Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Extinguishing the EV Battery Fire Hype

spectrum.ieee.org

Post reply on HN
Print view View original

31–40 of 72 posts

Re: Extinguishing the EV Battery Fire Hype

#31

Post by dataflow »

vel0city wrote: post #30
dataflow wrote: post #27

Earlier quoted context omitted.

Fascinating, thanks. > the anti-lock brake control module can leak fluid and cause an electrical short, which can touch off a fire while the vehicles are parked or being driven. > [...] Dealers will replace the anti-lock brake fuse at no cost to owners. How can replacing a "fuse" prevent fluid leakage?!

Sizing the fuse to be smaller means the fuse will blow faster at the short before the wires in the puddle of brake fluid get hot enough to start the fire. Chances are the fuze was oversized to begin with.

I figured about as much, but I guess my point was: shouldn't they be fixing the leak?! Would people even know about the leak otherwise? Or is this going to silently surprise/kill people when their ABS fails?

Re: Extinguishing the EV Battery Fire Hype

#32

Post by pid-1 »

fragmede wrote: post #21
sanderjd wrote: post #13

Earlier quoted context omitted.

> But I think it is much less likely to occur You think . The point of gathering data and studying it is to attempt to replace our animal-brain intuitions with real evidence. I honestly haven't looked into the evidence on this enough either way, since I haven't yet seriously researched purchasing an electric vehicle. But I know that I have a big tank of gasoline sitting directly underneath a portion of my childrens'…

It's worse than that! You (well, I'm guessing, I don't actually know you) have this wire just bringing foreign ideas, and crazy people's written thoughts, from all over the world, and you pipe them straight into your brain, with no helmet on. And this happens right next to your kids! You're a mad man!

Are you worried about wires? Wait until I tell you about invisible electromagnetic radiation.

Re: Extinguishing the EV Battery Fire Hype

#33

Post by vel0city »

dataflow wrote: post #29
XorNot wrote: post #26

Earlier quoted context omitted.

There's an entire 12V electrical system which stays active. There's also rubber and plastic parts, possible contaminants, a bevy of additives...plenty of interesting chemistry which normally does nothing but in the right sequence of unlikely events leads to an ignition.

> There's an entire 12V electrical system which stays active. [...] I'm not that illiterate about cars or basic physics. I was trying to figure out what actually went wrong in their situation. Because I'd never heard of any specific cases of these actually happening. Previously these sounded incredibly less likely to me than what I'm now discovering here.

I don't remember the specifics about that situation. Something melted and slowly leaked and eventually caught fire. I don't think whatever happened in that case rose to become a recall. It was a relatively new Cadillac in the mid 1990s IIRC. I was a kid at the time it happened.

But yeah, vehicle fires happen to parked cars all the time. As mentioned I've had multiple cars have "don't park in the garage" kind of recalls, one car has even had multiple (Hyundai). In the article posted above it opens with:

> WHILE SOME FIRES in motor vehicles occur as a result of collisions, most occur in motor vehicles not involved in collisions. These non-crash-induced fires are relatively frequent (one for every 1,000 registered vehicles) but in general are less hazardous to occupants and bystanders than crash induced fires.

It later states:

> They occur on an average of one out of every 1,000 registered vehicles and can result in significant property damage

https://www.jstor.org/stable/44631649

Re: Extinguishing the EV Battery Fire Hype

#34

Post by api »

bob1029 wrote: post #8

You'll never catch me with a lithium ion battery larger than ~150wH inside my home. I don't care how aggressively the statistics are massaged. I've personally experienced laptop and cellphone batteries catching on fire and can see how something with 100x+ the capacity could cause some serious fucking trouble. Anyone who has one of those 1kWh+ emergency power backup things sitting inside their house right now really n…

Gas cars spontaneously igniting are rare, but flammable liquids like solvents or gasoline for lawn equipment catching fire and causing massive destruction is fairly common. People often do things like store solvents in basements where fumes can get loose and get near furnaces and other equipment and ignite.

Stored energy is stored energy.

You do have a bit of a point about large lithium power bricks. I trust those things less than I trust an EV, especially if they are the weird ChinaCorp off brand type from Amazon.

Re: Extinguishing the EV Battery Fire Hype

#35

Post by dataflow »

vel0city wrote: post #33
dataflow wrote: post #29

Earlier quoted context omitted.

> There's an entire 12V electrical system which stays active. [...] I'm not that illiterate about cars or basic physics. I was trying to figure out what actually went wrong in their situation. Because I'd never heard of any specific cases of these actually happening. Previously these sounded incredibly less likely to me than what I'm now discovering here.

I don't remember the specifics about that situation. Something melted and slowly leaked and eventually caught fire. I don't think whatever happened in that case rose to become a recall. It was a relatively new Cadillac in the mid 1990s IIRC. I was a kid at the time it happened. But yeah, vehicle fires happen to parked cars all the time. As mentioned I've had multiple cars have "don't park in the garage" kind of recal…

Thanks!

Re: Extinguishing the EV Battery Fire Hype

#36

Post by vel0city »

dataflow wrote: post #31
vel0city wrote: post #30

Earlier quoted context omitted.

Sizing the fuse to be smaller means the fuse will blow faster at the short before the wires in the puddle of brake fluid get hot enough to start the fire. Chances are the fuze was oversized to begin with.

I figured about as much, but I guess my point was: shouldn't they be fixing the leak?! Would people even know about the leak otherwise? Or is this going to silently surprise/kill people when their ABS fails?

The fuse swap is a temporary fix to make the cars safer until a full fix can be rolled out. I imagine truly "fixing" the leak means redesigning the ABS module, something that takes time. They need to investigate what makes the leak happen, redesign the actual part, validate that new part doesn't have some other issue, call the new part out for manufacturing (and make millions of them), get them in the hands of dealers, and then actually start replacing the part.

In the mean time, swap the fuze, and while the car is going to become immobilized or throw ABS warnings when the leak happens its not going to burn someone's house down.

Re: Extinguishing the EV Battery Fire Hype

#37

Post by dataflow »

vel0city wrote: post #36
dataflow wrote: post #31

Earlier quoted context omitted.

I figured about as much, but I guess my point was: shouldn't they be fixing the leak?! Would people even know about the leak otherwise? Or is this going to silently surprise/kill people when their ABS fails?

The fuse swap is a temporary fix to make the cars safer until a full fix can be rolled out. I imagine truly "fixing" the leak means redesigning the ABS module, something that takes time. They need to investigate what makes the leak happen, redesign the actual part, validate that new part doesn't have some other issue, call the new part out for manufacturing (and make millions of them), get them in the hands of dealer…

It didn't sound like they were planning to do more than this, but I admittedly stopped reading the article fairly quickly after this part. I guess others pointed out the same thing so hopefully they'll have to follow up.

Re: Extinguishing the EV Battery Fire Hype

#38

Post by verisimi »

_ea1k wrote: post #10
dpedu wrote: post #5

> [Firefighters have] had 100 years to train and to understand how to deal with internal combustion engine fires,” the NFPA’s Andrew Klock told Vox. “With electric vehicles, they don’t have as much training and knowledge.” > But MSB’s Per-Ola Malmqvist has developed webinars that explain how to safely put out battery fires. In a 2022 webinar, he described the tools and techniques that were used to put out a raging EV…

Sure, but that seems like mostly a question of getting them to a place where that can safely happen. Once it is isolated, let it burn out if it reignites. Putting it out the first time so that it can be safely moved is important.

> Once it is isolated, let it burn out if it reignites.

Mere words do not quite convey the issue.

How does one "isolate" a car? Does one take it somewhere? Where? Are fire engines able to undertake this task? It's there a concern en route to the somewhere?

Re: Extinguishing the EV Battery Fire Hype

#39

Post by Qwertious »

api wrote: post #34
bob1029 wrote: post #8

You'll never catch me with a lithium ion battery larger than ~150wH inside my home. I don't care how aggressively the statistics are massaged. I've personally experienced laptop and cellphone batteries catching on fire and can see how something with 100x+ the capacity could cause some serious fucking trouble. Anyone who has one of those 1kWh+ emergency power backup things sitting inside their house right now really n…

Gas cars spontaneously igniting are rare, but flammable liquids like solvents or gasoline for lawn equipment catching fire and causing massive destruction is fairly common. People often do things like store solvents in basements where fumes can get loose and get near furnaces and other equipment and ignite. Stored energy is stored energy. You do have a bit of a point about large lithium power bricks. I trust those th…

>Stored energy is stored energy.

There's plenty of stored energy in a slab of solid steel, but that doesn't make it remotely dangerous. What makes lithium-batteries dangerous is the thermal runaway, enabled by the liquid capacitor.

Re: Extinguishing the EV Battery Fire Hype

#40

Post by marcosdumay »

vel0city wrote: post #7
derbOac wrote: post #6

My impression is that the concern with EV and battery fires is that they can occur in the home or while otherwise stationary, unexpectedly causing much more catastrophic damage. ICE fires, in contrast, seem to be mostly associated with collisions, or somewhat less so with driving; it seems uncommon for ICEs to suddenly catch fire in an enclosed building. e.g., https://www.jstor.org/stable/44631649 I'm not an expert o…

ICE fires aren't often related to collisions. I've seen a neighbor's house burn down due to a car that had been parked in their garage for hours combusting. I've had multiple ICE cars recalled for catching fire when stopped. In the examples in the articles they mentioned vehicles in parking garages and on cargo ships, those weren't moving. Your general impressions don't reflect reality. Out of all the cars I've owned…

To be fair, ICEs tend to cath fire while they are moving. That's the time every system in the car is most stressed.

That means the odds of it catching fire on your garage while you sleep are lower.

EVs by their turn are highly stressed while charging.

Post reply on HN