Aviation experts said the energetic quality of lithium-ion can be a concern onboard aircraft. "One of the issues with lithium batteries is they get very hot," Freiwald said. "When they ignite, they can burn so hot that Halon 1301 won't extinguish a fire."
Automakers, many of whom use lithium-ion chemistries in hybrids and electric cars, typically operate their batteries with cooling systems. The Chevy Volt, for example, employs a fluid coolant that circulates through 1mm thick channels machined into 144 metal plates sitting between the battery's cells. Other automakers have employed air cooling on hybrids.
Even with cooling, however, lithium-ion automotive batteries have been known to have problems on rare occasions. In 2011, a fire started in a Chevy Volt weeks after government crash testing, causing a ripple of concern. "The chemistry is edgy," Donald Sadoway of MIT wrote in an email to Design News after the incident. "The electrolyte is an organic fluid that is flammable, highly volatile at even moderately elevated temperature and in the presence of metallic lithium, which can form on the negative electrode at high charging rates."
Although it's not known whether the Dreamliner employs battery cooling systems, its batteries are smaller than those of plug-in hybrid cars. A National Transportation Board (NTSB) examination of an auxiliary power battery unit from the JAL Boeing 787 that caught fire in Boston's Logan Airport on January 7 showed that it measures 19 inches x 13 inches x 10 inches and weighs just 63 pounds. In contrast, electric vehicle batteries can weigh more than 400 pounds.
Freiwald said he doubts the two reported fuel leaks are related to the overheating incidents. Those were more likely to have been caused by human error, he said.
Experts who spoke with Design News emphasized that the cause of the problems isn't fully understood yet, and that such incidents need to be put into perspective. "None of these were catastrophic failures," Dietz told us. "The engineering systems provided an alert to the failures and action was taken. There should be some solace in that."
SystemsGuy, my understanding is that this battery came into play only on the ground, i.e. something to do with landing gear controls or something. So high altitude cold air doesn't help that situation much.
In any case, flight controls probably get their biggest workout getting to altitude or landing, all lower altitude issues, and must be designed for the worst case.
Overcharging is well known to cause overheating. The charging system and overheating protection system need to wwork to prevent this. Apparently this has not been completely effective. I would look carefully at the charging system to see what unusual conditions may exist. Perhaps the intense cold in the exterior environment could trick the charging system into overcharging.
I find it ironic that the 787 uses high capacity Lithium Ion batteries for its standby/startup power when such batteries onboard as cargo have had severe restrictions placed upon them in the past. For example UPS considers batteries with a watt/hour capacity greater than 20 but less than 100 to be shippable but only when handled as hazardous material. Anything above 100 Wh is not shippable by air according to UPS. This for a disconnected, not in service battery!
The IATA bans cargo shipments of primary cell Lithium Metal batteries from all passenger planes. Obviously, the button cell in your wristwatch is okay as long as it isn't part of a cargo shipment.
The IATA regulation of 100 Wh or less for secondary Lithium Ion batteries has been the limiting factor for available run time for professional video cameras.
At first all the failures may look unrelated due to the fact they all perform different functions on the Airbus.
But before a general comment can be made as in the article, as an engineer, I would investigate the specifications requirements from all these peice parts and check in- fact they have been enviromentaly accepted for high altitude low atmospheric pressure, Vibration of jet engine frequency and air turbulance of sympathetic oscillations, and extreme temperature changes mostly cold temps.
Now if we take all these into effects, I bet we might find a common thread. It cost $$$ for screens like this and BOEING could have cut cost by using "COTS" of the shelf items.
The Lithium batteries were once not allowed on board plane in laptops because of inherient design issues that caused a possible fire. What has changed with Lithium batteries to make them safe???
Someone in BOEING is an Engineer of poor judgement....Not the structure of the aircraft but selected components not purchased properly for the job is whats at fault.
I bought a Cadillac and the dealer gives me a Chevrolet...get my point
How often we recommend that you always make one change at a a time in anything new. Boeing changed so many things at once it is remarkable the plane flew at all! I'm a big Boeing fan, but me thinks your bite was too big for thy mouth...
It's difficult to find what the fault is on a problem like this. These projects have extensive testing (i am an aviation test engineer). It could have been many things that lead to this issue. (Might not even be related with the battery at all). It's a very large system with many components and the battery is the weak link. I am confident that FAA and Boeing will find a solution and this plane will fly again. Let's not jump to conclusions and let's wait on an official announcement from FAA or Boeing.
I am not associated with FAA or Boeing. It's a marvel that these metal birds can fly. This happens all thanks to companies like Boeing.
Paul, even with the extremely greedy industry attitude nowadays, I doubt Boeing purchased such kind of batteries. Aviation is characterized by very high standards, but in these days, some goofes can (and doo pass).
For me it is another (of the many) cases of bad results derived from the abuse of that "modern" practice of outsourcing. Not that outsourcing per-se is bad, but the ever growing tendency of completely relying on subcontractors (that sense of "lets the supplier take care of this and forget" attitude that has its roots in so called modern administration practices, that permeate companies previously known for their reliable products.
Trying to push out a completely new design, that has many advances at the same time requires a proportionately larger and more trained workforce, so the MBA geniuses at top level decide to place an often too large share of design, integration and testing on outside subcontractors, and in theory, they instantly kill any problems! This is a world-wide tendency courtesy of latter generations of so called 'professionals' that appear to have all the credentials that (apparently), qualify them as experts. As older generations of old-fashioned engineers retire, the new ones arrive to the scene looking as disproportionately capable ones, that rely too much on software aids, simplified methods and a generalized lack of true hands-on real life experience. I seriously doubt how many of those engineers have actually seen a small Lithium battery pack as it catches fire? (One of my hobbies is Model Airplane building and flying, and there are some high temperature ceramic pots sold in the hobby market, designed precisely to contain those relatively small batt packs if they decide to ignite under charge -or storage-, for that matter!).
Regarding the general attitude towards too much confidence or reliance in a given supplier, certifying body or industry in general, I'll give you an example:
I read about two weeks ago: Daimler and Volkswagen decided to defy the European Union Jan. 1 deadline that orders the use of a new, 'ecologically friendly' refrigerant that should replace the widely used R134a, owing to the results of realistic automobile crash test performed in houseby Daimler engineers, that resulted in fires, even when the DuPont-Honeywell new refrigerant has been enthusiastically promoted as a "safe" and much more "green" substitute for R134a. The fact is that the same companies have promoted the new product as "only slightly flammable" (if such term is plausible). the exact phrase said "It is well known that HFO-1234yf is a mildly flammable refrigerant," [Diane Iuliano Picho, global business manager, Opteon™ refrigerants.]
The good guys at GM quickly jumped on the bandwagon and publicly announced they swear at the product and will happily use it!
This shows that industry, suppliers, and even governmental testing bodies, all can be persuaded in a given moment to favor (or allow) the use of a new product, as it represents "innovation" (DuPont's Terrence Hahn reportedly said: "The key element for the EU government is forcing the implementation of their rule," said Terrence Hahn, general manager of the U.S. company's fluorine products unit. "If you are not doing that, you are going to severely dampen innovation..."
In the B-787 case, over relying on the supplier for the battery system for everything, is like relying on the publicity published by the freon replacement manufacturer in order to declare the system "safe". In the refrigerant case, it is curious that the Daimler engineers were able to produce a crash fire when several others weren't. I applaud them, and applaud both Daimler and Volkswagen for defying the dumb politicians of the EU, the same people that gave us the ban on leaded solder and other measures that fit well the "Law of uninntended consequences".
It is not difficult to perform an illustrating experiment: take a little cooking oil, placed into a cup it is hadly flammable, but put into an old parfume sprayer, press the rubber bulb and the same oil ignites with incredible violence. I doubt some self appointed experts have actually performed this simple experiment. No amount of wishful thinking or babying will bend the laws of physics (or chemistry). There is no substitute for experience. Amclaussen.
Absolutely! but sometimes people, not withstanding how competent or well trained, perform incredibly simple (as an after though) errors. All aeronautical companies do, from time to time, execute some grave ones. Remember the control valve on the Rudder Control Unit of the B-737... Or the software glitches of the A-320... or the uncommmanded thrust reverser openings on the Fokker-100. In a large number of these catastrophic failures there is an identifiable dose of incomplete testing. The Wright Brothers were 1) very knowledgeable and, 2) fully committed to testing, so that they were able to survive for quite a few years. Blind faith or 'confidence' should not be in the vocabulary of an aviation expert, my two cents. Amclaussen.
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