Jan 22

Boeing 787 Battery Fire Update

 

By George S. Bower

We all know that the batteries involved in the Boeing 787 fires are lithium-ion batteries like in the Volt.

But:

How big is the battery?

Is it liquid cooled?

Where and what is the battery management system?

What is the battery chemistry?

Who makes the cells and what are the cell specs?

And of course:

What was the cause of the fires?
 

Fig 1
 

We can see from figure 1 that the battery has 8 cells. Also we can see some circuit boards in the battery case that are presumably the battery management system.
 

fig 2
 

The cells are produced by Yuasa. Yuasa cell specs are shown in figure 2 along with some calculated specs for the pack in total.
 

fig 3
 

The battery box is APPROXIMATELY 11 inches wide by 10 inches tall by 14 inches long and has a stored energy of 1.9kwh. There appears to be no liquid cooling in the battery.

Yuasa cells are a different chemistry than the Volts cells. Yuasa cells are LiCoO2while Volt cells areLiMn2O4. The Yuasa cells are high energy density cells as we might expect in aircraft in order to minimize weight. The Yuasa cells also tend to have a higher combustion rate that the Volts. The CoO2 cell chemistry was used in the Tesla roadster.
 

Avianca_787-8_inflt_med
 

Charles Whalen:

“LiMn2O4 [Nissan LEAF / GM Volt] reaches a peak combustion rate of 2.5C/min, while LiFePO4 reaches a peak combustion rate of 3.4C/min. Contrast those to the combustion rates of the batteries that Tesla uses — in the Roadster, LiCoO2 reaches a peak combustion rate of 360C/min, and in the Model S, LiNi.8Co.15Al.05O2 reaches a peak combustion rate of 280C/min…”

Latest Developments

Safety Board Rules Out a Cause for 787 Battery Fire

“Federal investigations said Sunday that they had ruled out excessive voltage as the cause of a battery fire on a Boeing 787 in Boston this month, widening the mystery into what led to the grounding of the world’s most technologically advanced jet after a second battery-related problem last week.
With investigators focused on the plane’s lithium-ion batteries, the National Transportation Safety Board said an examination of the data from the plane’s flight recorder indicated that the battery “did not exceed the designed voltage of 32 volts.”

So as of this point in time we don’t know the cause of the fires. We can only speculate.

What we do know is:

There are a lot of tired engineers sleeping on cots at Boeing.

Sources:
New York Times
Green Car Reports
Green Car Congress
GS Yuasa
Charles Whalen via GM-Volt

This entry was posted on Tuesday, January 22nd, 2013 at 5:55 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

COMMENTS: 54


  1. 1
    Dave G

    +9

     

    Vote -1 Vote +1

    Dave G
     Says

     

    Jan 22nd, 2013 (6:28 am)

    Great article. As we started finding out in 2007, not all Li/Ion chemistries are the same, and the Volt chemistry sacrifices some energy density for safety and longevity.


  2. 2
    James McQuaid

    +19

     

    Vote -1 Vote +1

    James McQuaid
     Says

     

    Jan 22nd, 2013 (6:59 am)

    Great post George! Let’s hope that the unintended consequences of this somehow turn out to be positive.

    If some political boob on the radio was yelling that Boeing was deliberately trying to kill its customers, we’d all recognize how inappropriate, malicious, and unpatriotic such comments were.


  3. 3
    Steve

    +2

     

    Vote -1 Vote +1

    Steve
     Says

     

    Jan 22nd, 2013 (7:22 am)

    Beginning to sound like a vibration/mechanical or battery defect issue. That’s justmy speculation based on very little data, a SWAG at best.


  4. 4
    Nelson

     

    Vote -1 Vote +1

    Nelson
     Says

     

    Jan 22nd, 2013 (8:13 am)

    I hope they’ve analyzed and ruled out any surrounding sources for possible interactions that may cause this type of failure.
    i.e. Battery located near a device that causes the battery to overheat.

    ??
    Do the cells need to be tested at various pressure ratings since it will be used on a plane?
    What happens to the battery if the plane loses pressure where the battery is located?

    NPNS!
    Volt#671


  5. 5
    lousloot

     

    Vote -1 Vote +1

    lousloot
     Says

     

    Jan 22nd, 2013 (8:17 am)

    Lots of news on this, mostly saying the same thing.

    we do not know yet.


  6. 6
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 22nd, 2013 (8:21 am)

    Dave G:
    Great article.As we started finding out in 2007, not all Li/Ion chemistries are the same, and the Volt chemistry sacrifices some energy density for safety and longevity.

    Does anyone have the energy density of the Volt’s cells?? I have a number but I’m not sure how accurate it is. I think I based it on an estimated pouch size (about 3 years ago).
    I have 5X7X.25 for the pouch size
    14.8 ah
    3.75 V
    55.5 wh
    and 388 wh/L


  7. 7
    joe

    +5

     

    Vote -1 Vote +1

    joe
     Says

     

    Jan 22nd, 2013 (8:23 am)

    Maybe it’s time for Boeing to call the GM Volt team for advice. Even “nasaman” could give them advice. It would not hurt anything, but their pride.


  8. 8
    Roy_H

     

    Vote -1 Vote +1

    Roy_H
     Says

     

    Jan 22nd, 2013 (9:04 am)

    It looks like they took the “conservative” approach and used the oldest (most mature) chemistry available. Almost all lithium battery fires I have read about use this chemistry. Over charging has always been the main suspect. 32 volts / eight cells = 4 volts/cell. This is significantly higher than the nominal 3.7 volt rating. If this high voltage was maintained for a long period, I would expect over-heating.


  9. 9
    volt11

    +8

     

    Vote -1 Vote +1

    volt11
     Says

     

    Jan 22nd, 2013 (9:15 am)

    It’s distressing to think that better engineering went into a car, namely the Volt, than a supposedly state-of-the-art commercial airplane.


  10. 10
    Raymondjram

    +7

     

    Vote -1 Vote +1

    Raymondjram
     Says

     

    Jan 22nd, 2013 (9:37 am)

    As an EE, I can offer a quick solution to the heating issue. Most of those who worked with laptops know that the CPU is the component that generate the most heat since it operates at the highest frequency. If you have seen an opened laptop, you will easily see how the manufacturers take care of that heat.

    Taking the ThinkPad laptops as my example (I have repaired many and I presently owe two), IBM installed a small heat sink over the CPU and uses what is called a “heat pipe” between that heat sink and another larger heat sink with a small flat ventilation fan at the edge of the laptop (ThinkPads have it at the left side near the hinges). A heat pipe is a metallic tube (mostly copper) that carries a special coolant which moves by the heat it is conducting. Heat pipes contain no mechanical moving parts and typically require no maintenance. So it is a liquid cooling system, but the heat pipe is sealed, and prevents any leakage inside the laptop. The heat generated by the hot CPU causes the coolant to evaporate into a gas and move toward the fan-cooled heat sink, where the fan blows the heat away, condenses the gas into a liquid, and returns to the CPU. The size of the heat pipe determines how fast the heat is moved out, and can be measured as BTUs per hour. Yes, it is the same as an air conditioner because both are grouped as “heat pumps”. The difference is size and movement. The heat pipe uses the same heat to move the coolant, while large heat pumps use pumps to move the coolant. Read more here:
    http://en.wikipedia.org/wiki/Heat_pipe

    So, what Yuasa and Boeing must do is add a large heat pipe between the Li-ion battery pack and a heat sink on the external frame of the battery box or in the cabin so the excess heat will be conducted to the atmosphere, or to another coolant system inside the cabin. The fan may not be needed, so there are no moving parts.

    See how easy it is fixed?

    Raymond


  11. 11
    MrEnergyCzar

    +1

     

    Vote -1 Vote +1

    MrEnergyCzar
     Says

     

    Jan 22nd, 2013 (10:25 am)

    I’m surprised how small the battery is. There is so much riding on the plane I’m sure they’ll have it figured out soon…. maybe the batteries are just faulty.

    MrEnergyCzar


  12. 12
    Loboc

    +3

     

    Vote -1 Vote +1

    Loboc
     Says

     

    Jan 22nd, 2013 (10:48 am)

    Raymondjram,

    It is only ‘fixed’ if excess heat was the issue. They don’t know the root cause yet.

    Looking at the massive failure (and no external damage outside the containment!), I’m thinking that the battery pack had a meltdown due to design. Not necessarily cell design. They ruled out over voltage at the pack level… We’ll see what the root cause is pretty soon.

    As far as speculation that Volt had more intensive testing, this is pure bs. Aerospace companies are held to a much higher standard than automotive. If a car breaks down, you walk away!


  13. 13
    Loboc

    +1

     

    Vote -1 Vote +1

    Loboc
     Says

     

    Jan 22nd, 2013 (11:14 am)

    Quote from our favorite network:

    “Japanese transportation officials appear to be focusing their investigation more directly on GS Yuasa, which is based in Japan. U.S. investigators appear to be focusing on the entire electrical system and how it interacts with the batteries.”

    http://www.foxnews.com/us/2013/01/22/probe-turns-to-boeing-787s-battery-maker/


  14. 14
    kdawg

    +7

     

    Vote -1 Vote +1

    kdawg
     Says

     

    Jan 22nd, 2013 (11:45 am)

    I think someone in first class plugged in a space heater.

    :)


  15. 15
    Noel Park

    +3

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Jan 22nd, 2013 (12:26 pm)

    joe:
    Maybe it’s time for Boeing to call the GM Volt team for advice. Even “nasaman” could give them advice. It would not hurt anything, but their pride.

    #7

    Yeah, send one over to the GM test lab is my advice. +1


  16. 16
    Noel Park

    +1

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Jan 22nd, 2013 (12:27 pm)

    volt11:
    It’s distressing to think that better engineering went into a car, namely the Volt, than a supposedly state-of-the-art commercial airplane.

    #9

    No kidding. +1

    Advantage – GM.


  17. 17
    Neromanceres

    +3

     

    Vote -1 Vote +1

    Neromanceres
     Says

     

    Jan 22nd, 2013 (12:28 pm)

    kdawg: I think someone in first class plugged in a space heater.

    To my knowledge these batteries are not really used much. The power for the plane comes from generators directly connected to the engines or the jet fuel powered APU (auxiliary power unit). My understanding is the battery acts as a backup to the APU and helps provide electrical energy to start the APU in the event that there is no electrical power. Typical use is when the plane is on the ground and not connected to ground power when the APU is shut off. During normal flight operations the battery isn’t used.


  18. 18
    Sam Jaffe

    +3

     

    Vote -1 Vote +1

    Sam Jaffe
     Says

     

    Jan 22nd, 2013 (12:28 pm)

    RaymondJRam,
    I doubt a heat pipe wouldn work in this application because the thermal mass of heat to be moved is too much for that mechanism. Even a fan wouldn’t work. You also have to ensure that the condensation end of the pipe has sufficiently low temperatures and that might not be the case here. If you need to cool the batteries in an environment like this, you probably have to do some sort of active cooling. And if you have to do active cooling, you’ve already lost the battle: fans and pumps fail too much for an aerospace option.

    Loboc,
    I agree that the most likely cause is in the BMS. LiCoO2 cells rarely fail by themselves–they’re pushed to failure by a malfunctioning BMS that overstresses them. The biggest mistake that Boeing made is they chose laptop cell chemistry to put in their plane. They obviously did it to save weight–they probably saved about 20 lbs by choosing that over LiFePO. But if they had a better decision-making process, then they would have saved billions of dollars in lost sales and groundings by choosing a safer, heavier chemistry.

    One other possibility is that this was an actual physical fire, and not a current-caused fire. If the GS Yuasa cells were penetrated and the resulting leakage came into contact with water, it would start a smoldering fire which would slowly burn through the inside of the pack, causing a lot of smoke. It would also never reach enough heat to damage the metal enclosure. Maybe something is causing (altitude change?) the cell canisters to rupture?


  19. 19
    Noel Park

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Jan 22nd, 2013 (12:32 pm)

    Loboc: As far as speculation that Volt had more intensive testing, this is pure bs. Aerospace companies are held to a much higher standard than automotive. If a car breaks down, you walk away!

    #12

    Well I would have thought so too, but in this case the facts seem to indicate otherwise. Maybe Boeing should call in Raymond in addition to GM. The nasaman idea wouldn’t hurt either.


  20. 20
    Noel Park

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Jan 22nd, 2013 (12:34 pm)

    kdawg:
    I think someone in first class plugged in a space heater.

    #14

    LOL. +1

    Reminds me of all of those posts here about using plug in 12v cabin heaters in Volts. Careful boys and girls!


  21. 21
    DonC

    +2

     

    Vote -1 Vote +1

    DonC
     Says

     

    Jan 22nd, 2013 (12:36 pm)

    In retrospect it wasn’t that smart to use the lithium cobalt cells. They have great energy density but they pose the greatest safety risk. Saving a few pounds on an aircraft just doesn’t seem worth the risk to me. You noted they were used in the Tesla Roadster but they’re also used in all those laptop batteries. You know, the batteries that have caught fire so many times.

    I would have gone with the LiPo chemistry used in cells like those sold by A123. They are very safe.

    Having said this it may turn out that the battery is not directly involved in the cause. So far I think they’ve ruled out the battery and the charger. Not sure what that leaves. LOL


  22. 22
    Noel Park

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Jan 22nd, 2013 (12:36 pm)

    Neromanceres: To my knowledge these batteries are not really used much.

    #17

    Can that little thing possibly be the only battery in that big airplane? Are there more of the same and/or another bigger one somewhere? I wonder what part of the plane’s systems was powered by this one?


  23. 23
    Noel Park

    +2

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Jan 22nd, 2013 (12:45 pm)

    George,

    Thanks for this. VERY thought provoking.

    That’s great photo of the plane in the Avianca livery. Little do I know about aerospace engineering, but it begs the question as to whether the beautiful curvature of the wings is built in or if they assume that shape by deflecting as they pick up the weight of the aircraft. It really looks like a bird in a way. Spectacular!

    I can almost forgive Boeing this silly battery kerfuffle, and all of the other delays and controversies, when I see that unbelievably graceful bit of design.


  24. 24
    DavidV

    +2

     

    Vote -1 Vote +1

    DavidV
     Says

     

    Jan 22nd, 2013 (12:55 pm)

    Roy_H,

    This battery chemistry may be nominal 3.7V, but the max charge is 4.2V. 4.0V is not too high, and would not cause overheating. One likely problem that I haven’t heard mentioned (but I’m sure the engineers are considering) is that the cells may have been discharged too far, and then re-charged. If this happens, even charging to a normal level can cause a fire.


  25. 25
    kdawg

     

    Vote -1 Vote +1

    kdawg
     Says

     

    Jan 22nd, 2013 (1:03 pm)

    Neromanceres: To my knowledge these batteries are not really used much. The power for the plane comes from generators directly connected to the engines or the jet fuel powered APU (auxiliary power unit). My understanding is the battery acts as a backup to the APU and helps provide electrical energy to start the APU in the event that there is no electrical power. Typical use is when the plane is on the ground and not connected to ground power when the APU is shut off. During normal flight operations the battery isn’t used.

    You’re probably right. Most likely it was someone playing Angry Birds during take-off.


  26. 26
    kdawg

     

    Vote -1 Vote +1

    kdawg
     Says

     

    Jan 22nd, 2013 (1:06 pm)

    volt11: It’s distressing to think that better engineering went into a car, namely the Volt, than a supposedly state-of-the-art commercial airplane.

    Didn’t GM say the Volt has more lines of code than a fighter jet?


  27. 27
    George S. Bower

    +1

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 22nd, 2013 (1:12 pm)

    Noel Park: #17

    Can that little thing possibly be the only battery in that big airplane?Are there more of the same and/or another bigger one somewhere?I wonder what part of the plane’s systems was powered by this one?

    Noel,
    I believe there are 2 of these batteries on the plane. One in the front to provide cockpit instrumentation/ displays and one in the back for starting the APU. However, in normal mode power is provided by 2 starter generators on each main engine. There are also 2 starter generators on the APU.

    Each of these starter generators is rated at 250 KVA (KW). So one main engine and it’s 2 starter generators provide 1000 Kw of electrical power. That is 1341 HP so it’s easy to see how much electricity this plane consumes. I believe this airplane since it is all electric uses almost 4 time as much electric as the 777.

    It is an all new design. There is not one other aircraft in the world that uses this all electric design. All other aircraft use pneumatic air to provide power.

    The planes all electric architecture is discussed here:http://gm-volt.com/2012/03/30/the-all-electric-boeing-787/


  28. 28
    George S. Bower

    +1

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 22nd, 2013 (1:23 pm)

    DonC:
    In retrospect it wasn’t that smart to use the lithium cobalt cells. They have great energy density but they pose the greatest safety risk.

    The odd thing is that the data I have shows that the Volts batteries have an energy density of 388 wh/l which is actually MORE energy dense than these batteries which are spec’d at 232 wh/l.

    see #6 above.


  29. 29
    George S. Bower

    +1

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 22nd, 2013 (1:28 pm)

    Sam Jaffe:
    RaymondJRam,

    Loboc,
    The biggest mistake that Boeing made is they chose laptop cell chemistry to put in their plane.

    This seems to be the first conclusion that everyone is jumping on……and that tells me that this is not the cause of the fires.

    It will be VERY interesting to see if the FAA directs Boeing to change the chemistry.


  30. 30
    nasaman

    +3

     

    Vote -1 Vote +1

    nasaman
     Says

     

    Jan 22nd, 2013 (2:12 pm)

    joe: Maybe it’s time for Boeing to call the GM Volt team for advice. Even “nasaman” could give them advice. It would not hurt anything, but their pride.

    volt11:
    It’s distressing to think that better engineering went into a car, namely the Volt, than a supposedly state-of-the-art commercial airplane.

    I’m flattered by your suggestion, Joe, and I agree with your comment, ‘Volt11′. For those here
    other than Noel (who likely knows what I’m about to say), GM acquired the Hughes Space and Communications operations in the late 1980′s —at the time they were the world’s largest maker of communications satellites & other spacecraft employing NiH2 batteries. It’s very likely GM still has engineers who are highly-experienced in extremely-reliable, long-life (20 yr) battery technology
    (and I’m reasonably sure those space battery experts had vitally-important inputs to the Volt battery design). This is one reason I’ve said here, more than once, that I’ll be both surprised as well as very disappointed if the Volt’s batteries don’t last at least 15 years without any failures or even significant capacity losses.

    Now, regarding the 787 batteries… I unfortunately retired before NASA began seriously considering (as they now are) replacing the ISS’ NiH2 batteries with Li-Ion batteries. However, we can all be assured that, if Li-Ion batteries wind up on the ISS, it won’t be because they weigh less (the ISS is weightless in orbit, right?) NASA will ONLY replace the proven NiH2 technology by some type of Li-Ion chemistry if they can be assured of higher reliability & longer life (i.e., >20yrs with NO failures)! So if Boeing is prudent, they’ll ask the National AERONAUTICS & Space Administration to make available battery experts for assistance/oversight as a part of their battery “red team” effort.


  31. 31
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 22nd, 2013 (2:26 pm)

    volt11:
    It’s distressing to think that better engineering went into a car, namely the Volt, than a supposedly state-of-the-art commercial airplane.

    Don’t forget. We have had fires in both the Volt AND the Karma….both of which have low combustion rates compared w/ CoO2.

    I’m skepticle this is a battery chemistry issue.


  32. 32
    nasaman

     

    Vote -1 Vote +1

    nasaman
     Says

     

    Jan 22nd, 2013 (3:04 pm)

    PS to my comments in #30 above: Boeing more recently acquired Hughes Space & Communications from GM, and they very likely already have some highly experienced, long-life, high-rel spacecraft battery specialists who could join their 787 red team effort.


  33. 33
    Bonaire

     

    Vote -1 Vote +1

    Bonaire
     Says

     

    Jan 22nd, 2013 (3:15 pm)

    George S. Bower: Don’t forget. We have had fires in both the Volt AND the Karma….both of which have low combustion rates compared w/ CoO2.I’m skepticle this is a battery chemistry issue.

    That’s true. Recapping: The Volt fires were not because of chemistry, they were (as said by GM) caused by crystalized coolant that perhaps dried and caused an internal short circuit in the punctured cell(s). The Fisker fires (parking lot and house) were due to overheated cooling fans in the front-engine area which spread through the engine compartment. The Newark, NJ parking lot flooded-by-Sandy fires – who knows but perhaps that salt water + battery systems were involved in short circuiting. So I don’t believe we have ever seen a car fire in an OEM EV caused by the actual battery cell chemistry. There may have been some EV fires by DIY home-conversions and EV drag racers, who knows. Neil Young’s EV that was DIY apparently caused a fire. The first ever house fire with a Volt in the garage (in CT) had the guy’s other DIY home-conversion in there too and may have been the cause.

    I suspect the Boeing issue is chemistry related due to a failed or bad BMS system causing in-flight overcharging. Could be either a design issue or manufacturing one. Could take weeks to determine it and speculation will continue.


  34. 34
    Streetlight

     

    Vote -1 Vote +1

    Streetlight
     Says

     

    Jan 22nd, 2013 (3:22 pm)

    George: Here’s an opened view of the two Li-ion systems locations.

    http://www.mcclatchydc.com/2013/01/15/179964/boeing-dreamliner-battery-fire.html

    The battery issues actually exposed a number of potential design concerns. I excerpted the following from the above article:

    “In the FAA tests, which the agency performed at its site in Atlantic City a year after it certified the Dreamliner, the temperature of the battery fires reached as high as 2,000 degrees Fahrenheit. The plane’s polymer skin melts at 649 degrees, according to its manufacturer, Victrex Energy of West Conshohocken, Pa.” (Curtis Tate | McClatchy Newspapers January 15, 2013)

    In other words, even once all come to a release, there will always be that potential of a fire exceeding 650 degrees (I assume Tate means F and not C)

    Just don’t fly any over North Africa.


  35. 35
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 22nd, 2013 (3:56 pm)

    Bonaire:

    I suspect the Boeing issue is chemistry related due to a failed or bad BMS system causing in-flight overcharging

    At the end of the article above the NTSB says that overcharging has been ruled out.


  36. 36
    Jeff

     

    Vote -1 Vote +1

    Jeff
     Says

     

    Jan 22nd, 2013 (4:02 pm)

    This is probably a stupid question, but WTH is a “combustion rate”? “C/min”? Is “C” the same unit as when rating cell current/capacity (A/Ah)?

    My first guess was just what it sounds like: how fast a cell will burn. But then a figure like 360C/min seems to render that meaningless. (i.e., 0.17 seconds/C(?))

    Is it an intrinsic property of a battery based on the battery chemistry? Or a unique battery cell spec provided by the battery supplier derivid from tests? Or a unique battery pack spec?

    And a Google search for “‘combustion rate’ battery” returns this page and an article from GreenCarCongress also about the 787 that copies the same quote from Charles Whalen in one of its comments. So I don’t seem to see this term elsewhere.


  37. 37
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 22nd, 2013 (4:03 pm)

    Streetlight:
    George: Here’s an opened view of the two Li-ion systems locations.

    http://www.mcclatchydc.com/2013/01/15/179964/boeing-dreamliner-battery-fire.html

    The battery issues actually exposed a number of potential design concerns. I excerpted the following from the above article:

    “In the FAA tests, which the agency performed at its site in Atlantic City a year after it certified the Dreamliner, the temperature of the battery fires reached as high as 2,000 degrees Fahrenheit.

    That seems to jive with what Charles Whalen said in the above article about deg/minute combustion rate.


  38. 38
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 22nd, 2013 (4:05 pm)

    Jeff:
    This is probably a stupid question, but WTH is a “combustion rate”?“C/min”?

    My first guess was just what it sounds like: how fast a cell will burn.But then a figure like 360C/min seems to render that meaningless.(i.e., 0.17 seconds/C(?))

    Is it an intrinsic property of a battery based on the battery chemistry?Or a unique battery cell spec provided by the battery supplier derivid from tests?Or a unique battery pack spec?

    And a Google search for “‘combustion rate’ battery” returns this page and an article from GreenCarCongress also about the 787 that copies the same quote from Charles Whalen in one of its comments.So I don’t seem to see this term elsewhere.

    I would assume that they ignited a battery and measured the rate of temperature rise after ignition.


  39. 39
    George S. Bower

    +1

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 22nd, 2013 (4:59 pm)

    Anyone interested in the Solar Impulse airplane? It’s pretty cool. Just as 787 they are using Li po’s. Same energy density as Yuasa’s. Only they are carrying 800 pounds of batteries@96 kwh of juice.

    That’s a lot juice.
    http://www.solarimpulse.com/en/airplane/hb-sia/


  40. 40
    haroldC

     

    Vote -1 Vote +1

    haroldC
     Says

     

    Jan 22nd, 2013 (5:02 pm)

    Noel Park,

    that pic of the plane gave me an odd fleeting impression it had only one engine….just for a sec…lol..
    haroldC


  41. 41
    Noel Park

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Jan 22nd, 2013 (5:55 pm)

    George S. Bower: Anyone interested in the Solar Impulse airplane? It’s pretty cool.

    #39

    Fantastic! +1


  42. 42
    Noel Park

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Jan 22nd, 2013 (5:56 pm)

    haroldC:
    Noel Park,

    that pic of the plane gave me an odd fleeting impression it had only one engine….just for a sec…lol..
    haroldC

    #40

    It never crossed my mind, but i see what you mean. I was too taken with the apparently flapping wings to pay attention.


  43. 43
    George S. Bower

    +2

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 22nd, 2013 (6:47 pm)

    Noel Park: #40

    It never crossed my mind, but i see what you mean.I was too taken with the apparently flapping wings to pay attention.

    I’m not sure if “flapping ” is the technically correct term, but one must admit:

    GM and Boeing are on the cutting edge. Way past anyone in this biz.

    Go Boeing!
    Go GM!
    Go USA!

    We love you.


  44. 44
    Noel Park

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Jan 22nd, 2013 (8:27 pm)

    George S. Bower: I’m not sure if “flapping ” is the technically correct term,

    #43

    Yeah, maybe “artfully curved” might have been a better choice of words, LOL. +1

    Wasn’t it the B52 that had some sort of struts with small wheels at the wingtips to hold up the ends of the wings on the ground when they drooped down after the weight of the plane came off of them?

    BTW, the more articles like this I read, the more I remember 2-3 years ago when I, along with some others, was bitching non-stop about how GM ought to take a little more risk, stop screwing round with all of the seemingly endless testing, and push the Volt out in the street to some of us volunteer “beta tester” customers.

    In retrospect, aaaahh, maybe not so much.


  45. 45
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 22nd, 2013 (8:38 pm)

    Noel Park: #43

    Yeah, maybe “artfully curved” might have been a better choice of words, LOL.+1

    Wasn’t it the B52 that had some sort of struts with small wheels at the wingtips

    No way. The B52 was probably the best bomber the US ever built. Still in service today (well pretty much, almost)

    The B52 didn’t need no training wheels.

    (but I may soon)


  46. 46
    Tom

     

    Vote -1 Vote +1

    Tom
     Says

     

    Jan 22nd, 2013 (8:52 pm)

    Raymondjram,

    ThinkPad’s have been manufactured by Lenovo for over 8 years. They are no longer IBM products.


  47. 47
    Raymondjram

     

    Vote -1 Vote +1

    Raymondjram
     Says

     

    Jan 22nd, 2013 (9:40 pm)

    Tom:
    Raymondjram,

    ThinkPad’s have been manufactured by Lenovo for over 8 years. They are no longer IBM products.

    All of the ThinkPads I have serviced were made by IBM before it was sold to Lenovo. I have worked with IBM systems since 1972 (when they used transistor logic called RTL and their boards were plugged into wire wrapped panels called “gates”) and I know almost all of its history after that (and most of the history before) so I stand by my facts. I actually have three working ThinkPads (600E, X41 and S10-2) but only the S10-2 is made by Lenovo, and it is my wife’s machine. The quality is still there.

    Raymond


  48. 48
    guyflyguy

     

    Vote -1 Vote +1

    guyflyguy
     Says

     

    Jan 22nd, 2013 (9:44 pm)

    Noel Park,

    The B47 had “pogos”
    The U2 had detachable wheels on the outboard wings


  49. 49
    Raymondjram

     

    Vote -1 Vote +1

    Raymondjram
     Says

     

    Jan 22nd, 2013 (9:48 pm)

    George S. Bower: No way. The B52 was probably the best bomber the US ever built. Still in service today (well pretty much, almost)

    The B52 didn’t need no training wheels.

    (but I may soon)

    The Boeing B-47 was fitted with wheels on the wing tips, and so was the Lockheed U-2 spy plane. I am good with aviation, too, not just computers.

    Raymond


  50. 50
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 22nd, 2013 (10:11 pm)

    Raymondjram: The Boeing B-47 was fitted with wheels on the wing tips, and so was the Lockheed U-2 spy plane. I am good with aviation, too, not just computers.

    Raymond

    OK here’s a test.
    Did the B2 bomber after it was the B1 get rid of it’s variable inlet intakes on its main engines?

    …or did it go to solid wings instead of swing wings….
    or both?


  51. 51
    George Ching

     

    Vote -1 Vote +1

    George Ching
     Says

     

    Jan 22nd, 2013 (11:19 pm)

    George S. Bower,

    If you mean the B1B, not the B2, then it went to fixed geometry intakes.

    Also, the B52, or any B52 I’ve seen, has does have small outrigger wheels near the wingtips. They keep the wing from flexing into the runway on landing, but don’t touch the ground when the aircraft is stationary.

    Do I pass?


  52. 52
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Jan 23rd, 2013 (8:17 am)

    George Ching:
    George S. Bower,

    If you mean the B1B, not the B2, then it went to fixed geometry intakes.

    Do I pass?

    With flying colors….and my mistake…it was the B1B I was talking about (duhh)


  53. 53
    George Ching

     

    Vote -1 Vote +1

    George Ching
     Says

     

    Jan 23rd, 2013 (8:59 pm)

    George S. Bower: With flying colors….and my mistake…it was the B1B I was talking about (duhh)

    I knew you knew the difference, George. We could probably waste a lot of hours talking aircraft.

    Thanks for the original post. Very concise and informative.


  54. 54
    GogogoStopSTOP

     

    Vote -1 Vote +1

    GogogoStopSTOP
     Says

     

    Jan 24th, 2013 (8:48 pm)

    It appears that there are only two remaining causes of failure: 1. Improper electronic charging design. 2. Battery defects, that have not been accounted for, that will create an unanticipated hazard during charging. Point 1 is being explored by Boeing, et. al. For point 2, it’s another story, because we’re dealing with defects interacting with an new design.

    Here’s the data they should have already looked at: What is the failure mode & location of all battery manufacturing tests results? I.e., during all phases of processing, assembly, intermediate & final test of all the battery’s, what defects prevented the battery from being shipped to a customer?

    Likewise, after shipping any of these batteries to customers, or technologically similar batteries, what has the customers experience been with failures in there next higher level of assembly & test & field operation? Unfortunately, for Boeing, we know their results… but I digress.

    Finally, what are the battery’s development team’s current plans to improve their product & when do they intend to introduce those improvements & why? Why this issue: Every product developer knows the weak points in his design, manufacturing & test process & has explicit or implicit plans to improve what’s been going wrong with his product, in his customers environment.

    They had better be on their way to get this info or they are gonna be a while figuring this out.