Boeing Dreamliner Battery Fire
- Thread starter mrbill
- Start date
LSBW
100 W
Problems with 787 is just tip of the iceberg. Look at the F35. Behind schedule, over priced and so much more problems to resolve.
Great industrious America is no more.
Great industrious America is no more.
Having worked as a final test tech in the aircraft flight guidance and display systems area of Honeywell back in the late 80s/early 90s, I would say that "passing multiple checks" is no guarantee that the stuff actually even works at all.Joseph C. said:
As one example, we had a little relay box for something on the MD8x series, I forget what it was for, about the size of a soda can. There was a computer-run test that was normally used on it, but often the (mini-mainframe-type) test computer was being used for troulbeshooting other equipment (flight computers, etc), so a manual test had to be run on a banana-plug-jumper test fixture instead. That test fixture and test had been around unchanged since the start of the MD-8x project, long before I started there, and used often. But there was part of the test that said to plug 28VDC into a specific jack, do a couple of other tests, and then to ground that jack. There was no step to unplug the 28VDC first.
The instructions were quite explicit step-by-step, and no test step was ever to be performed that was not explicitly called out, for any reason. So since I didn't really understand why they would want someone to plug ground into a 28VDC-powered jack, I performed the test exactly as written. POOF.
Fortunatley it's just a fuse that blew, turning off the test fixture and DUT. But it proved to me that NO ONE had ever performed the test as-written (if at all!), and it made me wonder what other tests people weren't doing, either becuase they didnt' want to, or because they "knew" that whoever wrote the test "really meant them to do X instead". But maybe they *didnt'* want that test run a different way, and so some possible error condition or failure was never being tested for, because someone thougth they knew better than the designer.
On the short-out test fault, I brought it up to the supervisor, who had NEVER been told about it before, in all his years there (guess he also never ran the test manually), and then we brought it up to engineering, who had never been told about it, and so on. I'm guessing that this test was done the same wrong way for at least a decade before I got there, and maybe a LOT more if it was the same test and fixture for the old DC-9 that the MD80 was based on! It took a long time (months? more than a year, I think), but we got the manual test changed to include a step to remove 28V first before grounding the jack. In the meantime, all testing HAD to be done on the computerized fixture, delaying shipments, becuase the manual test was "no longer" possible to run.
That wasnt' the only flaw, just with that single component's test. Later on, a batch of bad units got thru to McDonnell-Douglas, and they went onto planes (apparently passing *thier* test too), and then were rejected by the airlines (Alaska and I forget the other) themselves and sent back to us at Honeywell, because the relays turned out to be miswired in such a way that under a rare specifc set of conditions one of the relays could latch up and be un-resettable witout cutting power to that set of avionics (not something you want to do in-flight, I guess). We got them back, and they passed both the manual adn the computer test, so we opened them up and compared to the schematics and foudn the problem easily. But the problem still happened, and it escaped the test becaause not *all* possible wiring defects had been accounted for in the tests.
Another "untested" defect: the MD8x FMA, two per cockpit, has a four-section colored glass filter over the alphanumeric incandescent multi-segment displays, first section green, second amber, third and fourth green. All are called out in the tests and spec sheets to be "the same color" for all the green panels on a single filter. No actual color spec was given, so they could be any shade of green and still pass, as long as they were the same one between all panels.
Anywya, one day I was assigned as the new final test tech for the FMA, so I pulled them from burn-in, and ran the computerized tests, had any failures fixed, re-burned in, and put them in the darkroom for the lighting tests. Tested for light leaks around filters, cracks in the edgelit stuff, etc. Also the color test....well, every unit failed. Some had emerald green on one panel, and highlighter green, really yellow, on the next, and lime green on the third. Some were closer in shade.
Went to go get replacement filters (which we burned in separately for airline sales), and found ALL of them were bad the same way. That's dozens of bad filters at several hundred dollars a piece.
There were some that were kinda close, but none were "the same color" on all three panels. I checked with parts room and found that airlines had been ordering dozens and dozens ofn teh things for years, never sending us any bad parts back, just buying new ones. I guess they didn't like the mismatched colors, either. (this was confirmed in the months-long investigation fo the problem that "started" that day).
Turned out that a long time back, this problem *had* actually happened before, righta t the beginning of the project with prototypes, and a "gentleman's agreement" had been made with the provider (Chomerics? I forget exactly) that they would batch-sort the little green gels they used in the filters, and only use ones form the same color batch within the same filter. At some point a few years later, somebody new must've decided to simplify their manfuacturaing process, and leave out the sorting steps, sicne there was no actual color spec and "same color" could be interpreted in more than one way.
Why wasnt' this detected and stopped? Because before I took over, they had a red-green colorblind man doing the lighting tests on the finished units...and they knew he was, too!
Eventually the spec was changed to call out a very specific color on a color wheel, and a tolerance was given, and a colorimiter (or whatever they're called) added to the test room, so even a colorblind person could still run the tests. :lol:
As soon as we started shipping color-matched units, we never had another order for a spare filter. At all. Guess that says why they ordered so many--but it doesnt' explain why they wouldn't just tell us there's a problem, and have us fix it.
Neither of these problems was a critical one. Neither affected flight safety or anything, nor could have, AFAIK. But if these two things could go on for so long, until someone that cared enough came along to get them fixed, how many others could get thru, even just in onesies and twosies, if not wholesale?
I'll leave you with one more problem that *could* have been a real safety issue: An MD8x flight guidance computer was returned to us from Alaska airlines, becuase of an intermittent fault condition. Passed all our tests, so we opened it up, and in the bottom wirewrap section (yes, all these things used wirewrap for board interconnects, not PCBs!), a glyp (loctite) syringe needle was found stuck on a set of wirewrap pins. Guess it had been dropped in there when the Mexican wiring factory had been securing all the mounting hardware down, and being coated with loctite, it stuck on and stayed there. If the temperature was just right, it would short across a couple of pins, but not when it was warmer or colder than that, except under certain vibration conditions.
I guess whoever was doing visual inspections just didn't see it--there's a lot of wires down there, a real ratsnest, although slightly more orderly, so it was actually not that easy to spot. Took me probably 30 seconds of looking around at the wiring, maybe a minute, before I noticed it, and I already knew it was there because someone else had already found it and called us over to look.
And there was other stuff like that, too. Stuff we found inside units from Alaska Airlines that showed their techs were eating snacks and drinking soda and coffee right over the flight computers and other avionics, because they'd be returend to us for repair with bits of wrapper or spilled liquids in there. (which didn't hurt anything because it's all conformal-coated against liquids, but if they're taht careless about those things, what ELSE are they careless about?)
I've only flown once since I worked at Honeywell, and that's because I had no other way to get where I was going, and I was paranoid the whole trip from boarding to exit that something was going to go badly wrong at any moment, after all the stuff I'd seen just in one little section of one line at one company that provides stuff to the industry, and the similar stuff I heard about from others at other companies (or who had worked at other places before).
I know that the kind of problmes I saw aren't going to change, or go away--they're caused by insufficient caring about the job people are doing, and there's no way to keep people taht are really good and really care because the money is never good enough, and layoffs happen equally to those people adn the 9-5ers, only there to collect a paycheck and who don't give a crap if the work they do is right or not (they figure someone else will catch the problem and fix it for them, before it gets far enough to cause a crash). So I won't fly again unless there's no other way to get where I have to go...I'd rather just not go at all.
(edit: also, it's a little frustrating how many new threads on this I keep seeing get posted...been merging them all together into this one but it's work I'd rather not have to do, if poeple would just type a single word of their new thread's title into the search box.
)
bigmoose
1 MW
A new picture came out that shows a more pristine battery next to the krispy one. Also the article opined "overvoltage event."
Nice picture!
Then perhaps the seemingly oversophisticated BMS board sitting in the box didn't do it's job properly?
It looks like the box did a good job of containing the fire though. Probably just puked out a bunch of nasty smoke.
I wonder if the system is designed such that it can still operate after this kind of failure. Total electrical failure on an aircraft like this would be a complete disaster. I'm sure they have some kind of redundancy in the system. Of course there could still be some single failures that would take out the redundancy.
Years ago in the hospitial I work at there was a power failure. This is not uncommon, and the emergency generators fired up within 10 seconds. Unfourtunately the transfer switch that shifts the load to the generators blew and took out the emergency power to a large section of the building. Even when the grid came back up, the switch couldn't switch back. Luckily all areas have both 'regular' and 'emergency' power outlets and the critical loads were shifted to the regular circuits to keep things going.
Then perhaps the seemingly oversophisticated BMS board sitting in the box didn't do it's job properly?
It looks like the box did a good job of containing the fire though. Probably just puked out a bunch of nasty smoke.
I wonder if the system is designed such that it can still operate after this kind of failure. Total electrical failure on an aircraft like this would be a complete disaster. I'm sure they have some kind of redundancy in the system. Of course there could still be some single failures that would take out the redundancy.
Years ago in the hospitial I work at there was a power failure. This is not uncommon, and the emergency generators fired up within 10 seconds. Unfourtunately the transfer switch that shifts the load to the generators blew and took out the emergency power to a large section of the building. Even when the grid came back up, the switch couldn't switch back. Luckily all areas have both 'regular' and 'emergency' power outlets and the critical loads were shifted to the regular circuits to keep things going.
amberwolf said:Having worked as a final test tech in the aircraft flight guidance and display systems area of Honeywell back in the late 80s/early 90s, I would say that "passing multiple checks" is no guarantee that the stuff actually even works at all.
As one example, we had a little relay box for something on the MD8x series, I forget what it was for, about the size of a soda can. There was a computer-run test that was normally used on it, but often the (mini-mainframe-type) test computer was being used for troulbeshooting other equipment (flight computers, etc), so a manual test had to be run on a banana-plug-jumper test fixture instead. That test fixture and test had been around unchanged since the start of the MD-8x project, long before I started there, and used often. But there was part of the test that said to plug 28VDC into a specific jack, do a couple of other tests, and then to ground that jack. There was no step to unplug the 28VDC first.
The instructions were quite explicit step-by-step, and no test step was ever to be performed that was not explicitly called out, for any reason. So since I didn't really understand why they would want someone to plug ground into a 28VDC-powered jack, I performed the test exactly as written. POOF.
Fortunatley it's just a fuse that blew, turning off the test fixture and DUT. But it proved to me that NO ONE had ever performed the test as-written (if at all!), and it made me wonder what other tests people weren't doing, either becuase they didnt' want to, or because they "knew" that whoever wrote the test "really meant them to do X instead". But maybe they *didnt'* want that test run a different way, and so some possible error condition or failure was never being tested for, because someone thougth they knew better than the designer.
On the short-out test fault, I brought it up to the supervisor, who had NEVER been told about it before, in all his years there (guess he also never ran the test manually), and then we brought it up to engineering, who had never been told about it, and so on. I'm guessing that this test was done the same wrong way for at least a decade before I got there, and maybe a LOT more if it was the same test and fixture for the old DC-9 that the MD80 was based on! It took a long time (months? more than a year, I think), but we got the manual test changed to include a step to remove 28V first before grounding the jack. In the meantime, all testing HAD to be done on the computerized fixture, delaying shipments, becuase the manual test was "no longer" possible to run.
That wasnt' the only flaw, just with that single component's test. Later on, a batch of bad units got thru to McDonnell-Douglas, and they went onto planes (apparently passing *thier* test too), and then were rejected by the airlines (Alaska and I forget the other) themselves and sent back to us at Honeywell, because the relays turned out to be miswired in such a way that under a rare specifc set of conditions one of the relays could latch up and be un-resettable witout cutting power to that set of avionics (not something you want to do in-flight, I guess). We got them back, and they passed both the manual adn the computer test, so we opened them up and compared to the schematics and foudn the problem easily. But the problem still happened, and it escaped the test becaause not *all* possible wiring defects had been accounted for in the tests.
Another "untested" defect: the MD8x FMA, two per cockpit, has a four-section colored glass filter over the alphanumeric incandescent multi-segment displays, first section green, second amber, third and fourth green. All are called out in the tests and spec sheets to be "the same color" for all the green panels on a single filter. No actual color spec was given, so they could be any shade of green and still pass, as long as they were the same one between all panels.
Anywya, one day I was assigned as the new final test tech for the FMA, so I pulled them from burn-in, and ran the computerized tests, had any failures fixed, re-burned in, and put them in the darkroom for the lighting tests. Tested for light leaks around filters, cracks in the edgelit stuff, etc. Also the color test....well, every unit failed. Some had emerald green on one panel, and highlighter green, really yellow, on the next, and lime green on the third. Some were closer in shade.
Went to go get replacement filters (which we burned in separately for airline sales), and found ALL of them were bad the same way. That's dozens of bad filters at several hundred dollars a piece.
I checked with parts room and found that airlines had been ordering dozens and dozens ofn teh things for years, never sending us any bad parts back, just buying new ones. I guess they didn't like the mismatched colors, either. (this was confirmed in the months-long investigation fo the problem that "started" that day).
Turned out that a long time back, this problem *had* actually happened before, righta t the beginning of the project with prototypes, and a "gentleman's agreement" had been made with the provider (Chomerics? I forget exactly) that they would batch-sort the little green gels they used in the filters, and only use ones form the same color batch within the same filter. At some point a few years later, somebody new must've decided to simplify their manfuacturaing process, and leave out the sorting steps, sicne there was no actual color spec and "same color" could be interpreted in more than one way.
Why wasnt' this detected and stopped? Because before I took over, they had a red-green colorblind man doing the lighting tests on the finished units...and they knew he was, too!
Eventually the spec was changed to call out a very specific color on a color wheel, and a tolerance was given, and a colorimiter (or whatever they're called) added to the test room, so even a colorblind person could still run the tests. :lol:
As soon as we started shipping color-matched units, we never had another order for a spare filter. At all. Guess that says why they ordered so many--but it doesnt' explain why they wouldn't just tell us there's a problem, and have us fix it.
Neither of these problems was a critical one. Neither affected flight safety or anything, nor could have, AFAIK. But if these two things could go on for so long, until someone that cared enough came along to get them fixed, how many others could get thru, even just in onesies and twosies, if not wholesale?
I'll leave you with one more problem that *could* have been a real safety issue: An MD8x flight guidance computer was returned to us from Alaska airlines, becuase of an intermittent fault condition. Passed all our tests, so we opened it up, and in the bottom wirewrap section (yes, all these things used wirewrap for board interconnects, not PCBs!), a glyp (loctite) syringe needle was found stuck on a set of wirewrap pins. Guess it had been dropped in there when the Mexican wiring factory had been securing all the mounting hardware down, and being coated with loctite, it stuck on and stayed there. If the temperature was just right, it would short across a couple of pins, but not when it was warmer or colder than that, except under certain vibration conditions.
I guess whoever was doing visual inspections just didn't see it--there's a lot of wires down there, a real ratsnest, although slightly more orderly, so it was actually not that easy to spot. Took me probably 30 seconds of looking around at the wiring, maybe a minute, before I noticed it, and I already knew it was there because someone else had already found it and called us over to look.
And there was other stuff like that, too. Stuff we found inside units from Alaska Airlines that showed their techs were eating snacks and drinking soda and coffee right over the flight computers and other avionics, because they'd be returend to us for repair with bits of wrapper or spilled liquids in there. (which didn't hurt anything because it's all conformal-coated against liquids, but if they're taht careless about those things, what ELSE are they careless about?)
I've only flown once since I worked at Honeywell, and that's because I had no other way to get where I was going, and I was paranoid the whole trip from boarding to exit that something was going to go badly wrong at any moment, after all the stuff I'd seen just in one little section of one line at one company that provides stuff to the industry, and the similar stuff I heard about from others at other companies (or who had worked at other places before).
I know that the kind of problmes I saw aren't going to change, or go away--they're caused by insufficient caring about the job people are doing, and there's no way to keep people taht are really good and really care because the money is never good enough, and layoffs happen equally to those people adn the 9-5ers, only there to collect a paycheck and who don't give a crap if the work they do is right or not (they figure someone else will catch the problem and fix it for them, before it gets far enough to cause a crash). So I won't fly again unless there's no other way to get where I have to go...I'd rather just not go at all.
(edit: also, it's a little frustrating how many new threads on this I keep seeing get posted...been merging them all together into this one but it's work I'd rather not have to do, if poeple would just type a single word of their new thread's title into the search box.
You are statistically more likely to be hit by lightning than win the lotto. You are more likely to win the lotto than die in a plane accident. Planes are the safest form of transport. Planes are the safest form of transport...
Edit: Actually being serious - the thing that I would be most worried about is the competency of the pilot. When a plane crash does occur I'l bet that nine times out of ten it is the pilot's fault. Luckily I don't use regional airlines but statistically they would be the most likely to hire incompetent pilots.
Chalo
100 TW
Joseph C. said:fizzit said:Yeah cabin pressure was definitely not lost. But I don't think that the "Toulousains" can laugh after their problems with the A380
Would a wry smile be an acceptable substitute?
Not just acceptable, but so much more Continental.
LSBW
100 W
Amazing how guys in the kitchens, working for free, can make safer batteries than a bunch of overpaid engineers with U$32 billions budget.
Chalo
100 TW
LSBW said:
Don't kid yourself. Our lithium batteries have a high failure rate, in terms of mean cycles before failure. They are not ready for prime time. Those of us who use homemade lithium packs get by on perpetual vigilance, which is not an option for commercial products.
fizzit
10 kW
Joseph C. said:
Indeed.
Amberwolf, the kind of stuff you mentioned is definitely why outsourcing is one of the main causes for the Dreamliner's continuing problems. It's so much harder to keep tabs on the little details when things aren't being built in-house.
LSBW said:
I'm amazed at the sheer level of ignorance you have displayed in just one sentence.
liteCycles
10 W
Thanks Warren.
That is some bad karma.
That is some bad karma.
fizzit said:
Outsourcing for Boeing on commercial jetliners is nothing new. I worked as an engineer on the 777, from start to finish, and I can tell you that almost all of the equipment in the EE bay is produced by outside suppliers (this goes for all of their models that are currently in production). Only a small small fraction of electronics equipment was built "in-house" by Boeing Electronics, and they too were treated like any other outside supplier (Honeywell, Hamilton Standard, Sunstrand, Rockwell, etc.). Boeing does much of the structure fab in-house but for the most part they function as an integrator of complex systems. IMHO the problems that the 787 is experiencing have more to do with the significant leap in complexity and new technology, such as the composite structure and the fact that more and more of the systems that have in the past been powered with bleed air and engine driven pumps are now being driven electrically. So I would not say that outsourcing is the main culprit but it clearly makes the job of producing these jets more challenging and expensive.
Anyone have some news or detail about the battery fire in the Boeing 787 ?
answer to myself .... yes , news are here
http://endless-sphere.com/forums/viewtopic.php?f=14&t=46853&p=689686&hilit=boeing#p689686
Moderator Note: I moved this post where it belongs. Please Note that the Summary Thread is for summarizing events "that you personally have knowledge of..."
.
answer to myself .... yes , news are here
http://endless-sphere.com/forums/viewtopic.php?f=14&t=46853&p=689686&hilit=boeing#p689686
Moderator Note: I moved this post where it belongs. Please Note that the Summary Thread is for summarizing events "that you personally have knowledge of..."
.
mushymelon
1 kW
Federal investigations said Sunday that they had ruled out excessive voltage as the cause of a battery fire.
http://www.nytimes.com/2013/01/21/business/global/ntsb-rules-out-a-cause-for-battery-fire-on-787-dreamliner.html?partner=rss&emc=rss
http://www.nytimes.com/2013/01/21/business/global/ntsb-rules-out-a-cause-for-battery-fire-on-787-dreamliner.html?partner=rss&emc=rss
dnmun
1 PW
this article says they never exceeded 32V but there is no info on what the individual cells were charging up to. hard to believe these guys have the same newbie idea that total pack voltage is what matters. but there is a BMS so why could it not stop the current flow when it reached HVC?
Safety Board Rules Out a Cause for 787 Battery Fire
By JAD MOUAWAD
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.” The fire aboard a Japan Airlines plane on Jan. 7 at Logan International Airport in Boston occurred after the passengers had gotten off.
Last week, a battery problem on another 787 forced an All Nippon Airways jetliner to make an emergency landing in Japan. That episode prompted aviation authorities around the world to ground the plane, also known as the Dreamliner. The Federal Aviation Administration said last week that it would not lift the ban until Boeing could show that the batteries were safe.
But with investigators on a global quest to find out what went wrong, the safety board’s statement suggested that there might not be a rapid resumption of 787 flights. The 787 first entered service in November 2011 after more than three and a half years of production delays. Eight airlines currently own 50 787s, including United Airlines.
On Friday, Japanese safety officials, who are in charge of investigating the second battery problem, suggested that overcharging a battery might have caused it to overheat. Pilots decided to make an emergency landing 20 minutes after takeoff after receiving several alarms about the battery and smelled smoke in the cockpit.
That investigation is conducted by Japan’s transportation safety board. American investigators are heplping with the inquiry.
The GS Yuasa Corporation of Japan, one of the world’s leading lithium-ion battery manufacturers, makes the batteries for the 787, and Thales, of France, makes the control systems for the battery. The battery is part of a complex electrical system that powers the 787. Like many other components and structures, Boeing outsourced much of the manufacturing to partners around the world.
The safety board typically conducts investigations through a process of elimination, and rules out possible causes along the way.
It said that the lithium-ion battery that powered the auxiliary power unit, a small jet engine used on the ground, had been examined in the safety board’s Materials Laboratory in Washington.
The battery was first X-rayed and put through a CT scan. Investigators then disassembled it into its eight individual cells for detailed examination and documentation. Three of the cells were selected for more detailed radiographic examination.
Investigators have also examined several other components that they removed from the airplane, including wire bundles and battery management circuit boards as well as the battery management unit, the controller for the auxiliary power unit, the battery charger and the power start unit.
On Tuesday, investigators will convene in Arizona to test and examine the battery charger and download nonvolatile memory from the auxiliary power unit controller. Several other components have been sent for download or examination to Boeing’s facility in Seattle and to the manufacturer in Japan.
Safety Board Rules Out a Cause for 787 Battery Fire
By JAD MOUAWAD
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.” The fire aboard a Japan Airlines plane on Jan. 7 at Logan International Airport in Boston occurred after the passengers had gotten off.
Last week, a battery problem on another 787 forced an All Nippon Airways jetliner to make an emergency landing in Japan. That episode prompted aviation authorities around the world to ground the plane, also known as the Dreamliner. The Federal Aviation Administration said last week that it would not lift the ban until Boeing could show that the batteries were safe.
But with investigators on a global quest to find out what went wrong, the safety board’s statement suggested that there might not be a rapid resumption of 787 flights. The 787 first entered service in November 2011 after more than three and a half years of production delays. Eight airlines currently own 50 787s, including United Airlines.
On Friday, Japanese safety officials, who are in charge of investigating the second battery problem, suggested that overcharging a battery might have caused it to overheat. Pilots decided to make an emergency landing 20 minutes after takeoff after receiving several alarms about the battery and smelled smoke in the cockpit.
That investigation is conducted by Japan’s transportation safety board. American investigators are heplping with the inquiry.
The GS Yuasa Corporation of Japan, one of the world’s leading lithium-ion battery manufacturers, makes the batteries for the 787, and Thales, of France, makes the control systems for the battery. The battery is part of a complex electrical system that powers the 787. Like many other components and structures, Boeing outsourced much of the manufacturing to partners around the world.
The safety board typically conducts investigations through a process of elimination, and rules out possible causes along the way.
It said that the lithium-ion battery that powered the auxiliary power unit, a small jet engine used on the ground, had been examined in the safety board’s Materials Laboratory in Washington.
The battery was first X-rayed and put through a CT scan. Investigators then disassembled it into its eight individual cells for detailed examination and documentation. Three of the cells were selected for more detailed radiographic examination.
Investigators have also examined several other components that they removed from the airplane, including wire bundles and battery management circuit boards as well as the battery management unit, the controller for the auxiliary power unit, the battery charger and the power start unit.
On Tuesday, investigators will convene in Arizona to test and examine the battery charger and download nonvolatile memory from the auxiliary power unit controller. Several other components have been sent for download or examination to Boeing’s facility in Seattle and to the manufacturer in Japan.
thanks warren! what a find! you cant make this shit up! Leon is a hero! waht a clusterfcuk
why would a phd (cheng) design a bms? worst idea ever. phds are great at working on targeted problems not holistic systems
also the schematic didnt match the assembly documents which could result in a dead short
grunt phd
why would a phd (cheng) design a bms? worst idea ever. phds are great at working on targeted problems not holistic systems
also the schematic didnt match the assembly documents which could result in a dead short
grunt phd
Hillhater
100 TW
Battery details
http://www.gsyuasa-lp.com/aviation-lithium-batteries
http://www.s399157097.onlinehome.us/SpecSheets/LVP10-65.pdf
http://www.gsyuasa-lp.com/aviation-lithium-batteries
http://www.s399157097.onlinehome.us/SpecSheets/LVP10-65.pdf
good find @hill i wonder who made the decision to go with this chemistry aka lithium cobalt oxide- especially when japan has many reputable vendors like sony who makes quality cells nimh safe cells- we don't even use this stuff on our ebikes - what would make it good on a plain.... sure they pack energy but the industry is well aware of the intrinsically dangerous properties and unsafe nature of these cells
dnmun
1 PW
the contractor for the battery is Thales.
Hillhater
100 TW
davec said:
I am sure its not THE reason...but i read that they needed a very fast charge capability ( dont know how fast or why ?) and that was a factor in the decision.
But I AM sure there are better choices available, even if it is not the actual cells that are found to be at fault.
A French BMS? There's your problem :wink:
Actually, quite a lot of us use this chemistry on our ebikes. "RC LiPo" is LiCo(O2).davec said:
Just about every person in developed nations also uses this chemistry in at least one device around their house, and many carry them on their person, in the form of celphones, bluetooth headsets/earbuds, PDAs, MP3 players, etc.
