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Electronics & Test

Tesla to NHTSA: Investigate Our Model S Fires

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naperlou
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really?
naperlou   11/20/2013 9:02:01 AM
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Musk talks a good game.  On the other hand, there are a lot fewer Tesla vehicles than there are ICE cars.  As I wrote in a comment to a previous article about this, Musk's characterization of the statistics is misleading, at best.  You have to look at cars built to the same standard, for example.  That means current model cars.  There are plenty of cars on the road that are older. 

That aside, I wonder how many "regular" cars experience a breach of the floor from metal road debris.  I have not heard of any.  That does not mean that there are none.  I just wonder why we don't hear more about it.  I once hit a piece of metal on a road and it broke a rim, as well as destroying the tire.  I put on the spare and got a new rim (and tire) and that was that. 

One other thing to remember, the lithium ion battery fire is much hotter and goes faster than a fire from gasoline.  It is a different chemistry and different configuration.

LetoAtreidesII
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Platinum
Re: really?
LetoAtreidesII   11/20/2013 10:12:51 AM
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I agree, lets compare the last 2 years of mercedes or BMW to the Tesla and see what the fire #'s are.  With a Mercedes you have a similar class of car and driver.

tekochip
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Re: really?
tekochip   11/20/2013 10:41:27 AM
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naperlou;

 

I know of one case in particular that happened in our own state.  That would be the Willis family van that had its gas tank pierced when it ran over a truck tailight assembly.  The fire killed six children and the resulting scandel exposed Governor George Ryan's license for bribes policy and sent him to prison.  I'm sure there have been other cases, but that one certainly received a great deal of press.

Charles Murray
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Re: really?
Charles Murray   11/20/2013 7:05:23 PM
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I agree, naperlou. It's only fair to compare apples to apples. And the apple in this case is a brand new luxury car. I wonder what the numbers would be for a six-month BMW, Mercedes, Audi or Lexus.

RogueMoon
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Platinum
plenty of fires for all
RogueMoon   11/21/2013 9:12:33 AM
I'm glad to see an official review of the situation.  The title suggests that Tesla asked for it?  I'm not sure that the future of electric vehicles is at stake (while lumping global warming into the mix), but if the NHTSA wants to investigate the Tesla S fires, hey?, so be it.

There's an equal chance of any vehicle (ICE or electric) encountering a large piece of garbage on the road and getting a wallop on the underside.  The issue is what happens after that event.   Comparing stored energies is not the whole story.  

A gas tank is an unpressurized fluid vessel that can often take a dent or even a puncture, but only sometimes creating a fire if, and only if, there is an ignition source created and sustained at an area that happens to have a flammable mixture which also doesn't always happen.

A battery has stored potential between many many cells.  Shorting a group of them together by smashing some together at the source of the wallop often gives you an energy release.  There are safeguards in the battery designs and the arrangement is carefully chosen, but the physics leading to catastrophic energy release are very different.  This has to be considered.

The funny thing is that for electric cars to improve to better compete with ICE vehicles they will have to INCREASE their energy density, meaning more stored energy in the same or smaller package.  By a factor of 10 according to Mr. Musk.

This is only a hiccup in the course of proving out a new technology on the road dealing with real issues of real road conditions.  It is by these trials by everyday situations does any vehicle become a proven and trusted design.

Charles Murray
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Re: plenty of fires for all
Charles Murray   11/21/2013 5:06:42 PM
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Yes, RogueMoon, Musk says that NHTSA asked for the investigation. In truth, though, we don't know asked for what first. NHTSA says their investigation is independent of Musk's request.

Watashi
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Platinum
Re: really?
Watashi   11/21/2013 9:45:30 AM
You are correct – the Tesla folks need a course in statistics.  2 of VERY FEW cars on the road is statistically more significant than say 100's of the 10's or 100's of millions of conventional vehicles that have graced the same byways.  It also doesn't help that a specific failure mode is repeated.

Mr. Musk sounds like a real environmental zealot in his statements.  I don't know if he is really an activist or if he just understands that appeals to the market niche for his vehicles.  Either way; it is not good for his future.  Brash statements full of alarmist buzz words and a little dishonesty don't sell very well to the broader public. Startups in the relatively young electronics industry can get away with eccentricity, but people expect more maturity from car manufacturers. 

Who cares if you are buying a couple hundred dollar device from a nut that breaks a year later?  When you put down BIG money on a product that you have realistic expectations of being able to use for decades; you expect more than an attitude and an excuse.

If EVs are to have a chance in the market, they need to be seen as just another car with some very novel features.  The advantages/disadvantages of electric vehicles aside, the market needs some level of comfort with the vehicle to have confidence that it will meet their expectations as a mode of transport.  Like it or not, these expectations have been shaped by a century of ICE vehicle use and improvement.  ...and honestly, the bar is set pretty high!  

Except for GM :)

GTOlover
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Platinum
Re: really?
GTOlover   11/21/2013 10:12:14 AM
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Watashi, Mr. Musk has multiple businesses all dependant on government money. Either in the form of tax credits/subsidies, loans, and grants. So he is simply spinning the political correctness line for self-preservation. He may actually believe it, but he is also running a business.

In the end, I think the NHTSA investigation will not reveal anything dramatic and will make minimalist recommendations to negate any of the public fear of EVs. We may even be told how the "experts" agree that EVs are the safest cars on the planet.

Be careful about bashing GM, my beloved GTO is a GM :)

Watashi
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Platinum
Re: really?
Watashi   11/21/2013 11:04:24 AM
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Sorry, I am a Ford and Mopar guy so GM is the natural enemy (but I would take an old GTO, Chevelle, Firebird, or Camaro in a heartbeat).

I agree with you.  Musk knows the game and his ventures depend on government largess.  It is just annoying to see how radical and extreme the party line has become with those people.

Charles Murray
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Re: really?
Charles Murray   11/21/2013 5:15:20 PM
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You're right about Tesla's need for government money and environmental credits, GTOlover. Although it doesn't get a lot of attention, the credits that Tesla gets for selling ZEVs is substantial. The LA Times did an article on this, pointing out that Tesla can get up to $35,000 per car, in addition to the state and federal money they get. http://articles.latimes.com/2013/may/05/business/la-fi-electric-cars-20130506

btwolfe
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Gold
Re: really?
btwolfe   11/21/2013 10:39:21 AM
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naperlou, I'm not sure how you can say a lithium ion battery fire "goes faster". The lithium reaction with water certainly burns hotter, but speed is affected by multiple factors. Care to elaborate?

naperlou
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Re: really?
naperlou   11/21/2013 11:23:54 AM
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btwolfe, I am basing my statement on this incident (http://www.thenanfang.com/blog/shenzhen-electric-taxi-may-have-caught-fire-due-to-leaking-battery/) in China. 

I am also concerned that the Tesla batteries require active measures to cool them.  They are made up of large numbers of small cells each of which must be individually monitored and controlled.  This is probably part of the issue with cost and weight as well.  Compared to fuel in an ICE, this is crazy.  So far, electric vehicles have been sold to higher end buyers in small numbers.  Look at the history of autos on the road and should appreciate my concern.  As a vehicle gets older one tends to not fix things or to do it oneself.  Since it is not a classic and is always going to be eclipsed by newer models, this approach itself could be a recipe for disaster.  But I digress.

I am not sure that I have answered your question in general, and I have not found a good source of information.  As Tesla points out, the battery has armor built into it which may account for the ability of passengers to get out.  This is good, since the fires were difficult for firefighters to put out and in the latest case, at least, melted pavement. 

btwolfe
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Gold
Re: really?
btwolfe   11/21/2013 11:44:35 AM
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naperlou,


I can't conclude anyting about the speed of lithium fire based on that article. It says "they were incinerated" but that's just an inflamatory (pun unavoidable) term for burn. Given that the accident was from a 180kph collision, they were probably in no shape to exit the vehicle quickly anyway.


My experience with lithium is that it burns hot, but slowly. I used to play with pigs of the stuff as a kid, so I have some empiracle knowlege of it's burning characteristics. BTW, don't ask how I got the material. Anyway, it's the heat of the reaction when lithum is mixed with water and the resulting hydrogen gas that's the real danger. If you don't vent the gas, you're going to have a serious problem.

Tool_maker
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Platinum
Re: really?
Tool_maker   11/21/2013 12:48:36 PM
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@naperlou: I disagree that Musk talks a good game. I remember from n argumentation and debate class I took a long time ago, that the weakest possible arguements involved a, "Look at the other guy" statement. What difference does it make if ICE vehicles can become involved in fires when the discussion is about a Tesla fire. He should make his arguement solely about the Tesla and how safe it is. We already know about ICE vehicles and hundreds of millions of us have daily experience with them.

jhankwitz
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Platinum
Re: really?
jhankwitz   12/13/2013 2:43:17 PM
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naperlou - The reason we don't hear about fires in other cars (by the way, we've had 4 this past week in the SE Wisconsin area) is the same reason we hear about working conditions at the Foxcon factory where iPhones are made.  Readership - readership - readership.  Tesla, like Apple, is at the leading edge of the technology.  Makes no difference that working conditions at Android factories is much worse, it only matters in people's minds what is happening at the hot leading companies.

Davek3gau
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Gold
Model S fires
Davek3gau   11/21/2013 10:12:00 AM
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I am not trying to make excuses for EVs but I wonder what would happen if ICE gas tanks were put on the bottom of the cars in the same positions the EV batteries are typically put? 

Most gas tanks that I know of are to the rear of the vehicle and pretty well protected by other metal parts of the vehicle in front of them.  Unfortunately the batteries require much more space than a gas tank and are a whole lot heavier so have to be put low and spread out over more of the bottom area of the vehicle so are easier to be struck by road debris.

radio-active
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Iron
Tesla "fix"
radio-active   11/21/2013 10:28:06 AM
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I find it interesting that the "fix" is to raise the car's ride height via the electronic suspension at highway speeds. This will no doubt decrease driving range due to increased wind resistance and turbulence under the car. Quite a band-aid.

It's only a matter of time before some such incident so badly damages the battery that the car is immediately disabled from low battery voltage or no voltage. It'll be very interesting to learn how well the vehicle and occupants fare in such a situation. Will the car still warn the driver? Will he be able to stop it, or steer it, or even unlock the doors and get out?

bpenfold
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Iron
prefer EV fire
bpenfold   11/21/2013 11:30:09 AM
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If I must be involved in an auto fire, based on everything I've seen, I would pick a lithium-ion fire. I would have a few more seconds to walk out.

I'm still amazed how the Mexican Tesla crash victim walked out alive. It reminded me of The Roadrunner or Wile E. Coyote.

-Barry

Charles Murray
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Blogger
Awaiting NHTSA
Charles Murray   12/5/2013 7:09:50 PM
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We'll be watching to see how this plays out in the NHTSA investigation.

Charles Murray
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Blogger
Good reason for coverage
Charles Murray   1/6/2014 6:29:16 PM
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Actually, there are good reasons for coverage of this subject: To much of the public, electric cars are still a curiosity. And the public has become especially curious since the Boeing overheating incidents. Also, comparisons to gasoline-burning cars aren't completely appropriate, according to the MIT Technology Review: "...these figures are really comparing apples to oranges," the Review stated in November. "Only four percent of vehicle fires are caused by collisions -- the rest are largely the result of mechanical and electrical failures, which isn't surprising when you remember that a large fraction of the cars on the road are old and wearing out." These points could be debated on both sides, but the debate needs to be visible, not behind the scenes. Put it another way: If the press sat on the Tesla stories and didn't report them, how would the car-buying public react?

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