

It's very rare to get a gas tank to explode (as others have pointed out). You need to have very little fuel (or better, none at all) in the tank before a spark will cause explosions.

Take a 2l plastic soda bottle, fill it 90% full with petrol and (with tongs from a distance) drop in a lit cigarette. I've tried to get the bottle to go bang multiple times and it never happens - the ciggarette is extinguished every single time.

Then empty that bottle until there is less than 5ml of petrol in it, close the bottle and shake it up to get a rich mixture, and then repeat the experiment (I've gotten fairly big bangs every single time, this way).

The TLDR of it all is that there is danger of explosion when the tank is emptied, not when it is full, because the fumes cause explosions, not the liquid state of the fuel (which just catches fire).

Yes, as I understand it, the fuel vapors give a relatively minor boom that disperses the rest of the gasoline enough to become essentially the second stage. Not that it takes long enough to really discern two stages: aerosolized gasoline will go up fast.

How long would you suggest those tongs should be, to ensure a safe distance? For the ones that go bang.

> How long would you suggest those tongs should be, to ensure a safe distance? For the ones that go bang.

I'm hesitant to answer in case some tries this and gets hurt.

I used a flexible claw (one like this: https://www.amazon.com/Flexible-Claw-Automotive-Mechanic-Gen...) inserted into a standard copper pipe (used for taps and other plumbing) to stiffen the spring and held it at arms length.

So, about 2m was safe for me. I also suggest wearing protection for your ears as these are really loud bangs, and protection for your eyes as well (it is an explosion, after all).

I think, given the HN community, the appropriate answer is "build a robot to do it for you"

How many of those are with the car off and at rest ?

There have been a couple of big recalls in the not-to-distant past for ICE vehicles spontaneously combusting. They have electric components too, which can short out and start a fire.

Saturn had a recall over generator fires when the car was off. When running the generator would over heat, when the car was off the residual heat would cause a fire since there was no cooling airflow.

My sister had her Chrysler LeBarron go up in flames in her parking garage.

Happens more often than you think

I would much rather my car catch on fire when I am not in it.

Well I’d really prefer it not catch on fire at all but you get the idea…

Is that actually relevant though, or just an implementation detail? Perhaps you could argue a moving car seems more potentially hazardous? But then that's only learned from extant behaviour anyway?

A car being driven is guaranteed to have a person behind the wheel. (For now...) A electric car in an attached garage spontaneously bursting into flame at 2 am is a recipe for burning a house to the ground.

The major issue in these fires is the lack of someone attentive. We can leverage the existing horn in the same way as anti-theft systems to fix that. We need a way to detect the issue, but I would hope there's a thermometer somewhere we can use to sense dangerous thermals.

Even more interestingly, the car could communicate with your smoke detectors to set off the fire alarm. It would be a great value proposition for something like Nest. It can let you know that there's going to be a fire before it even starts.

I would hope that honking the horn in case of fire is something we could achieve with a software update, but maybe not.

The pipe dream would be for the car to be able to get itself somewhere safe-ish in bad conditions. We're probably a good ways off from it, and safer batteries may take over first, but worst case scenario we may be able to program some kind of "escape path" into the cars. My car has the ability to save garage door opener codes. It's not too far fetched to be able to tell it to roll up the garage door and pull out into the driveway in case of potential fire situations. You might need an automatic ejector for the charger cable, but that doesn't seem insurmountable either.

I do agree that electric cars are more dangerous for now, and will continue to be even after the updates. We can narrow that gap with software, and even more with some integrated hardware.

It's not all doom and gloom for EVs, though.

So automated ejection of the warp core in case of a pending breach?

My dad's gas car (20 years ago) caught on fire in the garage while he wasn't there. The house was fine b/c of a a code required fire break between the garage and house. It's probably more rare nowadays, but not impossible.

Well at this rate the refrigerator will text you if your house is burning down.

In the former case there's definitely a person inside the thing that's on fire, and in the latter case there almost definitely isn't a person inside the thing (I guess once in a while somebody sleeps in their car but this isn't recommended) and that seems like a much safer situation.

Houses are replaceable, that's why people have insurance.

How is it safer for a car to catch fire in your garage while you're asleep? This is clearly the more dangerous situation.

Safer than being in a car which is on fire. That's what we're comparing here.

I still dont understand how that is safer. If the car is on fire, you can get out. I have been to many car fires when I volunteered with the FD and unless it's a wreck with entrapment, there's never any injury. In comparison, there are plenty of deaths from fires starting while people are sleeping.

Safer if you don't expect the person to get out when they see black smoke and flames coming from under their hood. Cars don't usually catch fire explosively.

Humans are replaceable, that's why people have insurance.

Just kidding.

Catching fire when no-one's around seems like it could go a lot worse than catching fire with a driver present.

https://www.nfpa.org/-/media/Files/News-and-Research/Fire-st...

56 vehicle fires / billion miles driven.

15 vehicle fire deaths / hundred billion miles driven.

The risk of lithium ion fire is very obvious and real. But to decide if this is a problem relative to the current alternatives (gasoline) we would need to compare the rates and severity of fires between the two.

Gasoline cars also have complicated parts to help mitigate their fire risk.

Not to mention the chronic illnesses and deaths reduced by taking ICE vehicles off the street.

I’ve never heard of a gas tank spontaneously bursting into flames.

https://www.nbcnews.com/business/autos/bmw-adds-nearly-185-0...

"BMW is adding nearly 185,000 vehicles to a 2017 recall for possible engine fires.

Two years ago the company recommended that the vehicles be parked outdoors until problems are fixed."

Now you have heard.

"engine fires..." not gas tanks.

Given gas cans often need a flame arrestor to keep the same happening from gas stored in garages, and that often wasn't included in cheap versions but was in commercial versions for many decades, my guess is that it happened and might still happen.

80’s television taught me that virtually every rollover accident will result in a vehicle explosion.

There are about 160,000 fires involving personal internal combustion engine vehicles per year.

I think the key word there was "spontaneous", along with the relative danger and difficulty of dealing with them. An EV fire can take 24 hours to secure. A gasoline car takes about 300 gallons of water.

I'm not saying EV fires are a bigger issue than gasoline cars. I'm saying that you cannot look merely at incident rate to determine the issue.

I would say that's an advantage for EVs. I'd rather have fires that are slow to start and slow to put out than the opposite.

I’m not sure, it’s 24 hours of constant monitoring and fire suppression from a trained fire crew. Not something that’s scalable.

So, there’s a guaranteed recipe for starting an engine fire (though from oil, not gasoline): Icy hill, and idiot drivers holding their engine at max revs for a few minutes to try and conquer them. The heat destroys the seals, oil leaks out, and combusts on the hot block.

Which makes me wonder, how would an EV handle the same poor driving conditions?

I think you'd just heat up the battery pack until the cooling system couldn't keep up, and then it would automatically limit the output to prevent the battery from overheating. Apparently racing tesla's on tracks has the same thing happen.

It's not obvious to me how you could cause an ev to fail catastrophically like that, because they do have sensors to detect overheating in the battery. I guess in theory you could also do something like catch the tires on fire from too much friction...

How many of those are due to the ICE? In my experience most vehicle fires are electrical in nature, whether it's an EV or not (the 12v system in an ICE car can still cause a fire).

Ethanol gasoline degrades older vehicle's rubber fuel lines, This has lead to many fuel fires.

Yeah, I'm not saying it doesn't happen, I'm just saying it's very infrequent in my experience (~15 years as a firefighter). Electrical issues, accidental fires in the passenger compartment (cigarettes/joints igniting trash in the footwell), and even arson are all far more common than fuel system issues.

Tesla already uses lithium iron phosphate for some Model 3s as it's cheaper (not more expensive like you claim). And Tesla has basically already solved the fire problem through careful engineering, and other carmakers will figure this out as well.

But also, car fires happen all the time. They're just normal and so don't get to the news. My grandfather died in a gasoline fire (which can happen a lot faster).

> And Tesla has basically already solved the fire problem

Have they? So why did a Tesla Model S Plaid (a new car) catch fire while being driven just a few months ago?

https://www.theverge.com/platform/amp/2021/7/2/22560662/tesl...

There are 1.5 million Tesla cars out there on the road. Most of them, nearly all of them really, are not on fire.

I understand that. But if I tell someone at work that I "solved the XYZ problem", I mean that XYZ doesn't happen any more.

If there's a claim that Tesla has "solved the fire problem", I would hope there's a good explanation for why fires still happen with the newest model delivered 3 months ago.

This was a manufacturing failure of a particular battery design. Other pouch batteries with a different design built by LG have not had problems.

Tesla is using Lithium Iron Phosphate in Model 3s and Ys manufactured in China. It's giving buyers of the SR+ in North America the option of the LFP version if they want faster delivery.

The downside of LFP is lower energy density which means an LFP Model 3 has a slightly reduced range compared to the Lithium Ion version.

The upside is the LFP likes to be charged to 100% where as Lithium Ion prefers 90% charges.

Tesla is shipping LFP batteries in it’s new cars.

I was about to correct you that it was only for cars in China, but it looks like my information was out of date. An article for others who hadn't heard:

https://insideevs.com/news/529228/tesla-model3-lfp-battery-o...

CATL sodium batteries, maybe in 2023:

https://qz.com/2041051/chinas-catl-unveils-sodium-ion-batter...

Sodium reacts explosively with water.

Pure sodium, sure.

You're full of sodium, though, and you don't explode.

As a kid I remember watching a documentary on spontaneous human combustion. That gave me nightmares for weeks...

So does pure lithium

Which is exactly why I am wondering how sodium batteries will be any easier to manage.

https://spectrum.ieee.org/sodium-ion-battery

> Sodium batteries are also more stable and safe than lithium-ion. They have a wider temperature range, are nonflammable, and there is no thermal runaway—which can cause lithium-ion batteries to catch fire—under any condition, says Pouchet.

Thanks for the actual informative link instead of the CATL press release others are linking. Sodium-ion batteries seem to have some very desirable properties over other rechargeable battery chemistries.

Has CATL substantially improved the energy density? Half the capacity on a per-weight basis than Lithium-ion seems pretty bad for EVs. Halving the range of already barely-acceptable vehicles seems pretty bad. Maybe it’s fine for short-range EVs and hybrids, but the range is one of the selling points of the Bolt.

That's not a mass-market solution

Tesla have sold well over 1.5 million cars at this point

Gasoline fires happen all the time. They just don’t get press.

No method of packing enough energy in a car for hundreds of miles of range is going to be perfectly safe. Stored energy is stored energy and any material with that much really wants to party.

It does seem that the Bolt has an issue. I’m glad I opted for the 62kWh Leaf for an affordable EV and so far I think there has only ever been one Leaf fire. It happened years ago and they have been on the market about the longest. The Bolt has slightly more range but I looked at both and liked the Leaf more. This was before I heard about fires.

> The Bolt has slightly more range but overall the Leaf is better.

I'm curious how you determined this? Everything I've seen suggests the Bolt is better in most ways, and overall. Excluding the current minor risk of fire, of course.

Not to imply I know what I'm talking about, but I really wish we could find some way to create carbon-based batteries (graphene or something) so we could develop a carbon capture -> battery process. That would be pretty damn cool.

We need to hurry up with Graphene Aluminum batteries

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