melodious
100 kW
Maybe they didn't choose LiFePO4 because it has a performance penalty in colder environments, which would be the case outside of the cabin area?ebent said:
Boeing Dreamliner Battery Fire
- Thread starter mrbill
- Start date
ebent
10 kW
Wide Working Temperature Range - From -4 F to 150 F (-20C to +70C) Extremely cold and extremely hot weather will not effect its performance. This comes from the Ping website. The availability of LiFePO4 is not an issue!
Hillhater
100 TW
Punx0r said:
Weight was a primary factor in the decision for Boeing.
Power and energy density, price , reliability, etc were also factors no doubt.
Switching to another chemistry will probably compromise some of those advantages,..
... but i am sure they would never compromise safety in order to gain a little weight or energy density advantage
Or , to put it another way, i am sure they would happily compromise weight , energy, size , etc, in order to improve safety and get flying again.
ebent
10 kW
My best guess. They can't condescend and admit that LiFePO4 is safer. Because by doing so it is the same as admitting they poorly specified the problem battery. They must find a way to make the cobalt safe. Anything else is career ending. Even if changing chemistry is best. When comparing battery attributes the cobalt usually looks best. From a scientific point of view. And unfortunately overlooking safety. And the differences are very modest. Discharge rate is the difference. But most applications LiFePO4 gets it done.
Hillhater
100 TW
Not necessarily they only used 5C LiCo cells. ....is 120C LiFePo4 good enough ?ebent said:
http://www.gebattery.com.cn/geb/EN/ProductList.asp?SortID=167&SortPath=0,133,167,
999zip999
100 TW
Hype 120C. Price ?
Hillhater
100 TW
I doubt the price is a consideration for Boeing at this point ( or any other )
..but $30 per cell has been quoted.
Note: .. I am not suggesting this cell is a solution to the Boeing issue, rather simply saying that discharge capacity of LiFePo4 is not a limiting factor.
..but $30 per cell has been quoted.
Note: .. I am not suggesting this cell is a solution to the Boeing issue, rather simply saying that discharge capacity of LiFePo4 is not a limiting factor.
ebent
10 kW
PunxOr,
You indicated that you are "not completly up on LiFePO4, so I could be wrong here". So before you claim my comments are not true, may I suggest you research the subject before you claim that my comment is not true! That would be reasonable. Here is a link from Ping. http://www.pingbattery.com/servlet/StoreFront they indicate the temp range at Ping. There is antidotal commentary that is different. Regardless, IF temps were an issue a heater or heat tape could resolve the problem for the dreamliner IF it was an issue. It seems you do not want LiFePO4 to work. Is there motivation for that?
You indicated that you are "not completly up on LiFePO4, so I could be wrong here". So before you claim my comments are not true, may I suggest you research the subject before you claim that my comment is not true! That would be reasonable. Here is a link from Ping. http://www.pingbattery.com/servlet/StoreFront they indicate the temp range at Ping. There is antidotal commentary that is different. Regardless, IF temps were an issue a heater or heat tape could resolve the problem for the dreamliner IF it was an issue. It seems you do not want LiFePO4 to work. Is there motivation for that?
Yes, I own a huge number of shares in manufacturers making Lico cells and as usual it's all a conspiracy 
I'm not in favour of lico, just questioning the assumption that lifepo4 is/was the obvious choice for these batteries. It's not as far as I know, mainly due to availability, hence asking if anyone else knows differently.
My "not true" comment was aimed at the pingbattery website, not yourself. We all know it's not true (basic knowledge of chemical reactions and empirical evidence from people riding ebikes in cold weather). Pingbattery may make fine batteries for amateur EV's, but they are completely unsuitable as a source for a serious commercial project, let alone an airliner.
I'm not in favour of lico, just questioning the assumption that lifepo4 is/was the obvious choice for these batteries. It's not as far as I know, mainly due to availability, hence asking if anyone else knows differently.
My "not true" comment was aimed at the pingbattery website, not yourself. We all know it's not true (basic knowledge of chemical reactions and empirical evidence from people riding ebikes in cold weather). Pingbattery may make fine batteries for amateur EV's, but they are completely unsuitable as a source for a serious commercial project, let alone an airliner.
My take would be that LiFePO4 has about half the volumetric energy density of LiCo. The batteries would need to be almost twice as large and significantly heavier, but still better than NiCd.
ebent
10 kW
Thanks fechter for that info. I assume you believe it would be a safer application. Part of Boeings solution is to create a box with lots of spacing for the LiCo batteries. So part of the additional volume will already be used up on the spacing. It appears that most of the penalty is weight not volume. I have no idea what the current battery weighs or how much more would be required for LiFePO4. For the sake of safety add the weight and reduce the risk. Any airplane application should have the ultimate on safety. Relative to all batteries.
dnmun
1 PW
but you are presupposing that the fire events were because it is lipo instead of lifepo4.
the problem could easily be in the wiring if the news of their discovery of the wiring errors is valid.
it could be a fault in the documentation of how to do a battery replacement that leaves some status hindered that was not in the original machine status worst case solutions and it is a supervisory function that has failed? these are all japanese fleet planes also.
the problem could easily be in the wiring if the news of their discovery of the wiring errors is valid.
it could be a fault in the documentation of how to do a battery replacement that leaves some status hindered that was not in the original machine status worst case solutions and it is a supervisory function that has failed? these are all japanese fleet planes also.
dogman dan
1 PW
Yep, shorted wiring can start a fire with any chemistry. I find it amusing though, that thier solution turns out to be what I keep preaching to guys who tape HK packs to thier bike frames.
Put em in a good box, I keep saying. On a plane in flight, I'd want em in an outstanding good box.
Put em in a good box, I keep saying. On a plane in flight, I'd want em in an outstanding good box.
ebent
10 kW
Good point dnmun,
I know I could start a fire with a common aaa battery. Without doubt there are a ton of variables. That will always be true. The fact remains that the most volatile chemistry is LiCO. My contention is that in an airplane, or any other environment that fire can't be tolerated Don't use it. There are other choices that can provide the needed electricity with much lower risk. The extra weight penalty for LiFePO4 is a modest price to pay for the risk removed. Regardless of what started the fire, I feel that using LiCO on the dreamliner is a poor and libelous specification. LiCO has the worst history. Managing risk is to improve the probability of safety. Can't get rid of it. You sure can improve the probabilities.
Perhaps one day the safety issues will be resolved with LiCO. There are no other complaints. In the mean time don't put it on airplanes other than drones.
I know I could start a fire with a common aaa battery. Without doubt there are a ton of variables. That will always be true. The fact remains that the most volatile chemistry is LiCO. My contention is that in an airplane, or any other environment that fire can't be tolerated Don't use it. There are other choices that can provide the needed electricity with much lower risk. The extra weight penalty for LiFePO4 is a modest price to pay for the risk removed. Regardless of what started the fire, I feel that using LiCO on the dreamliner is a poor and libelous specification. LiCO has the worst history. Managing risk is to improve the probability of safety. Can't get rid of it. You sure can improve the probabilities.
Perhaps one day the safety issues will be resolved with LiCO. There are no other complaints. In the mean time don't put it on airplanes other than drones.
dnmun
1 PW
no, AAA will not start fires form overcharging. that is not what i meant. NiCad is most volatile imo. there is no way to monitor the individual cells and so many needed in parallel it is not a solution imo.
these packs have gone through extensive testing and this problem did not appear and it has only appeared in the packs of just two japanese national airlines on packs that had been removed and replaced into the airplane. so they had been subject to some form of maintenance by the airline mechanics. the documentation would be translated to japanese.
they may have a charging station at the airplane maintenance facility that is somehow damaging the packs when they are mounted on it and tested or recharged. all these packs appear to have been removed and then reinstalled later. it may be the installation can damage them or they are reinstalled fully charged and the supervisory functions can not tell that so it continues charging it after it is full.
when you jump to conclusions before knowing the facts and can make correlations to all events in the pack history then you are reducing the chances to find the cause.
but to get these planes in the air and be safe enuff to meet the FAA concerns now they are gonna be separated so thermal runaway in one does not provoke thermal runaway in the other cells and they now will have it in a vented cabinet so the gases can be expelled from the plane. they may even build into the cabinet the ability to inject the halon or whatever fire extinguishing atmosphere through individual ports right at the location of each cell to provide cooling.
these packs have gone through extensive testing and this problem did not appear and it has only appeared in the packs of just two japanese national airlines on packs that had been removed and replaced into the airplane. so they had been subject to some form of maintenance by the airline mechanics. the documentation would be translated to japanese.
they may have a charging station at the airplane maintenance facility that is somehow damaging the packs when they are mounted on it and tested or recharged. all these packs appear to have been removed and then reinstalled later. it may be the installation can damage them or they are reinstalled fully charged and the supervisory functions can not tell that so it continues charging it after it is full.
when you jump to conclusions before knowing the facts and can make correlations to all events in the pack history then you are reducing the chances to find the cause.
but to get these planes in the air and be safe enuff to meet the FAA concerns now they are gonna be separated so thermal runaway in one does not provoke thermal runaway in the other cells and they now will have it in a vented cabinet so the gases can be expelled from the plane. they may even build into the cabinet the ability to inject the halon or whatever fire extinguishing atmosphere through individual ports right at the location of each cell to provide cooling.
dnmun
1 PW
from the nytimes:
February 22, 2013
F.A.A. Sets Terms for Boeing’s Battery Fixes on the 787
By CHRISTOPHER DREW and JAD MOUAWAD
After meeting with Boeing executives, top federal aviation officials said on Friday that they would not approve any fix to the battery problems on the 787 jetliner until they were certain that the batteries would not fail again.
“The safety of the flying public is our top priority and we won’t allow the 787 to return to commercial service until we’re confident that any proposed solution has addressed the battery failure risks,” Laura J. Brown, a spokeswoman for the Federal Aviation Administration, said in a statement.
At the meeting on Friday, more than five weeks after the plane was grounded, Boeing executives outlined the company’s latest proposals on how to keep the 787’s new lithium-ion batteries from overheating and how to vent any smoke or hazardous gases out of the plane.
Raymond L. Conner, the president of Boeing’s commercial airplane division, led the group of executives that met with Michael P. Huerta, the administrator of the F.A.A., and John Porcari, the deputy transportation secretary.
The meeting, however, was unlikely to bring about a quick lifting of the 787s’ grounding order. Boeing is asking the F.A.A. to approve the fixes even though safety investigators have not figured out precisely what caused the battery on one plane to ignite and the battery on another to start smoking last month.
After the meeting, federal officials said Boeing would be allowed to conduct a series of test flights to see how the fixes work and to fine-tune its proposals.
Boeing officials say that even though the causes of the battery episodes have not been determined, they have identified the most likely ways in which the new lithium-ion batteries failed. They now want the F.A.A. to approve changes meant to virtually eliminate the odds of future cases and to protect the plane and its passengers if a problem does arise.
In that sense, the meeting on Friday was also aimed at expanding the company’s emphasis from engineering work to the political arena. Besides evaluating the merits of its proposals, Mr. Huerta and the transportation secretary, Ray LaHood, might have to make difficult decisions about how well the fixes minimize the safety risk. Mr. LaHood said last month that the planes “won’t fly until we’re one thousand percent sure they are safe to fly.”
But battery and aviation-safety experts say that it could be hard to meet that standard if the causes of the recent episodes are not totally clear. And the F.A.A. often has to walk a delicate line in balancing its role in promoting aviation as well as ensuring safety.
Engineers at the agency have worked closely with Boeing in developing the possible fixes, and their general support for the concept was crucial in enabling the company to bring those proposals to Mr. Huerta and Mr. Porcari.
But Peter Goelz, a former managing director of the National Transportation Safety Board, an independent board that is investigating the battery problems, said: “These kinds of things always raise the basic question: Is the F.A.A. really a participant or a regulator in this, and how does it play the role of regulator when the only way to get to a solution is by being a partner? It’s always a fine line.”
Mr. Goelz and other former safety officials said Boeing’s proposals were on the right track. But some battery experts said they would like to hear more details about how Boeing would keep the batteries from overheating before judging how well the plans would work.
Boeing has delivered 50 787s so far to eight airlines. The company has much riding on the innovative planes. They are the first commercial jets to be built mostly out of lightweight composite materials that reduce fuel costs. Boeing has orders for 800 more of these planes, nicknamed the Dreamliner.
Investigators at the safety board said a battery that ignited on a 787 parked at Logan Airport in Boston in January had suffered thermal runaway, a chemical reaction that leads the battery to overact. They said the problem started in one of the eight cells in the batteries and spread to the others.
On Friday, Boeing proposed adding insulation between the cells to minimize the risk of a short-circuit cascading through most or all of them.
The company also proposed to add systems to monitor the temperature and activity inside each cell. It would enclose the batteries in sturdier steel boxes to contain any fire, and it would create tubes to vent hazardous gases outside the plane.
Boeing said the redesigned batteries would fit in the same space. After the meeting, it also said in a statement that it was “encouraged by the progress being made toward resolving the issue and returning the 787 to flight for our customers and their passengers around the world.”
February 22, 2013
F.A.A. Sets Terms for Boeing’s Battery Fixes on the 787
By CHRISTOPHER DREW and JAD MOUAWAD
After meeting with Boeing executives, top federal aviation officials said on Friday that they would not approve any fix to the battery problems on the 787 jetliner until they were certain that the batteries would not fail again.
“The safety of the flying public is our top priority and we won’t allow the 787 to return to commercial service until we’re confident that any proposed solution has addressed the battery failure risks,” Laura J. Brown, a spokeswoman for the Federal Aviation Administration, said in a statement.
At the meeting on Friday, more than five weeks after the plane was grounded, Boeing executives outlined the company’s latest proposals on how to keep the 787’s new lithium-ion batteries from overheating and how to vent any smoke or hazardous gases out of the plane.
Raymond L. Conner, the president of Boeing’s commercial airplane division, led the group of executives that met with Michael P. Huerta, the administrator of the F.A.A., and John Porcari, the deputy transportation secretary.
The meeting, however, was unlikely to bring about a quick lifting of the 787s’ grounding order. Boeing is asking the F.A.A. to approve the fixes even though safety investigators have not figured out precisely what caused the battery on one plane to ignite and the battery on another to start smoking last month.
After the meeting, federal officials said Boeing would be allowed to conduct a series of test flights to see how the fixes work and to fine-tune its proposals.
Boeing officials say that even though the causes of the battery episodes have not been determined, they have identified the most likely ways in which the new lithium-ion batteries failed. They now want the F.A.A. to approve changes meant to virtually eliminate the odds of future cases and to protect the plane and its passengers if a problem does arise.
In that sense, the meeting on Friday was also aimed at expanding the company’s emphasis from engineering work to the political arena. Besides evaluating the merits of its proposals, Mr. Huerta and the transportation secretary, Ray LaHood, might have to make difficult decisions about how well the fixes minimize the safety risk. Mr. LaHood said last month that the planes “won’t fly until we’re one thousand percent sure they are safe to fly.”
But battery and aviation-safety experts say that it could be hard to meet that standard if the causes of the recent episodes are not totally clear. And the F.A.A. often has to walk a delicate line in balancing its role in promoting aviation as well as ensuring safety.
Engineers at the agency have worked closely with Boeing in developing the possible fixes, and their general support for the concept was crucial in enabling the company to bring those proposals to Mr. Huerta and Mr. Porcari.
But Peter Goelz, a former managing director of the National Transportation Safety Board, an independent board that is investigating the battery problems, said: “These kinds of things always raise the basic question: Is the F.A.A. really a participant or a regulator in this, and how does it play the role of regulator when the only way to get to a solution is by being a partner? It’s always a fine line.”
Mr. Goelz and other former safety officials said Boeing’s proposals were on the right track. But some battery experts said they would like to hear more details about how Boeing would keep the batteries from overheating before judging how well the plans would work.
Boeing has delivered 50 787s so far to eight airlines. The company has much riding on the innovative planes. They are the first commercial jets to be built mostly out of lightweight composite materials that reduce fuel costs. Boeing has orders for 800 more of these planes, nicknamed the Dreamliner.
Investigators at the safety board said a battery that ignited on a 787 parked at Logan Airport in Boston in January had suffered thermal runaway, a chemical reaction that leads the battery to overact. They said the problem started in one of the eight cells in the batteries and spread to the others.
On Friday, Boeing proposed adding insulation between the cells to minimize the risk of a short-circuit cascading through most or all of them.
The company also proposed to add systems to monitor the temperature and activity inside each cell. It would enclose the batteries in sturdier steel boxes to contain any fire, and it would create tubes to vent hazardous gases outside the plane.
Boeing said the redesigned batteries would fit in the same space. After the meeting, it also said in a statement that it was “encouraged by the progress being made toward resolving the issue and returning the 787 to flight for our customers and their passengers around the world.”
ebent
10 kW
On aaa batteries I meant that if I needed to start a fire and had no matches, I could rig up a short and cause a fire. Meaning that all energy sources could cause fire. I agree with all you say dnmun. I say regardless what caused the fire my opinion is keep the chemistry benign if it can get the work done.
Example. Take 2 sets of battery needs. And create 10000 sets of LIPO and 10000 of LiFePO4. Both made by qualified sources. Both applied to the same or similar task. Say the demands are like the needs of a dreamliner. My best guess in large numbers there will be a higher number of fires or explosions etc. with the LiCO. I think that history agrees with me.
So even if the fire was not caused by the LiCo, my point is if it is more likely a problem specify something else if it can get the work done. That specification would reduce the number of issues. Statistics. I have never been concerned if the battery caused the fire.
If I'm wrong I would appreciate the what is right. That single point is I feel LIPO is inherently more likely to cause a problem. Especially when there are multiple parties providing service and charging. But if that ain't it, please tell me.
Example. Take 2 sets of battery needs. And create 10000 sets of LIPO and 10000 of LiFePO4. Both made by qualified sources. Both applied to the same or similar task. Say the demands are like the needs of a dreamliner. My best guess in large numbers there will be a higher number of fires or explosions etc. with the LiCO. I think that history agrees with me.
So even if the fire was not caused by the LiCo, my point is if it is more likely a problem specify something else if it can get the work done. That specification would reduce the number of issues. Statistics. I have never been concerned if the battery caused the fire.
If I'm wrong I would appreciate the what is right. That single point is I feel LIPO is inherently more likely to cause a problem. Especially when there are multiple parties providing service and charging. But if that ain't it, please tell me.
I'd take high quality LICO over hobbyking lifepo4 any day HK products don't even have the main leads connected up the right way...
This is my point: It's all very well to criticise the lico cell choice, but IMO it's invalid to do so without offering a better alternative.
I'm working on the assumption that the lico cells chosen at the time were the best solution available. Even Tesla snubbed lifepo4 more recently in favour of lico. It's difficult to imagine this was also the result of crass stupidity.
Dnmun, AFAIK the nicd used in aircraft are large format cells, so quite possibly 1P parallel packs. I don't know if they had individual cell monitoring. I just know some people have salvaged such cells for EV purposes. They were also used in OEM EV's years ago until Shell(?) bought up the rights and restricted anything larger than a D-cell for EV use (hence the prius packs).
HK products don't even have the main leads connected up the right way...This is my point: It's all very well to criticise the lico cell choice, but IMO it's invalid to do so without offering a better alternative.
I'm working on the assumption that the lico cells chosen at the time were the best solution available. Even Tesla snubbed lifepo4 more recently in favour of lico. It's difficult to imagine this was also the result of crass stupidity.
Dnmun, AFAIK the nicd used in aircraft are large format cells, so quite possibly 1P parallel packs. I don't know if they had individual cell monitoring. I just know some people have salvaged such cells for EV purposes. They were also used in OEM EV's years ago until Shell(?) bought up the rights and restricted anything larger than a D-cell for EV use (hence the prius packs).
ebent
10 kW
To make a valid test, compare the best Lifepo4 to the best Lico. Comparing the best LiCo to the worst Lifepo4 is invalid.
drewjet
10 kW
Punx0r said:I'd take high quality LICO over hobbyking lifepo4 any day
Dnmun, AFAIK the nicd used in aircraft are large format cells, so quite possibly 1P parallel packs. I don't know if they had individual cell monitoring. I just know some people have salvaged such cells for EV purposes. They were also used in OEM EV's years ago until Shell(?) bought up the rights and restricted anything larger than a D-cell for EV use (hence the prius packs).
Aircraft Nicad are large format, and usually not parallel. There is no individual cell monitoring, and they are extremely reliable...and heavy(Very close in energy density to lead). They are serviceable to, you can refill the fluid in them and easily change out bad cells as they are bolted together, this is usually done in a shop.
Hillhater
100 TW
Define.. "Best"Punx0r said:What is the best lifepo4?
Lightest ?
Safest ?
Longest cycle life ?
Highest "C" rate ?
Lowest cost ?
Etc etc
dnmun
1 PW
flightiest?
Wall Street journal: Elon Musk from Tesla cars
http://blogs.wsj.com/corporate-inte...on-musks-solution-to-boeings-battery-problem/
http://blogs.wsj.com/corporate-inte...on-musks-solution-to-boeings-battery-problem/
