Model S Accident/Fire

[cwerdna]

The batteries in the Tesla S are under the floor pan of the vehicle.

So how could the front section which is a trunk catch fire to that extreme?

I had to be something extremely flammable in the trunk that is burning.

I suspect the coolant is flammable and well, there is/are radiator(s) in the front. And, the interior materials within the frunk are likely flammable.

I've had no time to even keep up with more than a few pages of this thread, but so I'm not sure if people have pointed out the emergency response guides at Tesla Motors - Electric Vehicle Safety Training
. Other major automakers put out similar stuff (e.g. see near bottom of https://techinfo.toyota.com/public/main/erg.html).

edit: Nevermind... someone else in the previous page pointed to a page on Tesla's site also w/ERGs.

 

[surfingslovak]

The batteries in the Tesla S are under the floor pan of the vehicle.

So how could the front section which is a trunk catch fire to that extreme?

I had to be something extremely flammable in the trunk that is burning.

Interesting that CHEVROLET ads are on the page with the video ?

Welcome, congrats on the first post. Yes, I was wondering about the same thing too until I saw reports the the pack might have been purposefully venting through the front section of the vehicle in order to protect the passenger cabin. I'm not sure how plausible this is, since I'm not familiar with the internals, but I'm willing to accept this explanation. I would not underestimate lithium fires. Alkali metals are known for their propensity to burn explosively. Batteries don't contain lithium in its pure form, only lithium salts, but some of the volatile nature is likely retained.

 

[Benz]

Is there in the US some kind of a department that has to make sure that the roads are clean, and that there is no debris or any kind of "large metallic objects" lying in the middle of the road?

 

[Mario Kadastik]

Well after the whole fire shenanigans I found myself worried to drive my ICE as unlike a Tesla it's probably just explode if a metal shard hit the fuel tank. Crap. At least I got my VIN for the Model S today, another step closer to a safe car.

 

[Soulopoulos]

Please Calm the Hell Down About the @TeslaMotors Model S Fire by WIRED
http://www.wired.com/autopia/2013/10/tesla-model-s-fire/

 

[brianman]

efforts to discover more about why the crash happened with internal testing (i.e. sacrificing some cars)

A great use for "recycled" (trade-in) 60 kWh vehicles.

 

[Benz]

Although the Tesla Model S is not made to drive over large metallic objects, maybe there should be some kind of additional protection (made of carbon fiber?) under the battery pack? Than this accident will have lead to an even safer Tesla Model S. Now that would be a positive result from this negative story. That would be good news and it would lead to even higher sales figures and an even higher stock price of TSLA. And that's great.

 

[evme]

Welcome, congrats on the first post. Yes, I was wondering about the same thing too until I saw reports the the pack might have been purposefully venting through the front section of the vehicle in order to protect the passenger cabin. I'm not sure how plausible this is, since I'm not familiar with the internals, but I'm willing to accept this explanation. I would not underestimate lithium fires. Alkali metals are known for their propensity to burn explosively. Batteries don't contain lithium in its pure form, only lithium salts, but some of the volatile nature is likely retained.

Lithium Polymer and Lithium Ion are not the same thing.

Is there in the US some kind of a department that has to make sure that the roads are clean, and that there is no debris or any kind of "large metallic objects" lying in the middle of the road?

Not sure, but if there was it will most likely be shut down with the government.

 

[hoopty_yo]

Is there in the US some kind of a department that has to make sure that the roads are clean, and that there is no debris or any kind of "large metallic objects" lying in the middle of the road?

We have giant Roombas that clean the highways; keeping us free of scaffolding and cows that died
from undiagnosed heart conditions that would surely be blocking all lanes of traffic. The local Roomba
was out of service due to an unforseen battery issue caused by a lack of ground clearance.

 

[haid]

Once the accident is understood, enhancing the "ballistic shield" of the battery pack is the most obvious potential fix. An additional approach might be to create a quick-release mechanism for the battery. It would be cool if the car could drop the battery and roll forward 30 feet on the 12 volt battery. This could assist firefighters, protect vehicle occupants, and minimize damage to the main cabin area.

The tricky bits are to make sure that the quick-release mechanism doesn't reduce the structural integrity afforded by the (currently) bolted on battery. How does one make a system that is both well connected to the car and yet easily disconnected when wanted? An engineering challenge, for sure...

This would be a Tesla version of the "eject the core" strategy used in Star Trek.

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How does one make a system that is both well connected to the car and yet easily disconnected when wanted? An engineering challenge, for sure...

This would be a Tesla version of the "eject the core" strategy used in Star Trek.

I suppose the answer to my own question would come from the SpaceX folks. Use "explosive bolts" such as those that enable clean separation of a rocket stage in flight.

 

[CapitalistOppressor]

I would have to back you up. The first point where anyone posted anything that even suggests a battery was involved was here, which came after the post CapOp was referring to:
http://www.teslamotorsclub.com/show...aused-the-fire?p=456259&viewfull=1#post456259
That was right after I jumped in to the discussion and I remember going through the thread before then and no one had any evidence it was the main battery (I asked for it too as did many people before me). The most probable theory seemed to be the 12V one at that point.

I went backwards in the quote chain between you and CapOp and it seems his original theory was the 12V battery.


Then it evolved into the theory of "cascading failure" of the pack which many people disagreed with (as that means the fire spread from module to module based on the technical definition of that term). When asked for evidence, he said it was speculation based on Tesla not making a statement.

This is all just incorrect. I first started talking about a problem with the battery in post #23 in this thread, just 5 minutes after I posted the video. If you look at the post, I was responding to my own post, specifically because I was analyzing the video in real time -

Battery is almost certainly designed to vent to the front of the vehicle. There is no other safe place for it to vent since there might be kids in the rear.

The "liquid" rolling downhill might just be burning asphalt from the intense heat.

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No particularly strong evidence of a crash either. The damage to the front end might just be melted components.

I understand that isn't mentioning a cascade failure. But I was clearly referencing the battery.

Post #47 I posted this (including quotes from the original post for context) -

CO, watching the video, do you think the fire patterns match that venting? Your post seems to hint the main battery actually could be involved here. I was thinking maybe they had regen off and caused a brake fire, but both sides seem to be equally involved from the video.

I should take the advice of government officials who emphasize that we shouldn't immediately blame Al Qaeda for a terrorist attack.

That said, I don't see any evidence that is not consistent with a cascade failure of the main battery, but there are many other possible explanations. My point is that I think folks who are ruling out a battery fire are wrong to do so.

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I thought it might be this at first, but look carefully where the car is sitting - it isn't in the adjacent slow lane yet. In order for this to be a glancing T-bone, the "other" vehicle would had to have traveled into the gore area and the merge lane where the Tesla is sitting to hit it. It doesn't add up. From what I barely can see in between the flames, there does not appear to be major deformation on the driver's side of the car.

I'm calling it a frunk fire, but I'm not an expert.

There isn't any debris from another car. There should be broken glass and brightwork scattered in front of the Tesla if another car was involved.

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I think the debris is completely consistent with melting plastic.

After some more thought, I think the brakes are unlikely. My guess is a 12V short. There was one buyer here that reported that a 12V short on his new Model S that drained the battery, and Tesla had to replace the battery and the defective electronics (A/C, IIRC). That could easily lead to a fire.

A 12v failure is plausible. We have reports of 12v battery deformation.

[/QUOTE]

Any notion that I didn't immediately raise a cascading failure in the pack as a possible cause is wrong. It was the first issue I raised, and I had already discussed the fire patterns, the lack of major impact damage or involvement of other cars and any of a number of other issues very early on in this conversation.

By the time of the Tesla release I was favoring the 12v theory, a) because it was more comforting and I saw no reason to be alarmist, and b) because it made a lot of sense considering that this looked like a spontaneous event, and I've written extensively about how unlikely it is for the Model S pack to spontaneously experience a cascade failure.

Given those factors, and given that I've never actually seen what the flames from a Model S battery fire looks like, the 12v option seemed best.

 

[mitia]

An additional approach might be to create a quick-release mechanism for the battery. It would be cool if the car could drop the battery and roll forward 30 feet on the 12 volt battery. This could assist firefighters, protect vehicle occupants, and minimize damage to the main cabin area.

The tricky bits are to make sure that the quick-release mechanism doesn't reduce the structural integrity afforded by the (currently) bolted on battery. How does one make a system that is both well connected to the car and yet easily disconnected when wanted? An engineering challenge, for sure...

This would be a Tesla version of the "eject the core" strategy used in Star Trek.

I love this idea! I can imagine it's totally impractical for many reasons (like leaving a "bigger on-fire debris" to the cars behind) but however it's a nice thought. Kind of James Bond eject button!

 

[jerry33]

Is there in the US some kind of a department that has to make sure that the roads are clean, and that there is no debris or any kind of "large metallic objects" lying in the middle of the road?

Well, yes there is, but there is still time between when things fall off vehicles and when the cleanup occurs. Depending upon location it could be a week, but even if it's ten minutes that still leaves a window of opportunity for the object to be hit. I can't count the number of objects falling off of trucks--pick-up trucks mainly--that were traveling in front of me. By keeping a decent distance back I've been able to avoid actually hitting the objects but a lot of folks don't keep a decent distance back.

 

[Benz]

We have giant Roombas that clean the highways; keeping us free of scaffolding and cows that died
from undiagnosed heart conditions that would surely be blocking all lanes of traffic. The local Roomba
was out of service due to an unforseen battery issue caused by a lack of ground clearance.

Are you OK?
Should we be worried about your mental health?

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Well, yes there is, but there is still time between when things fall off vehicles and when the cleanup occurs. Depending upon location it could be a week, but even if it's ten minutes that still leaves a window of opportunity for the object to be hit. I can't count the number of objects falling off of trucks--pick-up trucks mainly--that were traveling in front of me. By keeping a decent distance back I've been able to avoid actually hitting the objects but a lot of folks don't keep a decent distance back.

That's exactly what is the main lesson of this accident: "KEEP A DECENT DISTANCE FROM THE VEHICLE IN FRONT OF"

You just need to have enough time to react if something appears in front of you, so that you can slow down and/or drive around it, so that a collision can be avoided at all times.

A clear view of the situation that you are about to enter in the next few seconds should not contain some kind of a surprise for you as a driver.

We need to do something about our driving habits (in general). You don't want anything bad to happen to you, do you?

 

[CapitalistOppressor]

1. Cells vs. modules. I was thinking modules, apparently others are thinking cells. Pretty big difference that explains some of the disagreements in analysis of the evidence.
2. Do we know that it "cascaded to adjacent cells"? Or was it that the object ripped several cells on impact and that, as a group, they "shared a flame"?

I've lost track for #2, hence asking.

I think it must have been more than one cell that was disrupted by the impact. I think the pack is probably more than capable of keeping surrounding cells cool, even if a single cell gets ripped open and vents towards nearby cells. The expected failure mode of the cells (when the pack isn't being speared) is to vent upwards so as to isolate the burning.

But once you get several, or a half dozen speared open, or else knocked out of their channels so that their tops are pointed towards other cells, the combined heatbloom becomes much more dangerous and more likely to start a cascade.

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I've been specifically using the term "cells" in my posts. The Tesla statement mentions one of 16 modules so I'm assuming it was contained within a module.
That's a good point, I've been assuming that all cells which were burning were not necessarily only cells that were impacted initially but that may not be the case. So at this time we can not say for sure that there was a cascade event. I'm guessing there was to some degree, within the damaged module.
See my above response as to why this may not necessarily be the case, though it certainly is likely.

Again, not necessarily. I've seen a number of cell penetration and crush tests where it takes a while for them to start smoking and ignite, and sometimes they never ignite at all.

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Actually it's not a joke, it's a serious issue because of exactly the attitudes you are now running into. That's how people are, and that's what we ran into with the Volt fires and Karma fires, and it didn't go away by not talking about it. That's why we are discussing it, and why locking the thread and pretending it's not an issue is not a rational solution.

One possible non-cascade failure mode that would cause this might be a simultaneous short of the entire module. I'm not sure if that fits the timeline because we would see a lot of energy released more quickly than in a cascade.

Functionally though, the result is the same and I'm not sure I've ever heard a technical term that would describe that.

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I don't agree. IMO the Model S shouldn't have gone to fire for having hit a piece of metal.

Regular cars catch on fire all of the time after hitting pieces of metal. Why the double standard?

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Jalopnik has a story up that includes the transcript of the report (I think that's what it is) which includes the owner's name and home address. Appears he's and orthopedic surgeon in Bellevue.
Batteries Burned In Tesla Model S Fire, Firefighters Say

I think Jalopnik is trying to be nice to Tesla and get out of the doghouse. Their reporting (that I've seen at least) on this has been quite fair.

 

[Bobfitz1]

Has there been any word on recovery of the 'large metallic object' so we have a notion of how large it may have been? Was most of it still on the road or side of road where the impact first occurred? Or was the object smaller and having penetrated into the battery pack, is still there in some charred form? Any word on whether Tesla has recovered the car for analysis? Has the owner posted any comments on what he did or did not see just prior to impact? Sorry if these have already been covered.

 

[CapitalistOppressor]

This confuses me.

After learning that water makes the fire worse, why would they apply water again to the full pack?

Is this an error in the report or are there two different types of fires being battled here?

From what I understand, Tesla actually recommends flooding the pack with large amounts of water to cool it if dry suppressants are not working or not available. The firefighters might have run short of dry suppressants and decided to switch.

Also, I'm not familiar with the chemistry, but one professor type yesterday was mentioning that because this isn't raw lithium it might not react badly with water.

My question from the chemist types would be whether it might be possible for the lithium to have disassociated from the more stable salts and other forms that are actually in the battery thanks to the heat, and then migrated out of the pack as a gas or liquids?

If so, a there might have been purer forms of lithium outside of the pack, which would have reacted with the water, while those inside of the pack were still in more stable (if burning) forms? I know its highly reactive and wont stay "pure" but I'm curious as to how the chemistry might have been working under these conditions.

Also curious as to whether any chemists think that the spark/backfire from the front of the car in the video came from lithium?

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The longer Tesla goes without a formal statement FROM ELON, the worse off it's going to be.

Address it head on (and not in some tiny comments from PR), state that it's being investigated, etc, etc.

The worst thing they can do is just wait.

I understand they need more info, but they don't need anymore info to state that they are looking into it.

Press will keep feeding on it.

This is crisis control 101--face it ASAP.

Yes, I don't understand it. I think they should invite major news organizations out to do a show and tell on Tesla's safety technology and turn this into a positive story instead of just trying to let it all quiet down.

There is increasingly less justification to keeping the innards of the pack secret. Everyone in the world must have dissected it by now, or else will have once Tesla starts selling in China. Open up a pack and show the world how it works to keep people safe and have Elon cite the statistics on car fires for ICE compared to his cars.

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I read a lot of posts here about statistics, that cars DO catch fire from time to time. Tesla is a car. It's therefore a non-event. All is fine.

But what if a Tesla car has 5 times more probability to catch fire than normal car? Still acceptable? Yet maybe not the kind of Tesla standards you are used to.
Would you still prefer driving an EV if this is statistically 5 times less fire proof and yet very safe in all other types of road accidents?

Read this -

http://www.forbes.com/sites/markrogowsky/2013/10/03/yes-teslas-can-catch-fire-but-keeping-cool-is-in-order/

The key quote is this -

Cars catch fire on the highway surprisingly often, 187,500 times in 2011 in fact. There are a bit more than 250 million registered vehicles in the U.S., giving any car approximately a 1 in 1500 chance of being on fire in a given year. By contrast, you’ve only got a 1 in 3000 chance of being struck by lightning in your lifetime, and those odds fall to 1 in 700,000 per year. So this puts the car fire risk in perspective: It’s actually quite high. Yet, with around 20,000 Teslas on the road, this is apparently the first such incident of one catching fire. Given that the Model S is new, that isn’t shocking. It’s more likely an older car will catch fire than a recent model. But it seems so far, it’s also far more likely a gas-powered vehicle will catch fire than an electric — leaking gasoline is more combustible.

 

[texex91]

Well another day of speculation posts here...I'm hoping to see fewer and fewer posts in this thread.

And the sooner it drops to the bottom of the page the better.

Let's get back to enjoying our Tesla's and telling people how great they are, instead of having to defend why we own one.

PANIC is over folks...stock up $2.10 in after hours! Let's get back to life...sorry shorters.

 

[artsci]

Well another day of speculation posts here...I'm hoping to see fewer and fewer posts in this thread.

And the sooner it drops to the bottom of the page the better.

Let's get back to enjoying our Tesla's and telling people how great they are, instead of having to defend why we own one.

PANIC is over folks...stock up $2.10 in after hours! Let's get back to life...sorry shorters.

.
Amen. This all amounts to much ado about absolutely nothing.

 

[CapitalistOppressor]

Yeah, this worries me too. Although I'm not 100% on the details from what I've read the Tesla hit a "metal object" which caused the fire.

Will fender benders be a serious problem for Tesla? If simply hitting a metal object caused a fire then surely a fender bender would cause the same damage, right?

Well time will tell but this fire does have me a little concerned.

Whats the plausible mechanism for a "fender bender" to cause a pack fire? Unless the Model S lands on top of your car as a result, how do you replicate these conditions?


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So, it appears that some of the articles (or reader comments on them), as well as some of the folks on this thread have made the claim, or pointed to Tesla's patents regarding, "intumescent goo" within the battery pack. It's essentially a flame retardant, in that it's a substance that expands and chars with heat, thus absorbing substantial energy in order to reduce thermal runaway leading to cascading failures.

I first heard of it on CO's threads discussing the battery pack design. Tesla's patents seem to describe using it in battery pack construction, and there were some early battery pack designs that appeared to have used it, if memory serves. However, in those threads I believe the conclusion was that the final pack didn't seem to have any evidence of it being included.

I wonder if we have any definitive final answer on that (CO ?). I also wonder if it, or it's absence, would have been a factor in an event as significant as this one turned out to be?

We know its not included on the Rav4 cells.

I thought the stuff was neat, but maybe they determined that it causes more problems than it solves. They have a ton of battery patents, for a variety of components, that describe using intumescent coatings or materials. But I've yet to have anyone confirm their use.

In the mean time, I'm assuming they are not present.