Whicker, I'd like to add a little addendum to your statement:
You wrote goals as: Who knows what the design target was.
Probably something like:
Needs to be X by Y by Z and weigh less than N Pounds and provide W watts.
Failure to deliver by time T, this will terminate contract with penalty.
Add to that: "Delivery ahead of schedule will result in x% reward per y time period."
Boeing has been massively delayed with this project and I'd think that numerous very senior people's futures have been at risk.
Exactly LiFePo4 Is WAY better and is Close to the safety of NiMH but still per Cu inch and Pound packs a punch.
Peter
LiFEPo4 has been lauded as the best ever Lithium ion chemistry. A lot of this seems to be due to that fact that this chemistry exists in natural rock formations and so the rationale is that it is very environmental.
But when it does fail, it out-gasses Hydrofluoric acid due to fluorine used in the electrolyte.
~~~~~~
We have seemed to gotten off into a lot of different issues, but my original reason for mentioning this is that the popular chemistry for battery technology might make a big shift from Lithium ion to NiMH. I have already done so in my own way as I have had personal frustrations with Lithium ion cells just being too sensitive to manage without a sophisticated control system.
If you short them, you may have a new cell instantaneously become worthless. If you run them down below their minimum discharge voltage, they become worthless. If you use the wrong charger, they may become worthless.
I have a collection of lithium cells as are divided into two groups -- those that died almost immediately and those that have served well for a long time. Cost wise, the sudden deaths have pretty much put me off on trying to use them without being provided with a sophisticated charge and discharge system.
Just as a data point, the destroyed motorcycle battery picture I previously posted was an LiFePO4 chemistry unit. The story was that the regulator malfunctioned, the electrical system overvolted. The rider stopped, turned everything off, smelled the heated battery and removed it from the bike. The battery then proceeded to continue it's meltdown with no connection to anything. Reportedly it was intact, not smoking, just smelled bad and moderately warm (able to be disconnected and manually removed without too much trouble, rider probably had gloves) upon removal from motorcycle. That said, it was on an older totally analog motorcycle and the stator output on some of those can reach into the 60 volt range so that battery was possibly hit with way more of a voltage insult than it could be designed for.
I saw this morning that there is nothing wrong with the batteries, and they are concentrating on the electronics.
That's comforting, somewhat. I personally think the battery design, chemistry and expected use is just fine. They (the Li batts as a family) just do not seem to safely handle bad inputs from their ancillary systems. The apparent positive feedback self destruction propensity is a little unnerving but potentially acceptable in the case of redundant management systems, I guess. There are many, many anecdotes of very obscure bugs in software/firmware/silicon having a hand in life threatening events. Sometimes "perfect" is the enemy of "good enough".......
I saw this morning that there is nothing wrong with the batteries, and they are concentrating on the electronics.
That's exactly what I would expect (and as has been said in one or two earlier postings at least) - the problem with lithium batteries isn't the battery itself, it's when the regulation and protection circuits fail. Just as with the mobile phone and notebook incidents in the past.
The news here in Seattle said specifically it was a battery monitoring system that they are focusing on.
If you look at how flat the curves are for charge and discharge, I begin to wonder how any battery monitoring system would manage.... unless they put a thermal sensor on each and every cell.
They may blame the battery monitoring system, but when you put more than 4 Lithium cells in series the problems of monitoring and managing proper charge and discharge grow immensely. It seems that there is a much higher degree of safety in systems that limit themselves to two cells in series at most. Three or four may be okay, but you start getting into huge matrices of wire, monitoring, and control.
If one cell in the middle of a series indicates a thermal danger, can yo isolate it and continue to use the rest? The solution to that question is likely to be very financially rewarding... if it can be done economically.
If you look at how flat the curves are ..... The solution to that question is likely to be very financially rewarding... if it can be done economically.
This is just an engineering issue. These questions should have been asked and answered in the design phase. The answer tell whether any solution can be found that is economic and safe. IF none can be found, use different batteries.
Waiting until the aircraft is in service to do this work is NOT the way we all agree is the best way to do this. The cost of re-spending the money to go back to the design phase and and re-engineering product in the field is reason enough, but on top of this there is the safety issue.
It looks like somebody pushed the schedule ahead and went with "quick and good enough for now" instead of spending the time to do it properly (as observed previously). I imagine management might be scrambling to deflect blame. We might expect the person responsible to be rewarded, and the person blamed to be convenient. "Blame-Avoidance" is a very risky and stressful management strategy, but often can be the result of previous choices.
No matter how the blame is deflected, it still lies within the 787. This is the price of "meeting schedules" over "completing the work".
IMHO, very similar to the Challenger (U.S. Space Shuttle) disaster. Lots of engineers knew it was a time bomb, the bean counters and profiteers ignored them. At least this time there may not be loss of life.
This is just an engineering issue. These questions should have been asked and answered in the design phase. The answer tell whether any solution can be found that is economic and safe. IF none can be found, use different batteries.
Waiting until the aircraft is in service to do this work is NOT the way we all agree is the best way to do this. The cost of re-spending the money to go back to the design phase and and re-engineering product in the field is reason enough, but on top of this there is the safety issue.
It looks like somebody pushed the schedule ahead and went with "quick and good enough for now" instead of spending the time to do it properly (as observed previously). I imagine management might be scrambling to deflect blame. We might expect the person responsible to be rewarded, and the person blamed to be convenient. "Blame-Avoidance" is a very risky and stressful management strategy, but often can be the result of previous choices.
No matter how the blame is deflected, it still lies within the 787. This is the price of "meeting schedules" over "completing the work".
"So this is just an engineering issue..." presumes that engineers know everything and given enough time they will get it right.
I beg to disagree as it is not engineering versus management so much as it is a 'product development' issue. And product development is always a rather hazardous process with open-ended R&D cost.
Let's start at the beginning with the De-Havaland Comet and please explain how it was just an engineering issue created by pushing a schedule. Enterfprises cannot wait around for the engineers to think of everything. There has to be some leadership with vision creating goals and setting limits.
D-day wasn't perfect either, but we won the war.
I take the view that we are in a constant process of discovery when we develop new products. And that being the case, we never get it everything quite right.
"So this is just an engineering issue..." presumes that engineers know everything and given enough time they will get it right.
You are hitting close to the issue. No, this does not presume engineers know every or are given unlimited time. It presumes that engineers engineer for the application. This involves determining if the solution fits the design parameters, and the design parameters fit the issue at hand. Defining the issue at hand, and defining the design parameters is the crux. One critical goal is to detemine whether the chosen strategy is really bad idea or not.
I beg to disagree as it is not engineering versus management so much as it is a 'product development' issue. And product development is always a rather hazardous process with open-ended R&D cost.
Designing a product when the R&D is not complete is very high risk. Space exploration and military campaigns involve such risks. Commercial travel cannot. Commercial products that are marketed and sold before the R&D is complete are prone to massive churn, as the end product needs to be re-worked as knowledge is discovered by R&D.
Let's start at the beginning with the De-Havaland Comet and please explain how it was just an engineering issue created by pushing a schedule.
Never said it was. This was an item that tried to bring very high tech to the masses, before they knew of the issues. And the issues came up, and people died. This is why we now say "Let's check for these type is things, since they went wrong before".
Enterfprises cannot wait around for the engineers to think of everything. There has to be some leadership with vision creating goals and setting limits.
Exactly. "Leadership" does not mean "get it out the door and start collecting money now regardless of the risks to our customers". It means "get it right to the best of our abilities, as dead customers offer little repeat business".
I take the view that we are in a constant process of discovery when we develop new products. And that being the case, we never get it everything quite right.
True. Please be cautious when participating in this particular set of discoveries, I would miss you.
Now they are going over the batteries internals with a microscope at a Naval facility back east.
Myself I do not think this is the Engineers fault at all. If they had known there was an issue I am pretty sure it would have come up at some point. Engineers are quite capable of figuring things out on the fly when need be. Consider Apollo 13. I have a feeling the end result is going to put blame on the manufacturer. They strayed away from the battery being at fault but are now back investigating the battery.
They have lots of engineers involved, but I wonder if they really have the right discipline. I suspect the endgame is going to be all about chemistry and the thermodynamics of the packaging.
Lithium cells have been recognized as stable in part because the size of the cell has been so small. As you scale up, you have less and less surface area to dump heat. And any good chemist knows that heat is a big factor in control of any chemical reaction.
Possible solution? Big Lithium battery cells may have to have cooling coils inserted and two opposing surfaces left open for tubing for coolant. In that way, heat from charge and discharge would be stablized quickly and not build to hazardous levels.
Small batteries don't need such as the amount of heat exchange in relation to the physical surface area that cools the cells is adequate for ambient cooling.
Possible solution? Big Lithium battery cells may have to have cooling coils inserted and two opposing surfaces left open for tubing for coolant. In that way, heat from charge and discharge would be stablized quickly and not build to hazardous levels.
The many Li Based EVs use coolant In the Packs ......The TESLA If I am awake enough to remember, is one of them, .
* I have a Trig test in 24 H . Brain is stuck in some where between a asymptote and cotangent .
According to the news stations here in Seattle they are back at focusing on the batteries. Apparently JAL had replaced close to 100 of them since taking delivery of the first 787.
Up-sized batteries, thermal runaway, nothing provided for cooling, nothing said about thermal monitoring or mitigation. They don't look like they provide for cooling in their photos......
If they want to stay with Lithium, or the same Lithium, they need to at least monitor what the thermal profile is in actual operation.
The good news is that while flying, the outside temperatures can easily cool the cells, but waiting on the tarmac may be what is really damaging the cells.
The number of cells is decided by the desired output voltage, not the total energy capacity.
If they want smaller cells they'd either have to connect them in parallell somehow(REALLY asking for trouble) or increase the output voltage.
It also means a much more advanced charger/monitor, possibly a DC-DC converter stage on he output(there may be one already, and they just need to adapt it for a higher input voltage)
One way to remove heat without massively redesigning everything could be to stick plates of aluminium between the cells and connect those to some sort of active cooling?
But what about the cold?
What's the ambient temperature in that compartment when the plane is cruising at high altitude, or parked at an airport overnight?
And what happens with these kinds of cells if exposed to extreme cold?
I suspect they really need to get back to flying ASAP. And I suspect that to do so, they at least need to have a comprehensive solution to monitor and mitigate the thermal situation in the battery storage areas.
They may not have enough of the right in-flight data unless the original scheme included the ambient temperature of the battery storage areas AND monitored the individual cells for heat build-up.
It really doesn't matter if they used Lithium or NiMH, both require a more restricted thermal environment to operated well than the good old lead acid. Neither likes freezing temperatures and about 40 degrees C is approaching sudden failure.
They can't afford to sit around with 50 grounded airplanes and design test schemes. And from what I understand, the modern jetliner is constantly feeding data to a homebase for collection and review.
Thank you for that link. It points to http://www.gsyuasa-lp.com/aviation-lithium-batteries which has a datasheet which confirms they are Lithium Cobalt's! That's so dumb, the engineers should have known better at both companies.
Well, Howard Hughes had an airline that served peanut butter sandwiches and Jet Blue started charging extra for pillows, right?
This would be the modern logical way to solve the problem. Just give it to someone else.
In truth, I am quite proud that the NTSB is making sure the US is not selling airliners that might in any way be hazardous. But I am very interested if lithium really is as good as all the hype we had been given.
I am still leaning towards NiMH for my own project in spite of the 18650 lithium cells as I have already suffered sudden losses due to letting children play with a robot. They just ran the cells too low to recover. It only takes once. And then any recharge attempt is a thermal hazard as the cell is shorted.
I am told that the picture of the burnt battery is a result of a nearby power panel by burning for 20 minutes before it was noticed. The batteries only caught fire because they were caught in a fire.
The batteries only caught fire because they were caught in a fire.
I'm not buying that one. Sounds like someone trying to CTA. JAL replaced close to 100 batteries since taking delivery of the 787. The news all over Seattle is showing they are back concentrating on the battery again. IMO, If there is even a remote chance of a fire they need to have some type of extinguishing system in place. The DC 10 was grounded in 1979 and we all know what happened to Mickey D's!!!! With foreign competition on the rise, BAC better get it together. They can not rely on their brad and butter 737's forever.
This could be in part due to a Japanese corporate culture not willing to embarrass the higher ups in the company with bad news. Something similar to what has gone on the nuclear industry and less to the tsunami caused tragedy.
The spec sheet for the actual battery is no longer available on their web site.
In something as major that this, it takes time for people to work through finding the problem. In the meantime, there are some that just generate spin and rumors do fly.
I have had overcharging of lead acid gel cells cause them to melt and distort. So the hazard is there for any rechargable battery in various degrees of severity. I find it hard to believe that a switch gear might have caught free and the fire migrated to the batteries. Switch gear is general designed to contain any electrical fire due to a connection or component failure.
Comments
Exactly LiFePo4 Is WAY better and is Close to the safety of NiMH but still per Cu inch and Pound packs a punch.
Peter
You wrote goals as: Who knows what the design target was.
Probably something like:
Needs to be X by Y by Z and weigh less than N Pounds and provide W watts.
Failure to deliver by time T, this will terminate contract with penalty.
Add to that: "Delivery ahead of schedule will result in x% reward per y time period."
Boeing has been massively delayed with this project and I'd think that numerous very senior people's futures have been at risk.
"Follow the money"
LiFEPo4 has been lauded as the best ever Lithium ion chemistry. A lot of this seems to be due to that fact that this chemistry exists in natural rock formations and so the rationale is that it is very environmental.
But when it does fail, it out-gasses Hydrofluoric acid due to fluorine used in the electrolyte.
~~~~~~
We have seemed to gotten off into a lot of different issues, but my original reason for mentioning this is that the popular chemistry for battery technology might make a big shift from Lithium ion to NiMH. I have already done so in my own way as I have had personal frustrations with Lithium ion cells just being too sensitive to manage without a sophisticated control system.
If you short them, you may have a new cell instantaneously become worthless. If you run them down below their minimum discharge voltage, they become worthless. If you use the wrong charger, they may become worthless.
I have a collection of lithium cells as are divided into two groups -- those that died almost immediately and those that have served well for a long time. Cost wise, the sudden deaths have pretty much put me off on trying to use them without being provided with a sophisticated charge and discharge system.
-Mike
If you look at how flat the curves are for charge and discharge, I begin to wonder how any battery monitoring system would manage.... unless they put a thermal sensor on each and every cell.
They may blame the battery monitoring system, but when you put more than 4 Lithium cells in series the problems of monitoring and managing proper charge and discharge grow immensely. It seems that there is a much higher degree of safety in systems that limit themselves to two cells in series at most. Three or four may be okay, but you start getting into huge matrices of wire, monitoring, and control.
If one cell in the middle of a series indicates a thermal danger, can yo isolate it and continue to use the rest? The solution to that question is likely to be very financially rewarding... if it can be done economically.
This is just an engineering issue. These questions should have been asked and answered in the design phase. The answer tell whether any solution can be found that is economic and safe. IF none can be found, use different batteries.
Waiting until the aircraft is in service to do this work is NOT the way we all agree is the best way to do this. The cost of re-spending the money to go back to the design phase and and re-engineering product in the field is reason enough, but on top of this there is the safety issue.
It looks like somebody pushed the schedule ahead and went with "quick and good enough for now" instead of spending the time to do it properly (as observed previously). I imagine management might be scrambling to deflect blame. We might expect the person responsible to be rewarded, and the person blamed to be convenient. "Blame-Avoidance" is a very risky and stressful management strategy, but often can be the result of previous choices.
No matter how the blame is deflected, it still lies within the 787. This is the price of "meeting schedules" over "completing the work".
"So this is just an engineering issue..." presumes that engineers know everything and given enough time they will get it right.
I beg to disagree as it is not engineering versus management so much as it is a 'product development' issue. And product development is always a rather hazardous process with open-ended R&D cost.
Let's start at the beginning with the De-Havaland Comet and please explain how it was just an engineering issue created by pushing a schedule. Enterfprises cannot wait around for the engineers to think of everything. There has to be some leadership with vision creating goals and setting limits.
D-day wasn't perfect either, but we won the war.
I take the view that we are in a constant process of discovery when we develop new products. And that being the case, we never get it everything quite right.
http://en.wikipedia.org/wiki/De_Havilland_Comet
You are hitting close to the issue. No, this does not presume engineers know every or are given unlimited time. It presumes that engineers engineer for the application. This involves determining if the solution fits the design parameters, and the design parameters fit the issue at hand. Defining the issue at hand, and defining the design parameters is the crux. One critical goal is to detemine whether the chosen strategy is really bad idea or not.
Designing a product when the R&D is not complete is very high risk. Space exploration and military campaigns involve such risks. Commercial travel cannot. Commercial products that are marketed and sold before the R&D is complete are prone to massive churn, as the end product needs to be re-worked as knowledge is discovered by R&D.
Never said it was. This was an item that tried to bring very high tech to the masses, before they knew of the issues. And the issues came up, and people died. This is why we now say "Let's check for these type is things, since they went wrong before".
Exactly. "Leadership" does not mean "get it out the door and start collecting money now regardless of the risks to our customers". It means "get it right to the best of our abilities, as dead customers offer little repeat business".
True. Please be cautious when participating in this particular set of discoveries, I would miss you.
Myself I do not think this is the Engineers fault at all. If they had known there was an issue I am pretty sure it would have come up at some point. Engineers are quite capable of figuring things out on the fly when need be. Consider Apollo 13. I have a feeling the end result is going to put blame on the manufacturer. They strayed away from the battery being at fault but are now back investigating the battery.
Lithium cells have been recognized as stable in part because the size of the cell has been so small. As you scale up, you have less and less surface area to dump heat. And any good chemist knows that heat is a big factor in control of any chemical reaction.
Possible solution? Big Lithium battery cells may have to have cooling coils inserted and two opposing surfaces left open for tubing for coolant. In that way, heat from charge and discharge would be stablized quickly and not build to hazardous levels.
Small batteries don't need such as the amount of heat exchange in relation to the physical surface area that cools the cells is adequate for ambient cooling.
The many Li Based EVs use coolant In the Packs ......The TESLA If I am awake enough to remember, is one of them, .
* I have a Trig test in 24 H . Brain is stuck in some where between a asymptote and cotangent .
Those are some big cells.
Wired: Boeings Batteries Draw Criticism as Dreamliner Probe Continues
and some additional info here:
http://www.wired.com/autopia/2013/01/boeing-787-investigation-batteries/
If they want to stay with Lithium, or the same Lithium, they need to at least monitor what the thermal profile is in actual operation.
The good news is that while flying, the outside temperatures can easily cool the cells, but waiting on the tarmac may be what is really damaging the cells.
If they want smaller cells they'd either have to connect them in parallell somehow(REALLY asking for trouble) or increase the output voltage.
It also means a much more advanced charger/monitor, possibly a DC-DC converter stage on he output(there may be one already, and they just need to adapt it for a higher input voltage)
One way to remove heat without massively redesigning everything could be to stick plates of aluminium between the cells and connect those to some sort of active cooling?
But what about the cold?
What's the ambient temperature in that compartment when the plane is cruising at high altitude, or parked at an airport overnight?
And what happens with these kinds of cells if exposed to extreme cold?
They may not have enough of the right in-flight data unless the original scheme included the ambient temperature of the battery storage areas AND monitored the individual cells for heat build-up.
It really doesn't matter if they used Lithium or NiMH, both require a more restricted thermal environment to operated well than the good old lead acid. Neither likes freezing temperatures and about 40 degrees C is approaching sudden failure.
They can't afford to sit around with 50 grounded airplanes and design test schemes. And from what I understand, the modern jetliner is constantly feeding data to a homebase for collection and review.
C.W.
The fact that they are Lithium Cobalt is very interesting. LiPO4 is suppose to be the most stable.
I'd like to see this on the TV commercials:
"The Boeing 787. Batteries not included".
Might change our perspective.
This would be the modern logical way to solve the problem. Just give it to someone else.
In truth, I am quite proud that the NTSB is making sure the US is not selling airliners that might in any way be hazardous. But I am very interested if lithium really is as good as all the hype we had been given.
I am still leaning towards NiMH for my own project in spite of the 18650 lithium cells as I have already suffered sudden losses due to letting children play with a robot. They just ran the cells too low to recover. It only takes once. And then any recharge attempt is a thermal hazard as the cell is shorted.
The spec sheet for the actual battery is no longer available on their web site.
In something as major that this, it takes time for people to work through finding the problem. In the meantime, there are some that just generate spin and rumors do fly.
I have had overcharging of lead acid gel cells cause them to melt and distort. So the hazard is there for any rechargable battery in various degrees of severity. I find it hard to believe that a switch gear might have caught free and the fire migrated to the batteries. Switch gear is general designed to contain any electrical fire due to a connection or component failure.
Read Dr. Henry Petroski's book,"To Engineer is Human"; pages 176-180.
Also read pages 181-184; and watch the movie "No Highway" staring Jimmy Stewart.
cheers, David