It seems to me that Lithium Ion battery technology has not reached the maturity that resulted in grounding 30+ aircraft, at millions of dollars a day, regardles of any power to weight benefit. If a car has a fire you can quickly pull over and get out. If an aircraft has a fire in flight what do you do?
At the time the US government certified Boeing's 787 Dreamliners as safe, federal rules barred the type of batteries used to power the airliner's electrical systems from being carried as cargo on passenger planes because of the fire risk.
Boeing appears to have taken gamble and lost. Poor design, poor engineering, poor implementation or.... eventually we will know.
There are several lithium ion chemistries available and the cobalt based battery is well known to be thermally unstable. Recall computer laptop fires?
If a 'safe' chemistry had been considered, e.g. manganese based lithium then this would have increased the thermal margin such that cooling is not needed and another failure mode is avoided. Keep it simple!!
Many thoughtful comments .. and better informed than in most media.
The fact remains..
We are just speculating with limited specific knowledge to the details of the two 787 Dreamliners with damaged batteries. This is a very small sample size to make generalizations with. And, yes, media's love of speculation is likely to hurt the image of anything with Li-ion batteries. And that is unfair.
Old US Air force definition of an airplane:
A group of compromises , flying in close formation.
A couple of issues I have with the overall reporting of this problem... First, everyone discribes the battery as Boeing's design... Having worked in aerospace, this part very likely was subcontracted... That does not relieve Boeing of responsibility, but the Boeing engineers I have worked with are excellent aerospace people, maybe not battery people... Therefore the possible outsourcing...
Second, many have freely tossed around the word 'fire'... related to this failure... I know, many of our parents probably stated "where there is smoke, there is fire!" but in reality there isn't always... It is obvious there was significant heat released, and a great amount of smoke... but maybe not flame... My experience with lithium-ion batteries leads me to believe there quite possibly was not flame generated... The batteries have high energy density but unlike gasoline, I have not experienced flame or explosion as a result of failure...
Recent publications on Li batteries indicate that Li-ion batteries have a problem which NiCads do not: The former melt at a very low temperature and once the process starts, it doesn't end until the battery is consumed in a catastrophic meltdown, thus the fires. NiCads, however, require double the weight for the same energy storage, thus the urge to use Li's.
One can readilly extrapolate that the new Li's used on the aircraft are larger than previous models, thus quite possibly creating a temperature gradient from the innermost cells to the outside which is risky in terms of reaching the melting point within the battery. If this be true, two cures are indicated: (1) active cooling of the batteries (not currently provided for in the Boeing design), including possibly active cooling within the battery volume, and temperture sensing within the battery (also apparently not included) as a control signal to the charging circuitry.
Battery powered cars are a product of the man-made global warming theory and taxpayer subsidies. If one believes in the theory, then one should be prepared to have egg on one's face when the theory is finally accepted as a hoax. Quiz: Who was it that said back in 1933 that "if you tell a lie and keep repeating it, the lie will come to be accepted as the truth ... the truth is the mortal enemy of the lie and thus, by extention, the truth is the mortal enemy of the state"? Hint: der Fuerher loved this guy.
My quip that had Bob Lutz been the President of Boeing this would never have happened, besides being on point and a bit humerous bears some powerful truth.
The engineer of the powertrain of the Volt and the watered down ELR is a woman. That there is a cooling system for the batteries surely owes some credit to her.
When Bill Stout was killed and Henry decided to walk away from the aircraft industry in which he was the leader, the aeronautical engineers, full of pride of superority, left Detroit for the west Coast.
Looks to me like the Engineers of Detroit are not that inferior at all when it comes to hard core thinking, but they went a long way towards hurting the Converj by abusing the absolutely superior work of the designers.
I'm using the term to indicate Designers who went to Design School and studied Design.
The headline is a most unfortunate, dangerous twist. Don't forget that the Volt is outselling the Corvette and is a magnificent vehicle.
Perhaps Elon could tell us about his cooling system and his safety ratings in a side impact.
Chuck, it is a wonder that the engineers at Boeing do not seem to have provided enough battery protection, or cooling, is puzzling. It is puzzling on a couple of levels. The first is that Boeing is an aerospace company, and that kind of thing is very important in that world. The second is tha they do not seem to be up on the latest research. Any reading of the information available from vendors of CAE software, such as Ansys and Comsol, would reveal lots of articles about lithium ion battery research from the major auto companies. One of the recurrent issues is cooling.
Don't forget, though, that there was that case of the Chevy Volt that had been used in a crash test caught fire after sitting there for a couple of weeks, if I recall correctly. You wrote an article mentioning it just about one year ago. And, of course, there is the celebrated case of the Apple laptop batteries that caught fire. These are power sources that are very good, but do requre, as many of your readers point out, some very good engineering to use safely. I use one in my laptop and I am now comfortable using it in my lap. That, in itself, says something.
I agree with George--there is the factor that Boeing was going to take lumps on this thing, and there will probably be more lumps to come. Surely they knew that, and they will get past this. In the meantime, while it should not be surprising the non-technical press gets it wrong or jumps to conclusions to sell airtime or imprints, we should expect more from the engineering community. What amazes me is that with no analytical results so far (a lot of experts working for weeks) we have so many comments on DN and elsewhere condeming, convicting, villifying, etc. Boeing engineers and/or management. Now who's rushing to judgment?
Regarding the article, I agree with the author in the sense that this is not an apples to apples situation, so we should not go on an automotive witch hunt. Yet, given the tiny penetration and production of EVs to date, I would expect more issues with them in the future. Let's face it, the Automotive industry continues to make mistakes after more decades of experience than the Aviation industry. Bad tire designs, bad suspension designs, bad electronics, bad material choices (remember all the peeling paint when plastic bumper parts came out?), you name it. What do all these have in common? Not enough testing. Or ignoring results. Or poorly designed tests, which is amazing for such a mature industry as Automotive.
So while I prefer not to crucify Boeing, let's not anoint the Automotive Industry with sainthood just yet.
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