Tesla CEO Musk: Boeing 787 Batteries 'Inherently Unsafe'

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'Revenge of the Electric Car' premiere: Elon Musk arrives in a Tesla Roadster

'Revenge of the Electric Car' premiere: Elon Musk arrives in a Tesla Roadster

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Tesla Motors CEO Elon Musk is hardly shy and retiring.

He tweets out random financial results, states as fact things that haven't quite happened yet, and regularly speaks his mind.

Yesterday, he described the troubled Boeing 787 Dreamliner's battery pack design as 'inherently unsafe,' which could add fuel to the...ahem...fire.

It came just one day after his offer to help Boeing resolve its problem with fires in the 787's lithium-ion packs, designed by Japanese battery-cell company GS Yuasa.

(It's worth noting that SpaceX, the other company Musk runs, competes directly with Boeing for certain government contracts for space-launch vehicles.)

Musk, who has run Tesla Motors [NSDQ:TSLA] for several years, laid out his thoughts on battery design in a detailed e-mail to the website Flightglobal.

In it, he termed the architecture of the GS Yuasa battery packs supplied to Boeing "inherent unsafe," and predicted more fires from the same causes due to its design.

Specifically, Musk criticized the use of large-format lithium-ion cells "without enough space between them to isolate against the cell-to-cell thermal domino effect."

He also noted that when thermal runaway occurs in the larger cells, more energy is released by the single cell than comes from a small-format "commodity" cell, of the type used by the thousands in Tesla battery packs.

And he went on to highlight what he viewed as the dangers of batteries using those large-format cells, saying they have a "fundamental safety issue" because it's harder to keep the internal temperature of a large-format cell consistent from the center to the edges.

Not surprisingly, Mike Sinnett--Boeing's chief engineer for the 787 project--counters that the company designed the pack to cope with not only a single cell failure but to contain runaway thermal events as well.

The 787 battery problems have sparked a deluge of news coverage, with the Seattle Times noting yesterday that Boeing had numerous problems with the batteries before the fires that led to the grounding of all 787 planes worldwide.

Boeing 787 Dreamliner

Boeing 787 Dreamliner

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The chemistry used in the Boeing 787 cells is not the same as that used in today's electric cars, a point largely overlooked by many reporters.

But Musk's comments highlight a second issue: the use of large-format lithium-ion cells (some roughly the size of a very thin paperback book) versus the smaller commodity cells (somewhat larger than a AA battery) that Tesla uses.

Musk's critique, although he didn't explicitly say so, could be extended beyond the 787 Dreamliner to indict the pack design of all electric cars that use large-format lithium-ion cells.

Those include, oh, every single modern plug-in electric car except the Tesla Model S.

Tesla Motors is the sole maker that builds its packs out of thousands of small 'commodity' lithium-ion cells (from Panasonic, for the Model S) rather than using hundreds of large-format cells.

Battery-pack engineering is a complex, multifaceted art.

There's the physical design of a large, heavy component that must be engineered into the vehicle's structural design.

There's positioning of the cells inside the pack to protect against thermal runaway.

Tesla Motors - Model S lithium-ion battery pack

Tesla Motors - Model S lithium-ion battery pack

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There's thermal conditioning, in which a pack is passively or actively heated or cooled to keep its cells within a desired temperature range, both extending their life and reducing the chance of catastrophic cell failure.

Each electric-car maker takes a somewhat different approach: Nissan uses just passive cooling in its Leaf battery electric car, but has had no recorded fire incidents at all to date.

It has, however, had problems with reduction in energy capacity early in the life of cars that cover high mileages in high temperatures.

The Chevrolet Volt, on the other hand, uses only two-thirds of its pack energy and has active liquid cooling for its pack (as does the Model S).

So has Musk has implicitly slammed the pack designs of the Nissan Leaf, Chevrolet Volt, and a host of other electric cars with battery packs of 16 kilowatt-hours or more?

If so, is this a good strategy for the CEO of a startup electric-car maker?

Leave us your thoughts in the Comments below.


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Comments (25)
  1. Firstly, with the car batteries that are not Cobalt based, thermal events may be less likely and proceed more slowly if they do occur due to slower burn rate.

    Secondly, I wonder if they are barking up the wrong tree here with the Boeing battery. Seems likely that there is a fault in the charger. This could cause a problem in any battery. Not sure the packing or chemistry make the battery "inherently unsafe."

    Lead Acid batteries explode if overcharged. That doesn't make them "inherently unsafe".

    Let's see what the NTSB says. They seem to be quite thorough.

  2. Probably he's just trying to take advantage of the situation and benefit from the attention for free, for Tesla and SpaceX.

  3. Musk has really no idea about what he talks. The car makers use a "safer" chemistry than Musk's laptop computer batteries. Even Panasonic's new 18650A NCR, battery which is what Tesla is using is better but still has raw Li metal in the cathode. NO ONE IN AUTOMOTIVE WILL USE THIS TECHNOLOGY SINCE FAILURE MODE IS CATASTROPHIC! Hit one on these batteries with hammer and flames shoot out, penetrate a cell with metal and it burns very hot! Tesla is playing the odds game, but eventually they will have a "thermal incident." It may be an severe accident, it may be a software glitch, it may be a bad battery electronics issue but it will happen.
    Current car companies use Li iron phosphate or Li manganese oxide which don't exhibit these issues.

  4. Since we all know not to trust Mr. Marks when it comes to Tesla, can someone else please comment on the claims he raises here for those of us who can't comment technically?

  5. Mr. Marks says, "Musk has really no idea about what he talks." Mr. Marks, would you say the same thing about Donald Sadoway, MIT professor of electrical engineering? After all, when Professor Sadoway is asked about Musk's assessment, he's quoted in the Flightglobal article as saying "I would have used the same words."

  6. Matthew, has Mr. Sadoway actually seen the components or data in question? He certainly may have and that's why I ask here but if not, how would he be able to comment knowingly about a specific new system that was just developed?

    This just doesn't jive with the announcement on Monday by both the FAA and Japan's Civil Aviation Bureau that the batteries are not the problem here. I'm not claiming that's authoritative, either, just that he's claiming something that people who have presumably seen the actual data and components are completely rejecting as a root cause.

    You may be completely correct but can you explain, please? A lot of cognitive dissonance here...

  7. To refute the claim that Musk doesn't know what he's talking about, I was merely pointing out that another expert agreed with his assessment. I don't know Professor Sadoway's full involvement but I find it doubtful he'd risk his reputation by commenting on something for which he lacks context. Furthermore, I don't read Musk's assessment to conclude the battery architecture is the root cause. Instead, he's saying a better battery architecture may help prevent a catastrophic domino effect when something does (eventually) go wrong. Finding the root cause to be an issue external to the battery won't mean Musk is wrong.

  8. Prof. Donald Sadoway is well-known for his research in the field of new battery technologies, and indeed not one to make such statements lightly.

  9. Matthew and Norbert. Thank you. I think general knowledge is very different than knowledge gained from an actual inspection of the system, components and data, but I'm not trying to question anyone, just understand where the different viewpoints come from. And whether or not a professor is well known or apt to make statements lightly, his viewpoint may be less valid if he hasn't seen what others have in this case. If that is the case, of course.

    As I commented previously, this will be interesting to see what Boeing comes up with.

  10. Mr. Marks says, "Musk has really no idea about what he talks." Mr. Marks, would you say the same thing about Donald Sadoway, MIT professor of electrical engineering? After all, when Professor Sadoway is asked about Musk's assessment, he's quoted in the Flightglobal article as saying "I would have used the same words."

    True, Elon Musk has a physics degree from the University of Pennsylvania and a business degree from Wharton. I have a minor in Chemistry and a Pharmacy degree too. I would definitly seek advice from Elon Musk for he has helped to engineer the best EV the world has seen. Tesla Model S is way ahead of the big 3 in EV Technology, Not too bad fro a Silicon valley startup.

  11. Hey - did you catch that CNN article about the woman whose car blew up when she hit the button to open the trunk? Wow, who could have predicted that?

  12. Note to self - do not let Richard Marks near your Model S with sharp metal or a hammer.

  13. a couple of tesla Roadsters have been seriously racked up,
    http://www.rpmgo.com/cars/d/34999-2/tesla_roadster_crash_france06.jpg it appears the batter packs are reasonably tough or well armored.

  14. There are more comments in this thread
  15. I don't have the technical expertise to comment on the technical issues, so I'll leave those alone here. I did just read, however, that both the FAA and Japan's Civil Aviation Bureau completely cleared the battery maker, GS Yuasa, on Monday.

    I do wonder how they finished their study so quickly since it started only on January 21. I'll share the news, for whatever it is worth (it's on the Automotive News web site, and presumably many others' as well) but it will be interesting to see what ends up happening here.

    I tend to think that Musk will look like an idiot if the problem is indeed elsewhere, but as others have noted, he's also a salesman for his SpaceX company, too, so I'm willing to give him the benefit of the doubt here.

  16. The Hindenburg was also cleared by Germany

  17. Nobody is shrewder then Elion Musk and really love his brilliance him but would not trust him.His savageness with competitor's and huge ego has to make these comments suspect.Just take a look at how he with justification impaled Henrik Fisker. Boeing better wake up and get this sorted or Elion will be taking away there bread and butter

  18. It makes me think of the famous fire that killed so many the German "Hindenburg" Hydrogen filled balloon. It was discovered lately that the Hydrogen WAS not the MAIN culprit but the HIGHLY flammable skin of the cigar-shaped ship. Could it be that the batteries are NOT the main problem???

  19. Maybe Musk feels that attack is the best defence here. Boeing's engineering failures are giving lithium ion batteries a bad name which is not what a car company that sticks thousands of them in every car they make needs.

    So turn the lemon into lemonade and present little Tesla as giant Boeing's saviour with its superior knowledge of batteries.

    It's a risky strategy though. Lots of people deeply recent him and will try to use his strategy against him.

  20. Given that several articles (including one at Greencarreports) mentioned that the Roadster battery cells (not the Model S) have a similar basic chemistry, Tesla couldn't remain simply silent. So I think Elon's offer, to help Boing in determining the cause, was a very constructive way to participate in the discussion. As I see it it, after Boing apparently declined, he had to speak from a general point of view, given available information, and point out the factors he could identify from his position. Which turned out to be noteworthy.

  21. The general public is completely unaware that there is no such thing as "the" lithium-ion battery but that it is in fact an extended family of related chemistries with widely varying properties. If one member of the family gets into trouble the whole family is branded guilty in the public mind. I think that's why Musk made his move.

  22. I personally lack the expertise to directly comment on the battery problem(s) or the solutions. However, I would like to say that Mr. Musk is ‘golden’ in my mind. His success with Tesla Motors and SpaceX has made me a believer. I just took delivery of a Tesla Model S and it puts to shame every other car I have driven. Virtually everything he said about the “S” came true: the price, the features,the charging, the Super Chargers, and delivery ( in my case four months later ). These goals were set 3 years ago! Regarding SpaceX they have already successfully docked with the Space Station – twice. SpaceX has achieved unparalleled success.

    Bottom line, Mr. Musk might know what he is talking about.

  23. As an update, the NTSB determined the fire was in fact a short within one of the battery cells, which then led to a thermal runaway event. So I'd say Musk was absolutely correct and Boeing's terse remark that it was "engineered" against those events was large on talk and small on engineering.

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