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Days After A Fiery Crash, a Tesla's Battery Keeps Reigniting (mercurynews.com)

Posted by EditorDavid on from the false-charges dept.

An anonymous reader quotes the Mercury News Six days after a fiery crash on Highway 101 involving a Tesla Model X took the life of a 38-year-old San Mateo man, the car's high-voltage lithium-ion battery re-ignited while sitting in a tow yard, according to the Mountain View Fire Department... The battery reignited twice in the storage yard within a day of the accident and again six days later on March 29. Two weeks later, in an effort to avoid more fires, the NTSB and Tesla performed a battery draw down to fully de-energize it...

On the company website, Tesla wrote "the reason this crash was so severe is that the crash attenuator, a highway safety barrier which is designed to reduce the impact into a concrete lane divider, had either been removed or crushed in a prior accident without being replaced. We have never seen this level of damage to a Model X in any other crash"... Tesla also reported that the vehicle's autopilot function was active at the time of the crash...

The National Transportation Safety Board is investigating the Highway 101 crash and three other accidents also involving Teslas, including a fiery 2014 Model S crash Tuesday in Florida that killed two teenagers. Also under investigation: A Model S crashed into a fire truck near Culver City in January, and the driver reportedly said Autopilot was engaged at the time. And it is looking into a battery fire of a Model X that drove into a home's garage in Lake Forest in August.
Two hours after that story was published, a Tesla smashed into a Starbucks in Los Gatos, California.

34 of 302 comments (clear)

  1. The desperate schmucks... by Type44Q · · Score: 3, Informative

    The desperate schmucks who've shorted Tesla would love nothing more than another headline but the implication here (that Li-ON is even less stable than some of us may have realized) affects Tesla only indirectly... and effects their [viable, prospective] competition equally.

    Eyebrow raising but otherwise changing nothing.

    1. Re:The desperate schmucks... by serviscope_minor · · Score: 2

      (that Li-ON is even less stable than some of us may have realized)

      Even less stable? Given it's a car, the point of comparison is petrol. I mean sure, they don't tend to re-ignite days after but that's only because once they ignite at all they go so fast there's nothing left to reignit ever.

      Back to the battery though, LiPo are known to be fragile and I'm surprised as to how resilliant the Tesla battery packs have proven.

      --
      SJW n. One who posts facts.
    2. Re:The desperate schmucks... by Rei · · Score: 3, Informative

      That said, with the amount of energy that's stored in electric car batteries

      Electrical energy stored != combustion potential energy, and combustion potential energy != energy that can be practically released in normal circumstances (there's five times more potential energy to be released from the combustion of 1000kg of alumium or graphite vs. 1000kg of nitroglycerine, but which one would you rather be next to in a crash?).

      It is not the "energy" stored in the batteries in "lithium battery fires" as you put it. First off, they're lithium-ion batteries, not lithium batteries, and yes, there's a big difference. There's no metallic lithium in lithium-ion batteries unless they've been abused (plating out of lithium at the anode is a failure mode, due to attempting to overcharge a cell or charging at too low of temperatures - both of which are prevented in a proper EV battery pack). The power (not energy) of the cell may provide a (significant) short-circuit ignition source if crushed, but what happens thereout depends on the chemistry of the cell; the fire from a burning cell (in varieties that are capable of burning) is most often the electrolyte (of which there are many varieties). The rest of the cell just isn't that flammable; the anodes are predominantly carbon (graphite or amorphous, sometimes with silicon) and the cathodes are metal oxides. The lithium itself is present as ions (hence the name) intercalated (in small quantities) in the lattices of the graphite and metal oxides.

      What happens in a battery pack, however, is a bit different from an isolated cell. In a ruptured, internally-short-circuiting cell in a battery pack, the heat and contents are released, but they're released into non-flammable temperature-regulated pack coolant. Aka, quenched. Packs also employ a variety of processes to physically isolate cells from each other. Normally, cell failures are self-extinguishing in a pack. The problem with this accident is that it was so energetic that it utterly mangled the battery pack. Which is hard to do, as the pack lies within the wheelbase, but "high speeds into a concrete barrier" is a huge amount of impact force. When storing this pack, there was almost certainly no coolant left, and a lot of damaged cells. Yes, the remaining charge was an ignition source, but it's not what you see physically burning; on its own, a short circuiting cell just makes itself very hot. Anything that happens after that is a result of the consequences of that heat - and more specifically, the results of that heat on the electrolyte.

      Tesla will need to adjust the storage procedures for such heavily damaged wrecks. This appears to be the first case of reignition days after extinguishing in the company's history, but it'll need to be accounted for.

      Either way, the rate of EV in general (and Tesla in specific) fires is much less than with ICEs.

      --
      "WANTED: Sinking ship seeks rats."
    3. Re:The desperate schmucks... by msauve · · Score: 2

      "discharge the battery to the ground?" You might want to Google around about electricity. It doesn't work that way.

      --
      "National Security is the chief cause of national insecurity." - Celine's First Law
    4. Re:The desperate schmucks... by msauve · · Score: 2

      My water pipe goes into the ground, too, but I don't expect to get electricity out of the faucet. Seriously, you lack an understanding of even basic electricity.

      Simply, a battery has two poles, positive and negative. To draw power out of a battery, you connect an electrical load between the two poles.

      There's no ground involved at all. That's why you can carry a cellphone around and it doesn't need to be grounded. It's why an electric car works even though it's electrically insulated from the ground by rubber tires. Connecting a wire from a car battery to earth ground isn't going to do anything at all.

      "Ground" is also used to refer to the part of an electrical circuit which provides sort of a baseline voltage for a circuit. The negative pole of a car battery is often connected to a vehicles "chassis ground." But with that sort of ground, you wouldn't talk about putting power "into the ground." That ground has absolutely nothing to do with earth ground. That AC circuit you mentioned? It has power and neutral wires in addition to that ground wire (which does go to earth ground). All the power flows through those non-ground wires. The ground wire is just for safety. Ground fault interrupter outlets turn off if they see any current going through the ground wire. Ever seen something with a 2 prong cord? - doesn't even have a ground pin.

      Back to that battery. If you just short the poles of the battery with a wire, you get lots of energy, very quickly. With a powerful battery, you might vaporize the wire or have an explosion. And some batteries become unsafe when they're discharged too quickly. So, you need a load with the right resistance so you drain it fast, but not so fast as to be unsafe.

      And that load is going have to deal with all the energy it's absorbing, which will be released as heat. To discharge a full Tesla battery in 1/2 hour would release the heat of over 110 electric space heaters.

      --
      "National Security is the chief cause of national insecurity." - Celine's First Law
  2. Comment removed by account_deleted · · Score: 5, Insightful

    Comment removed based on user account deletion

  3. Duh: drain the batteries ... by jschultz410 · · Score: 5, Insightful

    In any accident that hurts the integrity of the batteries, then they should be drained as standard operating procedure.

    If a gas tank was leaking, then would they just let that go too?

    1. Re:Duh: drain the batteries ... by vtcodger · · Score: 2, Insightful

      "In any accident that hurts the integrity of the batteries, then they should be drained as standard operating procedure"

      Safely "draining" 50 or more KwH of electricity is likely to be a non-trivial job. Especially if the battery is damaged and may have a few broken ground/power connections. You can drain gasoline or diesel into a metal tank. Electrons, not so much.

      --
      You can't see ANYTHING from a car, You've got to get out of the goddamned contraption and walk...Edward Abbey
    2. Re:Duh: drain the batteries ... by sphealey · · Score: 3, Informative

      = = = Unlike gasoline or diesel, which can still ignite after being drained from the tank, electricity is pretty much harmless once you've discharged it into a ground, like say the ground. = = =

      There's a pretty common belief, probably stemming from how we are taught about electricity in 2nd and 3rd grade, that Gaia maintains reservoirs of electrons and positrons at the Earth's core and that electricity will "seek a path to ground", presumably to be stored in this reservoir for future deployment by the various gods/goddesses of lightning, the ghosts of Edison, and Tesla, etc. This is to put a fine point on it not true; if you connect a Tesla battery 'to the ground' (presumably by sticking some sort of metal toothpicks in the nearest soil and connecting the battery leads to it) at best you will get some slightly warmer soil in the vicinity of those toothpicks while the battery pretty much holds its original charge. The emergency services would have to carry around 1 MW resistors to use as the energy sink, and those things are not small or cheap ( http://www.jovyatlas.com/ja/Te... )

    3. Re:Duh: drain the batteries ... by Rei · · Score: 2

      I remember all the people over in Shortsville writing articles encouraging people not to "go wobbly" when Tesla was down in the 250s/260s, but to double down on the shorts.

      $306,85 today ;) And analyst factory checks showing that production appears to be up to nearly 3k per week now. Now you've even got long-time Tesla-despising shorts going long just to cash out on the squeeze of their fellow shorts. It's going to be a $10+B bloodbath.

      Now that their old production canard is going away, they'll have to revert to their fallback, "But Tesla loses money on each Model 3!". Yes, that would be meaningful in a world where the cost of a vehicle exactly equaled the cost of the steel/aluminum and 3rd party parts that went into it, and the cost of labour and hardware depreciation was zero. Meanwhile in the real world, if you're producing an average a bit over 1k per week (Q1) with labour and hardware designed for 5k per week... well, of course that's going to be running a negative. It's impressive that they were only running a ~17% negative margin on Model 3 in Q1.

      --
      "WANTED: Sinking ship seeks rats."
  4. Re:Tesla smashed into starbucks by jeff4747 · · Score: 3, Insightful

    I'm glad my non-electric car has a real park setting on the transmission. One where there is a physical cable attached to the selector that engages a pawl to lock the transmission.

    Electric cars have those too. It's required by federal safety standards no matter the propulsion method.

    And people "thought the car was in park" lots of times in ICE vehicles.

  5. I don't get it by Anonymous Coward · · Score: 5, Funny

    Can someone please provide a car analogy?

  6. Re:Tesla smashed into starbucks by skids · · Score: 2

    It's required by federal safety standards

    ...for as long as those last.

    All the by-wire stuff spooks me, I'll never buy a car that doesn't have permanent direct mechanical coupling backups for steering and brakes... Nissan's dont-worry-the-coupling-reengages-if-the-power-fails doesn't cut it, even if it can get passed the regulations.

    --
    Someone had to do it.
  7. So where's the "Honda crashes into bus!" stories? by tempo36 · · Score: 4, Insightful

    The battery catching fire is an interesting point. I'd be interested to know if the emergency responders initially followed the published guidelines for cooling the battery or if they stopped when they stopped seeing flames. Regardless, it's an interesting point and an important one for the future.

    Regarding the rest of the OP's posting...yeah, 2 teens died in a Tesla in Florida while speeding 50-60 around a corner marked for 30 mph. Yes, a lady crashed her car into a Starbucks. Where are the headlines about some random kid who died in a pickup truck this weekend? I'll bet you $50 it happened. Or the old lady in her Ford Fiesta who ran into a parked car? I'll put $20 on that one. What, no national headlines on those ones? What gives? Or do we think miraculously owning a Tesla makes you immune to being a stupid/careless/human driver? I didn't know Musk was advertising that feature. Is Ford? Honda? Lexus?

  8. Re:Tell me again how Lithium Ion batteries are saf by bobby · · Score: 3, Informative

    Any energy storage system will have inherent danger, and the more concentrated it is, the worse the possible result. But you knew that.

    As bad as battery fires are, they don't spread like a chemical fuel fire can and often does.

  9. Re:At what point do tax payers stop subsidizing Te by steveha · · Score: 5, Insightful

    I am not very sore at the massive per-unit subsidies that Tesla's above-average wealthy customers are getting on cars

    So not very sore that you described it using passive-aggressive terms. But yep, Tesla gets the same electric car tax credit that all the other battery electric vehicle car manufacturers can also take advantage of. Unless you are going to claim there is a special subsidy just for Tesla?

    News flash: when the government wants something to happen, one lever they use is tax breaks. The government would like to see electric cars happen sooner, so they gave tax breaks. To everyone. Equally.

    And yes, new technology is more expensive than older established technology, which in turn means that the initial customers might be more affluent. Not news.

    NTSB is basically deputized to solve private sector problems at taxpayer expense. How much longer does Tesla and it's financiers get this free tax benefit?

    NTSB is investigating because of the lithium ion batteries, the same battery technology used in every modern electric car. How much longer does GM (Chevy Bolt), Nissan (Leaf), VW (eGolf), Ford (Focus Electric), BMW (i3), etc. etc. get this free tax benefit?

    NTSB has, over the years, spent quite a lot of time investigating gasoline car crashes. They've slowed down a lot because they've got a solid knowledge base.

    So it's patently unreasonable for you to claim that this is somehow special treatment given Tesla. Tesla cars are the most popular electric cars right now, even though they are expensive; so there are crashes from time to time, just as with gasoline cars.

    If the NTSB investigates a Nissan Leaf crash, will you rail against Nissan, or is Tesla just special?

    --
    lf(1): it's like ls(1) but sorts filenames by extension, tersely
  10. Re:At what point do tax payers stop subsidizing Te by tempo36 · · Score: 4, Insightful

    Someone give this guy a mod point. Seriously.

    To expand...danheskett...the person bitching about the NTSB "solving private sector problems" on the taxpayer dime. You realize what you're complaining about is, literally, the government doing the job we pay them to do right? Are YOU going to hold a car manufacturer accountable for putting a dangerous product on the road? Were you personally going to pony up the cash to fly out to the crash site, check the forensics, go over the debris field, and make sure that what happened was a genuine accident and not the result of some guy cutting corners in the factory to improve his bottom line by 1%?

    No? You weren't offering to do that? Gosh, I guess it's a good thing we all pay taxes and the NTSB does this stuff so that the rest of us have at least some slight reasonable reason to believe that manufacturers are making quality products. Yes, even Tesla...but also GM, Ford, Acura, Porsche, Kia, et al. They aren't doing those company's jobs for them. They are, quite literally, capable of shutting those companies down if they find a critical flaw in their product. That's not doing their job for them, that's keeping your disingenuous, passive aggressive, Neanderthal butt safe.

  11. Re:Musk: Safe Enough to Strap to Your House by Phics · · Score: 5, Funny

    ...and then hope and pray your house doesn't slam into a safety barrier at high speed while you're asleep at the wheel.

    --
    There are two types of people in the world; those who believe there are two types of people, and those who don't.
  12. Re:At what point do tax payers stop subsidizing Te by Anonymous Coward · · Score: 3, Insightful

    Yes, but we will all benefit from the electric cars eventually. As the batteries get better and the prices come down, they'll be something that most people can afford to use. Unfortunately, getting to that point is rather expensive, hence the subsidies.

    In the mean time, people in places that have clean power generation benefit from the reduced emissions from the electric cars being sold.

  13. Re:So where's the "Honda crashes into bus!" storie by tempo36 · · Score: 2

    Yep. I don't think I know anyone who hasn't ever been involved in a car accident. If there are Tesla's on the road, they'll be in accidents. It's not worthy of headlines unless the things go up in a mushroom cloud when hit or something.

    Yeah, when I rear ended someone in my Lexus, I don't recall a Mercury News headline. But maybe I just wasn't paying attention.

  14. Re:So where's the "Honda crashes into bus!" storie by Gravis+Zero · · Score: 4, Informative

    So where's the "Honda crashes into bus!" stories?

    Right here

    Where are the headlines about some random kid who died in a pickup truck this weekend?

    Oh please! He didn't die in the pickup truck.

    Or the old lady in her Ford Fiesta who ran into a parked car?

    Apparently, not a lot of old ladies drive a Ford Fiesta... but when they do, it's epic. ;)

    --
    Anons need not reply. Questions end with a question mark.
  15. Dodge: opening the door while stopped engages Park by raymorris · · Score: 3, Informative

    > For whatever reason people make this mistake all the time

    In my Dodge, if I open the door while the car is stopped, it automatically goes into park.

    Humans screw up all the time. Good systems are designed so that mistakes that happen "all the time" don't cause your car to drive through a Starbucks.

  16. Re:So where's the "Honda crashes into bus!" storie by whoever57 · · Score: 2

    I agree with you, 100%. However teslas are for the rich, we can't afford them,

    Speak for yourself. Some of us can afford a Tesla.

    --
    The real "Libtards" are the Libertarians!
  17. Re: So where's the "Honda crashes into bus!" stori by phantomfive · · Score: 2

    Worth mentioning that every car today has a giant tank of energy. A gas tank is in no way safe.

    --
    "First they came for the slanderers and i said nothing."
  18. Re: Tesla smashed into starbucks by nukenerd · · Score: 2

    I've never driven a car that had a special park gear.

    Sounds like you have only ever had manual cars. Automatic transmissions always (AFAIK) have a park position with which a mechanical sprag engages with a toothed wheel to prevent the propellor shaft (and hence the wheels) from turning. The arrangement is provided as the equivalent of the recommended practice of leaving a manual car in gear when parked - as a last resort in case the parking brake fails for some reason like its cable breaking. What is being discussed here is how that sprag is moved - by a direct lever or cable (ie mechanically), or via an electric actuator controlled by a microchip (ie by wire).

  19. Re:Tesla smashed into starbucks by sjames · · Score: 4, Informative

    Well, let's see, I have had a car suffer complete electrical failure while driving it before. Because it had a mechanical linkage between the steering wheel and the front end, I just pulled over. Because the brakes were a simple hydraulic link, I was able to stop.

    I also had a brake failure once. Because the emergency brake was a simple cable link between pedal and the brakes, I was able to stop safely.

    Drive by wire would have been a problem in either event.

  20. Re:Tesla smashed into starbucks by Rei · · Score: 3, Insightful

    Not with the previous release of AP2. It filtered out stationary objects to avoid spurious detections of hazards that were actually on the edges of the road.

    The latest version - ironically, right before the accident (Tesla updates have a slow rollout process, so the driver almost certainly hadn't gotten it yet) - no longer appears to filter out stationary objects.

    The big question is: why are we still talking about this accident that happened months ago? 3300 people die per day in car accidents. There's virtually no news in any of them, but every time it's a Tesla (AP or not), it's huge news. Which creates a misleading perception, given that Teslas have such a low rate of fatalities per mile (a point that's on this site frequently used against Tesla in arguing that Autopilot doesn't actually make a driver safer - the argument is that the vehicles are physically safer to begin with, so you can't credit that to Autopilot).

    --
    "WANTED: Sinking ship seeks rats."
  21. How many Tesla fire should happen? by 140Mandak262Jamuna · · Score: 3, Interesting
    Tesla is fast approaching 200K cars delivered in USA, let us round it up and call it 125 K on the road since 2018 Jan

    There are 100 million ICE cars on the road in USA. And NTSB reports there are 500 vehicular fires that kill 100 people every day.

    Since 1 on 800 vehicles on the road are Tesla, we should expect around 0.625 Tesla fire every day or about 18 fires a month or 60 Tesla fires in the first quarter of 2018.

    Since every Tesla fire gets national news coverage, I would assume at most two fires happened in that period.

    I would conclude Tesla prevented 58 vehicular fires in the first quarter of 2018.

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
    1. Re:How many Tesla fire should happen? by ledow · · Score: 2

      Skewed by:

      - Vehicle usage ("vehicle" includes long-distance trucks, motorbikes and all sorts, Tesla only really make cars)
      - Journey distance (cars can do three times the distance of a Tesla, so are used for different things)
      - Vehicle age (adjust for 15-year-old falling-apart things with rusted mounts for fuel lines, etc.)
      - Other causes (e.g. deliberate arson)

      Hell, most Tesla in the UK wouldn't have even had their first MOT test yet. They'll still be inside the service warranty. They are literally not old enough for the law to consider them capable of being unroadworthy yet, unless there's been some absolutely disastrous documented and reported cock-up in their engineering.

      There are lies, damn lies and statistics. I don't think Tesla's are any more likely to catch fire than other electric vehicles, or that electric vehicles in general are any more likely to catch fire than ICE vehicles. (Note that this does not even imply that Tesla's are less likely to catch fire than ICE vehicles on its own - statistics are weird!).

      But it does raise a question of whether they've designed it correctly and issued the correct advice to the relevant authorities. That car wouldn't have been released to a towing company if the fire service thought it could reignite. And yet it did.

      P.S. Courting the media for every piece of hype ends in tears if they turn against you and report every counter-piece too. That's what happens with Tesla. If you weren't claiming your cars were so superior and intelligent and infallible etc. then they wouldn't be able to go "Yeah, right, what about this..."

  22. Re:Tesla smashed into starbucks by mixed_signal · · Score: 3, Insightful

    "Your simple mechanical systems aren't as foolproof as you think." No one said they are foolproof. The discussion here is that the system still works (somewhat) even with no electrical power. In addition, mechanical systems tend to fail slowly and give noticeable indications of problems well before actual failure. Electrical and software failures can be sudden, e.g. a connector fails (common) or a bug.

  23. Re:Tesla smashed into starbucks by SlaveToTheGrind · · Score: 2

    I think that this is the least likely to be related to a drive by wire and will probably come down to driver error. For whatever reason people make this mistake all the time - they jam the wrong pedal, make the wrong drive mode selection, etc.

    Pedal errors do happen, but this particular kind is a rare bird indeed according to this study:

    Before leaving the serious error category, it should be mentioned that there were only two instances in which the subject depressed the accelerator instead of the brake. In both cases the subject recognized the error immediately and made a correction. There were no instances, in other words, in which the subject persisted in mistaking the accelerator for the brake.

    And in this particular situation, the driver would have had to keep that pedal jammed for a long time and through lots of chaos. Look at the setup where the accident happened. The car had to first jump the curb, which takes a lot of force and gives the driver plenty of feedback that something is very wrong, and then still managed to run across the entire sidewalk area and hit the building with enough force to embed itself almost fully through the wall.

    Given all that and the fact that we're talking about a car that has full control of its faculties and regularly makes bad "decisions" about how to use them, Occam says it most likely wasn't the driver.

  24. Re:So where's the "Honda crashes into bus!" storie by omnichad · · Score: 2

    I think you have that entirely backwards. An important part of budgeting is not wasting money.

  25. Re:Tesla smashed into starbucks by sjames · · Score: 2

    My complaint is that too many cars have no backup if the electrical system goes out. You lose steering, shifting, and regular and parking brake all in one shot.

    On older cars, steering, main brake, shifting, and parking brake are independent systems. Yopu are MUCH MUCH less likely to have 4 failures at the same time than one.

  26. Re:So where's the "Honda crashes into bus!" storie by tempo36 · · Score: 2

    I'm sure there are things in your budget I'd consider "wasteful" and I'm sure there are things in mine that you'd consider wasteful.

    A household "budget" by definition is "an estimate of income and expenditure for a set period of time" and if you run yours and you can afford something while meeting the other obligations that you need/should cover, then that's a successful budget. Whether it is irresponsible is a much bigger question that every family/city/country has to decide independently and as a unit.

    Also, totally not the point of the original post which was about disproportionate coverage of Tesla compared to other similarly priced vehicles (and far disproportionate compared to less expensive ones).