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Comment by sn_master | Hacker News Reader

Gasoline cars can catch fire too, but the EV problem is that the fires do not go out using traditional techniques and the fire can re-ignite over and over even several days after being put off.

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Gasoline cars don't catch themselves on fire overnight while you're sleeping. They do it while you're standing there, usually within reach of a fire extinguisher. And, yes, they're easier to put out.

They are still very difficult to put out. I've been to several vehicle fires (I'm on the volunteer fire department here) and they burn very thoroughly and quickly and hot. And if the magnesium catches on fire you can't use water on it.

How many EV batteries have caught fire in the manner in which you described per 100,000 vehicles sold, and how does that compare to gasoline vehicles?

I’m not a fan of speculation for things so easily measurable.

https://electrek.co/2022/01/12/government-data-shows-gasolin...

This link seems highly suspect. In one graph they seem to be comparing number of vehicles recalled due to a potential fire hazard. That is not the same as actual number of vehicles that caught fire. You might have a model with 500,000 vehicles recalled because a faulty switch caused a fire in 5 cars.

It also tries to combine data with hybrid vehicles with ICE vehicles because they also have a gas component. They don't do the same with EV, even though hybrids also have an battery component. There is no attempt to distinguish if the fires were caused by the gas or the battery in those cases.

When I see a study fudge the numbers in one area, I am suspect of all the numbers it presents.

There’s a sub-link in there to InsuranceEZ that has the data I’m referring to:

https://www.autoinsuranceez.com/gas-vs-electric-car-fires/

The orange and purple colored chart.

Eh, I'm a skeptical of how Eletrek is interpreting the data; they're talking a very broad approach of total fires in ICE vs EV, which leaves next to no room for understanding why. The National Fire Prevention Association published analysis that's more nuanced to me:

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Figure 10 shows that roughly three-quarters of the highway vehicle fires reported in the US in 2017 that were caused by mechanical or electrical failures (77 percent) involved cars with model years of 2007 or earlier. This was true for only 54 percent of the fires resulting from collisions or overturns. As vehicles age, parts wear out, extended maintenance plans expire, and maintenance can be overlooked. Consequently, it is not surprising that vehicles that are at least 10 years old are at greater risk of a fire started by a mechanical or electrical failure or malfunction.

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

On EV's, their opinion was mostly summed up as such: "Mechanical and electrical fires, the most common fires in ICEVs, become more common as the vehicles age. EVs have not yet reached the ages where these conditions are more commonly seen."

So at least for me, I'd be somewhat hesitant to take Electrek claim's at face value.

I am not sure what's your point? There's far less EVs now, and a negligible percentage of them are over 10 years and badly maintained. Also, the nature of fires is still very different.

With gasoline you can put it off using water, while for EVs water will actually make the fire worse and you'll need special compounds to turn it off.

> With gasoline you can put it off using water, while for EVs water will actually make the fire worse

Water is perfectly fine to use on lithium-ion battery fires. It cools down the battery eventually stopping thermal runaway. A strategy I've seen is to submerge the battery pack in water. There's also water additives that help dissolve some of the chemicals in lithium-ion batteries.

Note that lithium-ion (and similar) batteries only contain a small amount of polymerized lithium, unlike lithium batteries which contain raw lithium and thus react with water.

It appears you can contain EVs fires with a special blanket. Youtube "bridgehill fire blanket". It does reignite if the blanket is removed but containment will protect property. I should stop as I'm not an expert I just saw the video and report.

As for probability, why are you assuming they'll be more dangerous?

This data is per 100,000 vehicles, which takes into account the proportional number of vehicles sold.

An analogy: if a Cessna is more survivable in a crash than a jumbo jet but the jumbo jet crashes 100x less, you still want to be flying on the jumbo jet.

The point you're missing is that even after normalizing for the number of vehicles, you still need to also normalize for the age of the vehicles: the rapid growth of EV sales means most EVs on the road are relatively new.

Just an anecdote, but my friend's dad's jaguar spontaneously combusted one night and they had to call the fire department. He swore off jaguars after that lol

British cars stereotypically have electric issues, but I didn’t think that still happened.

It was 2012ish

Uh, they do sometimes catch fire while you’re not paying attention? Or were you being sarcastic?

Electric cars or gas cars? Electric cars charge overnight. Improperly balanced packs can overcharge a cell, leading to a fire.

Ford had some fire-related recalls recently[1]. Interestingly one of them was for hybrids, but not due to the battery. It was due to the heat shielding placement and that there was a decent chance of fire in the event of an engine failure from combustible fluids hitting hot parts.

Also I wouldn't say the car being in motion is a convenient time to have a fire. You're often not just standing there with a fire extinguisher handy.

1. https://www.reuters.com/business/autos-transportation/ford-i...

We had a gas-powered bmw self-immolate in the parking garage under one of my buildings at cmu. Made for a slightly exciting afternoon and the most horrible smoke I've ever smelled. Don't think they ever learned why it burned.

Gas cars catch on fire with surprising frequency.

Fuel leaks, electrical shorts, you name it. A lot more frequently than EVs too.

It’s why garages are required to have auto closing fire doors.

I've had multiple ICE cars which have had "don't park in your garage" recalls precisely because they would catch fire overnight while you're sleeping.

Some agency in the UK tested a blanket that contains the combustion, not sure if it puts it out but if your house is protected the EV can be moved.

Youtube search "bridgehill fire blanet"

EVs are being sold all over. Even if this blanket actually works, it needs to be cheap and easy enough to deploy to everywhere with EVs, or become mandatory to include with EV purchases, otherwise it becomes another gimmick nobody can benefit from.

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