Model S Accident/Fire

[CapitalistOppressor]

I agree with this completely. I don't think of 'colliding' as the same as 'running over'. I guess its a collision in some ways, but would be a very odd choice of words.

I also agree I this hypothesis.

I still have difficulty envisioning a collision with a piece of metal being able to affect anything inside of the frunk without being a major impact. The 12v battery or anything else in the frunk is much less exposed to damage than the main battery unless the impact is above the bumper, or the thing you are hitting is quite massive.

 

[markrogo]

If anyone has crashed their Tesla and would be willing to chat very briefly for a post on my Forbes blog, please shoot me an e-mail: forbes at rogo dot net... If you leave a number, I'll call you as soon as I see the mail.

I don't want to make a big case out of this, but rather am doing a post on "yes, cars crash, yes, people are scared when they are electric cars, but reality indicates..." It will be the opposite of a hit piece if anyone is concerned with how these things are normally covered.

 

[rolosrevenge]

Tesla said that the collision caused significant damage to the vehicle. Ripping into the pack fits that description.

 

[Norse]

Because they don't have data to support that assertion, yet.

"OMG OMG OMG Tesla must respond immediately."
Tesla responds.
"Tesla didn't say enough therefore..."
Tesla responds more, with incomplete data, and overstates things.
"Tesla proven to be wrong, film at 11."

Calm down and stop jumping to conclusions based on things not said.

Jeepers creepers.

I guess you refer to me regarding that Tesla should respond fast. When I said that the stock traded at 185$. When they came with their statement the stock traded at 175$. So yes, im pretty glad they did

 

[NigelM]

I still have difficulty envisioning a collision with a piece of metal being able to affect anything inside of the frunk without being a major impact.

Tesla said "a large metallic object" which to me is something very different to a "piece of metal". As I speculated up-thread, maybe the large metallic object was a gas cannister? Could have been many different things.....

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Tesla said that the collision caused significant damage to the vehicle. Ripping into the pack fits that description.

But the car continued to function as it was designed and the driver was able to pull over safely.....kinda suggests that nothing "ripped into the pack"

 

[kevin99]

Tesla said "a large metallic object" which to me is something very different to a "piece of metal". As I speculated up-thread, maybe the large metallic object was a gas cannister? Could have been many different things.....

I didn't think you were serious about the gas canister large metallic object!

 

[Discoducky]

So the video is very helpful in that it appears that:

1. The police have yet to arrive on the scene. I find that strange as the closest fire station is 3.1 miles away and would expect that the driver called 911. In the video you get a glimpse of the drivers side mirror and there are no flashing lights from a police car.
2. There is no ambulance on site. Also strange for an auto accident.
3. Where is the driver? You'd think the driver would be by a vehicle
4. Also, notice how far away the cars are up on the off-ramp. Who/what is stopping them from driving down? You'd think there would be a policeman there, but maybe the firemen stopped the cars.
5. The windows of the S are fogged up which indicates there is still moisture in the air inside the cabin indicating that the cabin is still in tact (all windows are sealed and no other intrusions)
6. The car looks like it came to a rest as opposed to stopping at the intersection. The final spot of the car does NOT look intentional or ideal.
7. The handles are not extended which leads me to believe that the car might not have been put in Park or the 12V was still in tact for a few minutes after the driver got out and closed the door
8. The intensity of the fire would indicate combustible liquid being the accelerate which could be the 12V, however, the fire is evenly spread and is also going underneath the car (under the front doors)
9. The suspension looks way low and might be the result of the air suspension loosing power and could indicate 12V loss but not as a cause, more of an effect

Ok, that's all I got...

 

[ToddRLockwood]

Maybe the owner was carrying gas for the lawn mower in the frunk.

I was thinking the same thing. From the side view (in the video) the fire seems confined to the front third of the car—not where the battery pack is located. The hood damage could be entirely due to the jaws-of-life, not an impact.

 

[omarsultan]

Tesla said that the collision caused significant damage to the vehicle. Ripping into the pack fits that description.

Yes, but so would being stepped on by an errant T-Rex, and there are roughly an equal number of facts to support either theory.

O

 

[brianman]

There is an update on the jalopnik article:

Yesterday, a Model S collided with a large metallic object in the middle of the road, causing significant damage to the vehicle. The car’s alert system signaled a problem and instructed the driver to pull over safely, which he did. No one was injured, and the sole occupant had sufficient time to exit the vehicle safely and call the authorities. Subsequently, a fire caused by the substantial damage sustained during the collision was contained to the front of the vehicle thanks to the design and construction of the vehicle and battery pack. All indications are that the fire never entered the interior cabin of the car. It was extinguished on-site by the fire department.

My attention is drawn to the (now) underlined portion.

GasDoc, if you're around, is this a different user experience than when your vehicle underwent its drama? If yes, do you think this was related to your suggestion at Teslive?

 

[NigelM]

I didn't think you were serious about the gas canister large metallic object!

It could have been any number of things; I was just making the point that a gas canister fit the description as well as anything else.

 

[omarsultan]

However, I think it's highly likely they have a good idea what happened. You don't even need a lot of time: 1. interview driver 2. examine bottom of pack 3. draw conclusion.

If I were Tesla, I would actually want to open up the battery pack and ensure it was pristine before getting any more definitive--nothing sucks more with corporate communications then having to walk something back. Plus, if that is the case, its a hell of a talking point--even with the front of the car on fire, the battery is still untouched.

 

[rolosrevenge]

But the car continued to function as it was designed and the driver was able to pull over safely.....kinda suggests that nothing "ripped into the pack"

Continuing to function as designed in the case of a large metallic object breaching the front of the pack would be to: warn the driver, isolate the breached cells, let the driver use the rest of the pack to pull over to the side and get out, and containing the fire to only the breached cells instead of having them spread.

 

[CapitalistOppressor]

+1

I am just blown away by the rampant speculation and statements made "with high certainty" with no access to the actual facts...

WTF?? Ok, lets see now, I appear to be the main protagonist to this story since I am the one who has consistently put forward the possibility of a pack fire. Here are ALL of my posts on the subject, with notes appended in red -

Looks like (where is the high level of certainty?) we have an answer. Appears to (not here) be a pack fire (though its not stated as such, Tesla would have specifically denied it if it was not IMHO (or here)) caused by an impact with debris.

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If it was enough to rip through the floor pan, it would cause a short and a fire. Then the pack safety systems would vent the heat towards the front.

(looks to me like I am clearly stating only a possible hypothesis)

The pack is not designed to have a large metallic object rip through it either. I agree, more than one cell would have needed to combust to cause a cascade.

That said, if this was not a battery fire, then the Tesla statement was PR malpractice. They must know that a battery fire is the primary concern, and if this was not a battery fire they should have specifically denied it.

Given that we have a cause (metallic debris) and a plausible effect (not a certain effect) (a cascading failure from a pack that was ripped open), I'll take that and run with my speculation in the absence of a statement by Tesla otherwise.

(again, I admit this is opinion and speculation. Where do I indicate certainty? Let alone a "high level" of certainty?)

What is your other plausible source? The 12v battery is less vulnerable to this type of damage than the main pack. (clearly I am engaging in debate)

A random gas can is even more isolated, and they aren't easy to break in any case. I suppose it could be thrown against the front of the frunk and blow the lid off, which would spray the interior of the frunk. Where is your evidence that there was an impact hard enough to do that? The car rolled onto a transition and stopped, it didn't get stopped by an impact. And even if it did, you then need an ignition source. (I've remained open to other possibilities from the beginning, while expressing skepticism over their likelyhood)

In contrast, a piece of every day metallic debris, like that which rips open oil pans and gas tanks every day, could readily rip through the bottom of the battery, not stop the car, and cause a short that would cascade though the pack.

And again, Tesla did not deny a battery fire. Why in the world would an EV company, which faces intense scrutiny over the possibility of a battery fire, not immediately deny that this fire came from the pack?

By "ripped open" I mean breached. Though technically, just a substantial dent could be enough to cause this. Anything that is enough to displace the cells and cause a short could cause a cascade.

Yes, it's possible it didn't cascade through the entire pack. Some of the designs listed in the patents show various partitioning schemes which could isolate it to just the front section of the battery.

(again, where is the certainty?)

Cascading combustion of lithium ion cells is an inherent danger in any large pack. Tesla wouldn't have taken time to file a dozen patents on how to prevent or mitigate it if it wasn't. That doesn't mean that a protection system can't be defeated by a catastrophic impact with a metal object. I don't see why folks would find this objectionable.

Look, I'll allow that there are still a number of other plausible causes that don't seem as probable to me. I didn't mean to imply that there was any kind of 100% certainty that the pack caught fire. (in fact, looking at the record, I never did imply any such thing. What was it someone said? "Learn to read")

It just seems like the most likely option given what I personally know (Most Likely != "High level of certainty")), and my brain is wired to rapidly solve complex problems based on limited information. I get paid a lot of money to do that, but I'll be the first to admit that I can be, and often am wrong. I didn't intend to make folks think I was trying to shut down debate.

Ok, the coolant lines breaking is an interesting twist I hadn't thought of. Quite plausible, and perhaps easier to accomplish than breaching the pack. Same with the radiators. That still leads us to a cascade though (in this case caused by lack of cooling), or else we wouldn't have had the fire.

Have you seen the interior of the pack? Tesla has a number of patents showing various partitioning schemes, and if I recall the most robust would still leave ~48 cells exposed to each other. I'm not sure if 48 could give the energy needed to blow off the burst panels and cause a fire like this. Some of the designs had more batteries exposed though. A whole sheet of 96 maybe?

(again, where is this "high level of certainty"?)

 

[dsm363]

Well 'it just seems like the most likely option given what I personally know' does indicate at least a moderate level of certainty to me at least. We basically don't know and there certainly isn't any good evidence this was a pack fire at the moment but no definitive proof it wasn't either.

 

[NigelM]

Continuing to function as designed in the case of a large metallic object breaching the front of the pack would be to: warn the driver, isolate the breached cells, let the driver use the rest of the pack to pull over to the side and get out, and containing the fire to only the breached cells instead of having them spread.

Ok, now we're in fantasyland. It was confirmed that the car "collided with a large metallic object"; it wasn't confirmed that the car ran over something small enough to go under the car and still be strong enough to rip through the 1/4" steel battery pack which despite losing cells and coolant all over the road continued to operate till the driver could pull over.[/sarcasm. I apologize]

There's any number of things which could have happened so please let's stop insisting that something "ripped into the battery pack" when there is zero evidence to that.

 

[omarsultan]

Wasn't it Rumsfeld who talked about known and unknown unknowns?

 

[AmpedRealtor]

I see absolutely no evidence of a "pack fire" from any of the videos, photos or news reports. Suggesting as much would be quite premature, especially when those who are suggesting such a thing know next to nothing about the battery design other than what they've read online and through other people's speculations.

 

[Zzzz...]

Have you seen the interior of the pack? Tesla has a number of patents showing various partitioning schemes, and if I recall the most robust would still leave ~48 cells exposed to each other. I'm not sure if 48 could give the energy needed to blow off the burst panels and cause a fire like this. Some of the designs had more batteries exposed though. A whole sheet of 96 maybe?

Yes, you could see interior of the pack in the "Battery discussion" part of the forum. 60 kWh pack consist out of two blocks, each contain 7 sections, with ~450 cells in each of them. It was speculated that in 85kWh pack there are 16 instead of 14 "sections". If anything "cascades"(I personally do not think so), the cascading was probably contained within such section.

Mine IMHO on the matter, something caught small fire in the front of the vehicle (hydrolic fluid, 12v battery wire etc), which in turn ignited whatever was stored in the frunk. It is probably took quite some time till that big of a fire we see in the video to get going. It is not clear how long it took from the moment of incident to emergency teams to arrive, the video could have been easily taken half an hour after Model S stuck that big metal object.

 

[Doug_G]

An short of the 12V battery would be all it took to cause a fire like this. There is no need for a flammable substance in the frunk or on the road, or for involvement of the main battery pack.

Let's wait and see what develops, and not jump to any conclusions.