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First Responders Unprepared for Electric Vehicle Fires: Report

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Re: First Responders Unprepared for Electric Vehicle Fires: Report

#31

Post by clouddrover »

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…

> emergency crews can spray water on the battery

Here's what happens when you spray water on the battery:

https://www.thedrive.com/news/36212/reminder-electric-cars-c...

> every battery cell could have a built in discharge circuit

A better idea is solid state batteries. They can be damaged without catching on fire:

https://www.youtube.com/watch?v=m9-cNNYb1Ik

https://www.youtube.com/watch?v=ZOubFHO1I3o

And explosive fuses can be used to disconnect the battery automatically after a crash:

https://www.cnet.com/roadshow/news/bosch-electric-car-explos...

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#32

Post by foobar1962 »

I was a flag marshall at a race track a year or so ago, one of the classes racing was the Radical, a lightweight mini LeMans car based on a hight performance motor cycle engine. They are pretty awesome. One car was a full battery EV which they were testing out. We were instructed that if it crashed and caught fire were were NOT to assist ourself but to wait for the main team to arrive.

As an aside, the eRadical was some 300kg heavier than the ICE version but otherwise identical. As for competition: there wasn't any. From the flag drop at the start the eRadical jumped ahead (thanks to electric engines offering 100% torque at 0 rpm) and held that lead throughout the race. The only time it didn't;t finish first was the last race of the day which was double length: it DNF due to exhausted battery.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#33

Post by IgorPartola »

Tesla had a really good set of videos on how to respond to emergencies involving electric vehicles. They obviously showed it on a Tesla but I thought it was really well made in that they talked about other designs and what will be in common and what won’t. I am not a first responder so there is little direct reason for me to know this but I spent several hours watching the videos anyways simply because they were so interesting and so well made.

Similarly, I really liked the video from an ER doctor who races motorcycles about responding to motorcycle crashes. Highly recommend learning more about this as you very well might be the first person there and the dangers are non-obvious. And of course I highly recommend taking a CPR course and carrying a first aid kit, including a mouth to mouth membrane, with you in your vehicle. You never know when you’ll be in a position to save a life.

Edit: Tesla emergency responder resources: https://www.tesla.com/firstresponders

Motorcycle crash response: https://youtu.be/MsZBXlTHPCg

Red Cross CPR certification: https://www.redcross.org/take-a-class/cpr/cpr-training/cpr-c...

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#34

Post by kube-system »

gumby wrote: post #28

I’m surprised as I read when the Prius was introduced that they’d done an educational campaign specifically about this (both battery fires and how to cut the car open without electrocuting yourself). I’d assumed this was a regulatory requirement.

Some states do not require any mandatory training for volunteer firefighters.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#35

Post by HPsquared »

imglorp wrote: post #29
dreamcompiler wrote: post #18

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…

Unscheduled airbag deployment is a terrifying concept if you're trying to lean in to access a person. Why do military aircraft have RESCUE --> levers that disarm all the pyros but we can't make that a thing on cars? It wouldn't have to be a big red sign but it could be a standard.

Probably budget, and ejection seats are a bit more dramatic than airbags.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#36

Post by Reason077 »

imglorp wrote: post #29
dreamcompiler wrote: post #18

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…

Unscheduled airbag deployment is a terrifying concept if you're trying to lean in to access a person. Why do military aircraft have RESCUE --> levers that disarm all the pyros but we can't make that a thing on cars? It wouldn't have to be a big red sign but it could be a standard.

> "Why do military aircraft have RESCUE --> levers that disarm all the pyros but we can't make that a thing on cars?"

Not sure if it's standard on all EVs, but cutting the first responder loop on a Tesla will disarm the airbags & SRS, in addition to disconnecting the high voltage system.

Source: Tesla first responder guide: https://www.nfpa.org/-/media/Files/Training/AFV/Emergency-Re...

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#37

Post by function_seven »

xxpor wrote: post #27
LatteLazy wrote: post #20

Earlier quoted context omitted.

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?

Superchargers charge at 480V max, which from my understanding go directly into the cells (there's two phases in lithium battery charging, constant current and constant voltage. I'm fairly certain the constant voltage is for when the battery is low) So technically not "high voltage" as defined by the NEC (that starts at 600V), but still plenty enough to kill you. Especially if you're wet.

> (...I'm fairly certain the constant voltage is for when the battery is low)

Backwards. When the cell is low, the charging is at a constant current. The current is limited to whatever is deemed safe for the battery.

Once the battery has charged to 80% or so, then the voltage will have reached the top, and any attempt to maintain the current will over-volt the cells. So the current is allowed to taper off as the voltage is held constant.

For a single cell, that means the charger will apply whatever voltage is needed to deliver, say, 1 amp. Then when the voltage hits the 4.2V ceiling, it will stay there as the current naturally decays. A 100% charge is declared when the current falls below some threshold, like 50mA.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#38

Post by [deleted] »

FireBeyond wrote: post #21
dreamcompiler wrote: post #18

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…

> Our department has trained on hybrids (don't cut the big orange cable!) Keep training up to date. Hybrid HV wiring has a conductive sheath around the actual wiring, separated by non conductive layers. The purpose of this is that when your tool cuts such wiring, it shorts the sheath first and trips a breaker, so that you should be able to cut. There's a group near here (WA state) that does demos including "throwing"…

[deleted]

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#39

Post by kiddico »

IgorPartola wrote: post #33

Tesla had a really good set of videos on how to respond to emergencies involving electric vehicles. They obviously showed it on a Tesla but I thought it was really well made in that they talked about other designs and what will be in common and what won’t. I am not a first responder so there is little direct reason for me to know this but I spent several hours watching the videos anyways simply because they were so i…

The guy in the motorcycle video is just an all around fun presenter! Good recommendation.

edit: Seems as though Dr. Hinds is no longer with us. Accident while providing medical care at an event. Damn. Gotta say that's a commendable and badass way to go.

Re: First Responders Unprepared for Electric Vehicle Fires: Report

#40

Post by [deleted] »

kube-system wrote: post #24
mpalczewski wrote: post #16

Earlier quoted context omitted.

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…

Of course. I am under no impression that tort lawyers are either experts in, or interested in, chemical engineering or firefighting practices. Their expertise is in illustrating culpability for civil wrongs. The author is simply establishing that the situation is dangerous and has inherent differences that would necessitate different training. The actual differences in combustion byproducts are 100% irrelevant to the…

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