First Responders Unprepared for Electric Vehicle Fires: Report • Hacker News Board

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#11

Post by LeifCarrotson » Mon, Nov 23, 2020, 10:18 PM UTC

londons_explore wrote: post #7

bleepblorp wrote: post #6

Earlier quoted context omitted.

You'll make a fortune if you can find a way to convert 40-150 KWhr of electrical energy to heat quickly enough to make a difference in an emergency situation without causing the car to combust (or explode). You'll make a fortune because you'll have broken the laws of physics.

A big firehouse is 184 Megawatts of cooling (assuming it is all vaporised). That will empty your battery in literally 2 seconds if you can direct it well enough... No breaking physics laws necessary.

I did a tour of an 80 MW coal power plant during my electrical engineering coursework. You're not going to fit an 184 MW heat exchanger in the garage the car gets parked in, much less the battery pack under the floor.

Also, as the article suggests, carbon monoxide is bad, and obviously you need oxygen to breathe, but firefighters have equipment that can help with that. However, when you've directed all the energy in the battery into a couple hundred pounds of water, the resulting 100C steam will instantly give 3rd degree burns to anyone in the airspace within a 10m cube around the vehicle.

Vehicles hold a shocking amount of energy to be able to transport thousands of pounds of steel for hundreds of miles. Because burning gasoline is a visceral experience, no one suggests that at arrival to an ICE car you should vaporize and exploding 20 gallons of fuel. Instead, you must prevent the fuel from burning.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#12

Post by kube-system » Mon, Nov 23, 2020, 10:20 PM UTC

quercusa wrote: post #4

> The U.S. National Transportation Safety Board (NTSB) recently issued a report showing that many fire departments lack the training and equipment needed to properly handle burning lithium-ion batteries. That survey was published in 2018 ('recently'), so probably collected in 2017. My son is a volunteer firefighter and he reports that they have had no shortage of training on EVs. And that they don't do anything witho…

The article does say that 31% of those surveyed didn't have the training, so presumably, the majority of departments do have the training. Given the number of poor rural volunteer departments in the US that struggle with funding, I would assume that 31% probably overlaps with the set that are struggling in general.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#13

Post by gowld » Mon, Nov 23, 2020, 10:28 PM UTC

kube-system wrote: post #12

quercusa wrote: post #4

> The U.S. National Transportation Safety Board (NTSB) recently issued a report showing that many fire departments lack the training and equipment needed to properly handle burning lithium-ion batteries. That survey was published in 2018 ('recently'), so probably collected in 2017. My son is a volunteer firefighter and he reports that they have had no shortage of training on EVs. And that they don't do anything witho…

The article does say that 31% of those surveyed didn't have the training, so presumably, the majority of departments do have the training. Given the number of poor rural volunteer departments in the US that struggle with funding, I would assume that 31% probably overlaps with the set that are struggling in general.

Also raises the question of what share of EVs are in poor rural jurisdictions. EVs are more popular in urban areas that have charging infrastructure and shorter-range trips.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#14

Post by bigbubba » Mon, Nov 23, 2020, 10:29 PM UTC

kube-system wrote: post #3

colechristensen wrote: post #2

Quoting carbon monoxide as of it were a unique product of a battery fire immediately casts doubt as to any of this being a legitimate concern. Getting something so wrong ruins the credabity of the rest of the piece. (every fire involving carbon produces some CO especially when oxygen is limited and combustion becomes less and less complete)

It's an article by a tort lawyer who is commenting on the lack of training. It is not a engineering analysis -- in context, it is clear that those chemicals were simply listed as examples.

Carbon monoxide is presented as an example of a "Unique danger[s] associated with electric battery fires." Why should he get a pass for being a lawyer? That makes his ignorance more concerning, not less.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#15

Post by gowld » Mon, Nov 23, 2020, 10:31 PM UTC

londons_explore wrote: post #5

The issue of EV batteries reigniting after a crash seems very solvable... For example, every battery cell could have a built in discharge circuit. Whenever the cell no longer received a signal from the cars computer indicating "the car is healthy" it goes into failsafe mode. Failsafe mode consists of every cell discharging to zero volts through a PTC resistor to keep a constant temperature of 150 degrees C. That will…

Intentionally closing a circuit after a crash, where water is likely to be added seems risky, akin to creating a downed power line next to a creek.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#16

Post by mpalczewski » Mon, Nov 23, 2020, 10:32 PM UTC

kube-system wrote: post #3

colechristensen wrote: post #2

Quoting carbon monoxide as of it were a unique product of a battery fire immediately casts doubt as to any of this being a legitimate concern. Getting something so wrong ruins the credabity of the rest of the piece. (every fire involving carbon produces some CO especially when oxygen is limited and combustion becomes less and less complete)

It's an article by a tort lawyer who is commenting on the lack of training. It is not a engineering analysis -- in context, it is clear that those chemicals were simply listed as examples.

From the article

"Unique Dangers Associated with Electric Battery Fires First, during an electric vehicle fire, over 100 organic chemicals are generated, including toxic gases like carbon monoxide and hydrogen cyanide, both of which are fatal to humans."

It's propaganda. "primarily to influence an audience and further an agenda" You aren't getting any facts in there that don't further the authors claims, and the ones that are there are written in a dishonest way.

If the author said that "during an electric vehicle fire, over 100 organic chemicals are generated as opposed a conventional vehicle fire where 10/100/1000 different organic chemicals are generated" at least you'd have a basis of comparison, as it is, it just written to sound scary without informing you in any way what so ever.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#17

Post by almost_usual » Mon, Nov 23, 2020, 10:33 PM UTC

gowld wrote: post #13

kube-system wrote: post #12

Earlier quoted context omitted.

The article does say that 31% of those surveyed didn't have the training, so presumably, the majority of departments do have the training. Given the number of poor rural volunteer departments in the US that struggle with funding, I would assume that 31% probably overlaps with the set that are struggling in general.

Also raises the question of what share of EVs are in poor rural jurisdictions. EVs are more popular in urban areas that have charging infrastructure and shorter-range trips.

I see EVs in rural California all the time. If an EV gets into an accident on its way to a national park the closest fire department is going to respond.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#18

Post by dreamcompiler » Mon, Nov 23, 2020, 10:52 PM UTC

Firefighter/EMT here. Our department has trained on hybrids (don't cut the big orange cable!)[0] but not electric per se. Doesn't matter. Unless there's someone in the car, we're going to stand back, let it burn, and keep it from spreading.

Cars contain bigger hazards than batteries: Airbags are basically bombs, and gas lifters (the things that make the hatchback open smoothly) can become missles in a fire. And that bit about cyanide? Ha! When your sofa catches on fire it releases cyanide. That's why we wear positive pressure SCBAs.

[0] We typically cut battery cables on conventional cars to lessen the danger of an airbag exploding in our face during a rescue.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#19

Post by exabrial » Mon, Nov 23, 2020, 10:54 PM UTC

One of my firefighter friends says they're a little fearful of using the jaws of life on electric vehicles since cutting through a high-voltage electrical cable would be disastrous. Luckily there are so few models right now they can memorize no-go places, but obviously this can't be counted on forever.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#20

Post by LatteLazy » Mon, Nov 23, 2020, 11:00 PM UTC

exabrial wrote: post #19

One of my firefighter friends says they're a little fearful of using the jaws of life on electric vehicles since cutting through a high-voltage electrical cable would be disastrous. Luckily there are so few models right now they can memorize no-go places, but obviously this can't be counted on forever.

Edit: Cell voltage in a tesla is only 4.1V max. But there are systems with up to 375 total so I guess it's a valid question, especially as company's (not tesla AFAIK?) start putting cells into the body to squeeze as many as possible in...

Original question:

Isn't it all low voltage?