Jump to content

23 posts in this topic

Posted

[color=#333333][font=Arial]The lithium ion batteries installed on the Boeing 787 are inherently unsafe, says Elon Musk, founder of SpaceX and owner of electric car maker Tesla.[/font][/color] [color=#333333][font=Arial]"Unfortunately, the pack architecture supplied to Boeing is inherently unsafe," writes Musk in an email to Flightglobal.[/font][/color] [color=#333333][font=Arial]"Large cells without enough space between them to isolate against the cell-to-cell thermal domino effect means it is simply a matter of time before there are more incidents of this nature," he adds.[/font][/color] [color=#333333][font=Arial]Both Boeing and Tesla use batteries fueled by lithium cobalt oxide, which is among the most energy-dense and flammable chemistries of lithium-ion batteries on the market. While Boeing elected to use a battery with a grouping of eight large cells, Tesla's batteries contain thousands of smaller cells that are independently separated to prevent fire in a single cell from harming the surrounding ones.[/font][/color]
[color=#333333][font=Arial]"Moreover, when thermal runaway occurs with a big cell, a proportionately larger amount of energy is released and it is very difficult to prevent that energy from then heating up the neighboring cells and causing a domino effect that results in the entire pack catching fire," says Musk.[/font][/color]

[color=#333333][font=Arial]An aerospace-capable version of Tesla's battery has been developed for use in SpaceX's Falcon 9 space launch vehicle. SpaceX, also owned by Musk, competes with Boeing/Lockheed Martin joint venture United Launch Alliance for customers. Boeing has thus far declined offers of assistance from Tesla and SpaceX, says Musk.[/font][/color] [color=#333333][font=Arial]"They [Boeing] believe they have this under control, although I think there is a fundamental safety issue with the architecture of a pack with large cells," writes Musk in an email. "It is much harder to maintain an even temperature in a large cell, as the distance from the center of the cell to the edge is much greater, which increases the risk of thermal runaway."[/font][/color]

[color=#333333][font=Arial][size=1][img]http://www.flightglobal.com/Assets/GetAsset.aspx?ItemID=49241[/img][/size][/font][/color]



[size=4][color=#333333][font=Arial]Musk's assessments of battery cells were confirmed by Donald Sadoway, a professor of electrical engineering at the Massachusetts Institute of Technology.[/font][/color] [color=#333333][font=Arial]"I would have used the same words," says Sadoway. "I would have used the same words. I'm glad someone with such a big reputation put it on the line."[/font][/color] [color=#333333][font=Arial]"He's engineered [Tesla's battery] to prevent the domino effect, while Boeing evidently doesn't have that engineering," adds Sadoway.[/font][/color] [color=#333333][font=Arial]As a fleet-wide grounding enters its third week, the battery failures on 787s flown by Japan Airlines and All Nippon Airways eariler this month remain under investigation by the US National Transportation Safety Board. Japanese inspectors have cleared the maker of the battery, GS Yuasa, of any defects before the unit leaves the factory. But both Japanese and US investigators continue to examine and test the batteries to understand why they failed after they were integrated into the 787 electrical system and operated on commercial flights.[/font][/color][/size]

[size=4][color=#333333][font=Arial]The NTSB, for example, has began a detailed examination of an undamaged 787 battery at a US Navy laboratory, hoping to "uncover signs of any degradation in expected performance".[/font][/color]
[color=#333333][font=Arial]Investigators are trying to find the answer to a problem that eluded Boeing and the FAA in the certification phase, even though the manufacturer and the regulator were well aware of the risks posed by lithium-ion batteries.[/font][/color]
[color=#333333][font=Arial]Mike Sinnett, Boeing's 787 chief project engineer, explained the careful design philosophy employed for the 787's battery system, the first to serve as a starter for an auxiliary power unit and emergency power back-up in a commercial aircraft.[/font][/color] [color=#333333][font=Arial]"I design a cell to not fail and then assume it will and the ask the next 'what-if' questions," Sinnett said. "And then I design the batteries that if there is a failure of one cell it won't propagate to another. And then I assume that I am wrong and that it will propagate to antoher and then I design the enclosure and the redundancy of the equipment to assume that all the cells are involved and the airplane needs to be able to play through that."[/font][/color][/size]

[size=4][color=#333333][font=Arial][url="http://lightglobal.com/news/articles/elon-musk-boeing-787-battery-fundamentally-unsafe-381627/"]http://www.flightglobal.com/news/articles/elon-musk-boeing-787-battery-fundamentally-unsafe-381627/[/url][/font][/color][/size]

Share this post


Link to post
Share on other sites

Posted

Oddly enough, the Japanese claim there's nothing wrong with the battery (which just so happens to be designed in Japan).

[quote]Dreamliner: No fault found with Boeing 787 battery

Airline safety inspectors have found no faults with the battery used on Boeing's 787 Dreamliner, Japan's transport ministry has said.

The battery was initially considered the likely source of problems on 787s owned by two Japanese airlines.

It has raised fears that there will be no quick fix to a problem that meant all 50 787s in service were grounded.

Attention has now shifted to the electrical system that monitors battery voltage, charging and temperature.

Transport ministry official Shigeru Takano said "we have found no major quality or technical problem" with the lithium-ion batteries. Shares in GS Yuasa, which makes the batteries, jumped 5% on the news.

"We are looking into affiliated parts makers," he said. "We are looking into possibilities."

The safety investigation started after one of the 787s operated by All Nippon Airways made an emergency landing in Japan when its main battery overheated. Earlier, a battery in a Japan Airlines 787 caught fire while parked at Boston's Logan International Airport.

Zafar Khan, aviation analyst at Societe Generale, said: "The obvious implication is that it may prolong the grounding.

"If it's not the battery then we are back to the drawing board. We know it's an electrical - and not a structural - issue and that will be the focus for the inspectors. But there's a lot of cabling on these aircraft."

[b]'Fingers crossed'[/b]

Keith Hayward, head of research at the Royal Aeronautical Society, said that if the issue is no longer about replacing a faulty battery, it raised the prospect of Boeing having to do a major re-design.

"I think people had their fingers crossed that it was a battery fault... it looks more systemic and serious to me. I suspect it could be difficult to identify the cause," he said.

He added that aviation regulators will have to put the 787 through another airworthiness certification process, which itself could become a complicated and lengthy process depending on the final cause of the problem.

Two weeks ago the US Federal Aviation Administration said both batteries had leaked electrolyte fluid, and there had been smoke damage to parts of the aircraft.

The FAA said airlines must demonstrate battery safety before flights could resume, a statement that effectively meant airlines had to ground their 787s.

Boeing, which competes against Europe's Airbus, has halted 787 deliveries. Boeing has orders for more than 800 Dreamliners.

The 787 is the first airliner made mostly from lightweight composite materials, which increases an aircrafts fuel efficiency. It also relies on electronic systems rather than hydraulic or mechanical systems to a greater degree than any other airliner.

[b]Compensation[/b]

Mr Khan said that most analysts had forecast that the 787 would be out of service for, perhaps, eight weeks at most. Beyond 10-12 weeks, and it could impact on Boeing's production line and future deliveries, he said.

"That raises questions of damages (to airlines) for late delivery and the leasing of alternative aircraft," he said.

Last week, analysts at Bernstein put the cost of fixing the Dreamliner at about $350m (
2 people like this

Share this post


Link to post
Share on other sites

Posted

Its a shame this. The 787 is probably one of the safest flying machines around, yet due to efficiency and space, the lithium cell may just be its downfall. Fearsome in everyday use, such as laptops, mobiles etc, but 'deadly' as part of today's commercial flying.
1 person likes this

Share this post


Link to post
Share on other sites

Posted

The use of smaller, physically isolated LiIon cells is one of Tesla & SpaceX's better ideas. They set the cell size to a tad larger than a AA battery, limiting the amount of energy in a failed cell that needs to be dissipated. Other battery makers use much larger prismatic or cylindrical cells that would generate tons more heat if they fail. Individual cells can also be electrically isolated from the rest of the stack if a problem is detected. Tesla's cells are fabbed by Panasonic to their specs.
1 person likes this

Share this post


Link to post
Share on other sites

Posted

soo...why isn't boeing going to tesla for help?

Share this post


Link to post
Share on other sites

Posted

[quote name='-Razorfold' timestamp='1359514615' post='595489194']
Oddly enough, the Japanese claim there's nothing wrong with the battery (which just so happens to be designed in Japan).



Source: [url="http://www.bbc.co.uk/news/business-21230940"]http://www.bbc.co.uk...siness-21230940[/url]
[/quote]

This was my understanding too. I had read that it was the charging mechanism that was bad, not the batteries themselves.

Share this post


Link to post
Share on other sites

Posted

Late reports are that it was the electrinics / wiring, but Musk is still correct that the battery design is suboptimal.

Share this post


Link to post
Share on other sites

Posted

[quote name='DocM' timestamp='1359591123' post='595491112']
Late reports are that it was the electrinics / wiring, but Musk is still correct that the battery design is suboptimal.
[/quote]
Of course it is. The same **** happened when GS Yuasa tested the 787 batteries a couple of years ago and it looks like they didn't change anything from it.

Not to mention, the outsourcing done on the 787 is crazy.

This battery was contracted to be designed and built in Japan. Instead what happened was the battery was designed in Japan, manufactured in China and then shipped to France (Thales Communications) where it was put together and had some bits added on before being sent to Boeing.

The wing ribs were originally going to be made in Japan but that company sold the contract to Hyundai who sold it to a Chinese company.

Share this post


Link to post
Share on other sites

Posted

I've never been a fan of lithium batteries. They should have used something else.

Share this post


Link to post
Share on other sites

Posted

Lithium ion is the best for the job [b]if you build them properly[/b], meaning lots of small, well isolated cells. Smaller isolated cells limit the amount of heat generated by a shorted cell.

This is how Tesla builds its batteries, which other automakers also use, and it's how SpaceX builds its batteries for the Dragon spacecraft and its Falcon rockets.

JAL 787 cause: shorted battery cell

http://arstechnica.com/business/2013/02/investigation-reveals-cause-of-battery-fire-on-boeing-787-dreamliner/

Note to Boeing: call Elon

[quote]>

Now, investigators at the National Transportation Safety Board have determined the cause of the battery fire in the Japan Airlines 787, saying that the fire was caused by a short circuit in one of the battery

Share this post


Link to post
Share on other sites

Posted

^What's funny about this whole thing:

Japan's transport safety board said a whole two days after the grounding that there was nothing wrong with the batteries and they were fine. And now the NTSB says the batteries do have flaws. Not to mention that this same issue happened in 2007 during testing with the same batteries that GS Yuasa then dumped into the 787. Trying to protect Japanese companies eh JTSB?

Another story in the 787's saga, apparently the FAA contracted out 90% of the safety / certification stuff to Boeing in order to save costs. So in essence Boeing engineers were the ones vouching for the safety of the plane.

In comparison, say you built your own kit airplane and wanted to get it certified. You'd call up the FAA and an inspector will come over to check it. This is for a tiny plane that can't be used for hire (and has a bunch of other restrictions too).

[quote]The tests on the lithium-ion batteries at the center of Boeing

Share this post


Link to post
Share on other sites

Posted

FAA dumped it to Boeing, and odds are Boeing largely deferred to GS Yuasa & Japanese regulators. Distributed responsibility = circle jerk IMO.

Meanwhile, SpaceX & Tesla engineers took on the responsibility themselves; making their own judgements based on rational self-interest, which appear to be very sound, speccing to Panasonic [b]exactly[/b] what they wanted. They are now not only driving the roads with them but flying them in the harshest environments of all - space launches & flight.

There's a lesson in there somewhere....

Tesla Model S battery

[img]http://i.i.com.com/cnwk.1d/i/tim/2010/10/06/ModelS_pack01.jpg[/img]

Share this post


Link to post
Share on other sites

Posted

A picture of the 787 battery:

[img]http://i.imgur.com/9mnEmxm.jpg[/img]

Share this post


Link to post
Share on other sites

Posted

[quote name='-Razorfold' timestamp='1359514615' post='595489194']
Oddly enough, the Japanese claim there's nothing wrong with the battery (which just so happens to be designed in Japan).
[/quote]

Obviously someone is wrong.

Share this post


Link to post
Share on other sites

Posted

[quote name='Growled' timestamp='1360802226' post='595520326']

Obviously someone is wrong.[/quote]

And that someone isn't on this side of the Pacific. They are obviously in full CYA mode.

Share this post


Link to post
Share on other sites

Posted

Uh-Oh....

http://aviationweek.com/Article.aspx?id=/article-xml/awx_02_19_2013_p0-550136.xml

[quote][b]Swelling Found In Second Battery On All Nippon 787[/b]

Cells in a second lithium-ion battery on a Boeing Co 787 Dreamliner forced to make an emergency landing in Japan last month showed slight swelling, a Japan Transport Safety Board (JTSB) official said on Tuesday.

The jet, flown by All Nippon Airways Co, was forced to make the landing after its main battery failed.

Share this post


Link to post
Share on other sites

Posted

O_o

Article on "the fix":http://www.aviationweek.com/awmobile/Article.aspx?id=/article-xml/awx_02_20_2013_p0-551029.xml

http://www.aviationweek.com/awmobile/Article.aspx?id=/article-xml/awx_02_20_2013_p0-550650.xml

[quote][b]Boeing To Present 787 Fix Proposal To FAA[/b]

A Boeing team led by Commercial Airplanes President Ray Conner is set to present details of its proposed near-term solution to the 787 battery issues to the FAA later this week, possibly as early as Feb. 21.

According to airline sources, Conner will present details of the manufacturers

Share this post


Link to post
Share on other sites

Posted

Getting a bit close the A350 for these issues now Boeing.

I fear for our QANTAS. They were ****ed around with the 380 and it cost them, not they'll be ****ed around with the 787. They are going to have to continue flying their old heaps of **** 767 fleet.

Share this post


Link to post
Share on other sites

Posted

I like how one of Boeing's solutions is "put a box around the batteries so any explosion can be contained"

Wtf Boeing...wtf.

[quote]Boeing is to meet with the Federal Aviation Authority (FAA) tomorrow to discuss temporary methods to fix the problems with the 787's auxiliary power unit, it has been reported.

According to the Associated Press, Boeing Commercial Airplanes' CEO, Ray Conner, is to meet with Michael Huerta, head of the FAA. They will discuss adding more ceramic spacers between battery cells, which Boeing believes will contain any potential fire caused by short-circuiting.

[b]Another solution is to encase the cells in a titanium or steel box equipped with a high-pressure vent to contain and expel any fire.[/b]

However, yet more confusion was shed on the cause of the fire yesterday when Japan's Transport Ministry disclosed that the auxiliary power unit it examined was improperly wired.

Investigators at the National Transportation Safety Board (NTSB) had already found a different issue. It discovered multiple short-circuiting of eight cells, which caused progressively hotter temperatures, known as a 'thermal runway'.

Without complete understanding of the cause, a long-term solution is still far from sight. Meanwhile, Boeing is incurring significant costs and 787s are reportedly piling up as its production plant.

Last week, Imperial Capital analyst, Ken Herbert, estimated it could cost Boeing $25m a month in direct costs. Air India will now be seeking compensation for the delayed delivery of its 787s and United Airlines has announced that it has scheduled for its 787s to be out of action until at least the beginning of April.[/quote]

Source: http://afm.aero/news/talking-point/item/583-talking-point-boeing-to-suggest-quick-fix-for-787

Share this post


Link to post
Share on other sites

Posted

I don't think Musk is in a position to categorically say that the 787 battery is fundamentally flawed. Li-Ion batteries are inherently dangerous but can be done safely, as is the case in our phones.

I'm not an aeronautical engineer and even if I were I haven't studied the confidential plans for the Boeing like the FAA and other safety boards have. One thing for sure is that Boeing has every incentive to make the plane as safe as possible. AirBus is closing in on them in a very hardcore manner and planes that are known for dangerous conditions won't get them more orders. So, if the battery is flawed I'm sure they'll replace the design otherwise, the problem most likely lies elsewhere.

Share this post


Link to post
Share on other sites

Posted

[quote]So, if the battery is flawed I'm sure they'll replace the design otherwise, the problem most likely lies elsewhere. [/quote]
I dunno. When GS Yuasa tested the batteries back in 2007 the same problem showed up, but they still put them on the 787.

The FAA contracting out 90% of the safety tests / checks to Boeing to sign off on probably didn't help either.

Share this post


Link to post
Share on other sites

Posted

[quote]Without complete understanding of the cause, a long-term solution is still far from sight. Meanwhile, Boeing is incurring significant costs and 787s are reportedly piling up as its production plant.[/quote]

I can't feel that sorry for them. They should have analysed the risks going in.

Share this post


Link to post
Share on other sites

Posted

[quote name='LogicalApex' timestamp='1361497369' post='595535844']
I don't think Musk is in a position to categorically say that the 787 battery is fundamentally flawed. Li-Ion batteries are inherently dangerous but can be done safely, as is the case in our phones.
>[/quote]

It's a difference in risk mitigation.

What Musk is challenging is the use of large, high volume cells with poor to middling physical and electrical isolation. Each large cell stores more energy, so if/when it fails more heat is released by a larger volume of material, which is also harder to contain.

OTOH, the Panasonic near-AA size cells Tesla & SpaceX use are more easily isolated and release less total heat if/when they fail. This all reduces the risk to other cells and the battery as a whole.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0

  • Recently Browsing   0 members

    No registered users viewing this page.