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#181
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Is the 787 a failure ?
On Fri, 22 Mar 2013 09:23:17 -0000, "Keith W"
wrote: The conventional Batteries are sometimes called Sealed Lead Acid Batteries but they are actually AGM batteries. Modern passenger aircraft normally use Nickel Cadmium batteries Why havent they converted over to NmH? |
#182
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Is the 787 a failure ?
Daryl wrote:
On 3/22/2013 3:23 AM, Keith W wrote: Daryl wrote: On 3/22/2013 12:55 AM, Mr. B1ack wrote: On Fri, 22 Mar 2013 03:00:07 +0000 (UTC), (Bradley K. Sherman) wrote: Who are you gonna believe, Boeing or your own lying eyes? Boeing Co. (BA)'s assertion that U.S. investigators ruled out a fire within the battery case of a Japan Airlines Co. (9201) 787 is premature, a National Transportation Safety Board spokesman said. Investigators examining the Jan. 7 fire aboard the Dreamliner in Boston haven't ruled out that flames erupted within the lithium-ion battery container, Peter Knudson said today in response to questions about the issue. ... Michael Sinnett, Boeing's chief project engineer, said in the briefing that investigators hadn't found evidence of flames within the Boston battery's container box, an indication it worked as designed to limit damage from a battery failure. A witness who tried to fight the Jan. 7 fire said he saw 3- inch (7.6-centimeter) flames outside the lithium-ion battery, and the NTSB has found evidence of high temperatures within battery cells that failed, according to preliminary safety-board documents released March 7. ... http://www.businessweek.com/news/2013-03-15/ntsb-contradicts-boeing-claim-of-no-fire-in-787-battery --bks Gawd ... is THIS thread still going on ???????????/ Yes, the 787 is a failure. Put it this way ... after hearing about its problems *I* will NEVER fly on one - ever. And I'm hardly the only one who feels this way. Not interested in burning to death over the Pacific .... The conventional Batteries are sometimes called Sealed Lead Acid Batteries but they are actually AGM batteries. Modern passenger aircraft normally use Nickel Cadmium batteries Which are prone to a lot of problems. And it's old tech. Now for the real negatives. If you overcharge them, they overheat. If you let them go down below 20% they will need to be taken out and charged very, very slowly with a special charger. They are very susceptible to temperature ranges. They are the heaviest of the Non Lead Acid batteries, their life span is almost equal to the sealed lead acid if you don't count the fact they damage easy. The cost is more than the AGM. The AGM is just now finding it's way into the aircraft industry. Of course, it has been somewhat over looked because of the Lithiums. But it appears that small aircraft that are worried about initial building costs are not overlooking them. What they are looking at is the replacement hours on the Lithiums. They start out at 800 charges and go to 2000 charges depending on the type of Lithium. The weights in comparison to the AGM is anywhere 3 times to 5 times lighter. But the cost is at least 5 times the cost. Less time between replacements, requires a heated and cooled area but is the most dependable. If that is all that is keeping the 787 from flying, it's a pretty simple fix. Not necessarily as that may need recertification which is a complex and lengthy since the batteries would be heavier and take up more space. They are going to have to be re certified anyway. The AGM isn't that much larger and it's pretty well proven in the Electric Vehicles to day. Most electrical vehicles do not use AGM's, their energy density is too low as is their charge rate examples Toyota Prius - NiMH batteries Nissan Leaf - Lithium ion batteries Chevvy Volt - Lithium ion batteries Tesla - Lithium ion batteries Fisker - Lithium ion batteries VW Electric - Lithium ion batteries Renault - Lithium ion batteries Battery energy density MJ per kilogram Lithium-ion battery 0.720 Alkaline battery 0.671 Nickel-metal 0.28 Lead-acid battery 0.17 IT does the job if you keep it over 50% just like clockwork and can last at least 2 to 5 years without going below 50% charge if you keep them above freezing and below 100 degrees (the same as the Lithiums). I use AGMs on a daily basis and my battery provider says I am the hardest on batteries he's ever seen. I am getting ready to do another build that uses the heavier Deep Cell which is designed to put up with my punishement. But the AGMs are more rugged than the Lithiums that I also use. Nacads also work but for about one run into town before they overheat. Ever seen a Nacad blow up? IT's pretty anticlimatic. They burst and make a mess out of everything around it. And it's caustic. Same goes for a Lithium except they will go into flame and feed the flame until all the liquid is used up. I have never had a case break open on an AGM. I've crashed em, dump em, drop em, used them for Rocky Mountain Offroad, and more. I can see that the Deep Cell Sealed Lead Acid should be as tough and have a longer run time but they are twice as heavy. Which is something of a problem for aircraft The lifespan of the Deep Cell the way I use batteries should be as high as the Lithium and cost less. But the weight means only my 3 wheelers will use them. They just don't make 10 to 15 amp deep cells. But they do make a very solid 35 amp at twice the weight and size of a 12 amp AGM. I am just not sold on Lithiums and I am certainly not sold on Nicads. The Airline Aircraft Industry can use the AGMS and have less problems, almost the same run time as the lower Lithium Mag batteries and save a bunch of money. Airbus use NiCads ,the Boeing 737, 747 (pre-800) and 777 use NiCads , they disagree with you. Keith |
#183
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Is the 787 a failure ?
GunnerAsch wrote:
On Fri, 22 Mar 2013 09:23:17 -0000, "Keith W" wrote: The conventional Batteries are sometimes called Sealed Lead Acid Batteries but they are actually AGM batteries. Modern passenger aircraft normally use Nickel Cadmium batteries Why havent they converted over to NmH? They have a relatively high self discharge rate and can lose up to 20% of the energy stored in the first 24 hours. This is acceptable for hybrid vehicles where the battery is primarily a temporary buffer to capture the energy from regenerative braking but not good for a system intended to initiate an aircraft startup sequence after a week in the hangar. Keith |
#184
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Is the 787 a failure ?
"Mr. B1ack" wrote in message
... Not interested in burning to death over the Pacific .... Better to fall into the South Atlantic because the Airbust didn't inform the pilots that it had stalled. |
#185
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Is the 787 a failure ?
"Daryl" wrote in message
... ...I have never had a case break open on an AGM. Daryl Then you haven't looked very hard. http://nissandiesel.dyndns.org/viewt...60ab1 12d039d "Problem: APC UPSs sometimes have a float charge voltage that is too high and tends to cook batteries. Here's a pair of gel/AGM batteries from a SUA1000 (not an XL) that have swollen so badly that I had to disassemble the case and pry the batteries out of the metal cage: " |
#186
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Is the 787 a failure ?
On Mar 22, 2:55*am, Mr. B1ack wrote:
On Fri, 22 Mar 2013 03:00:07 +0000 (UTC), (Bradley K. Sherman) wrote: Who are you gonna believe, Boeing or your own lying eyes? | | Boeing Co. (BA)'s assertion that U.S. investigators ruled | out a fire within the battery case of a Japan Airlines Co. | (9201) 787 is premature, a National Transportation Safety | Board spokesman said. | | Investigators examining the Jan. 7 fire aboard the | Dreamliner in Boston haven't ruled out that flames erupted | within the lithium-ion battery container, Peter Knudson | said today in response to questions about the issue. | ... | Michael Sinnett, Boeing's chief project engineer, said in | the briefing that investigators hadn't found evidence of | flames within the Boston battery's container box, an | indication it worked as designed to limit damage from a | battery failure. | | A witness who tried to fight the Jan. 7 fire said he saw 3- | inch (7.6-centimeter) flames outside the lithium-ion | battery, and the NTSB has found evidence of high | temperatures within battery cells that failed, according to | preliminary safety-board documents released March 7. | ... http://www.businessweek.com/news/2013-03-15/ntsb-contradicts-boeing-c.... * *--bks * *Gawd ... is THIS thread still going on ???????????/ * *Yes, the 787 is a failure. * *Put it this way ... after hearing about its problems *I* will *NEVER fly on one - ever. I would. Almost every other model airplane has crashed except the 787. Technically, its one of the safest. And I'm hardly the only one who feels this way. Not interested in burning to death over the Pacific .... You won't keep shareholders happy that way !! |
#187
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Is the 787 a failure ?
On 3/22/2013 6:09 AM, Keith W wrote:
Daryl wrote: On 3/22/2013 3:23 AM, Keith W wrote: Daryl wrote: On 3/22/2013 12:55 AM, Mr. B1ack wrote: On Fri, 22 Mar 2013 03:00:07 +0000 (UTC), (Bradley K. Sherman) wrote: Who are you gonna believe, Boeing or your own lying eyes? Boeing Co. (BA)'s assertion that U.S. investigators ruled out a fire within the battery case of a Japan Airlines Co. (9201) 787 is premature, a National Transportation Safety Board spokesman said. Investigators examining the Jan. 7 fire aboard the Dreamliner in Boston haven't ruled out that flames erupted within the lithium-ion battery container, Peter Knudson said today in response to questions about the issue. ... Michael Sinnett, Boeing's chief project engineer, said in the briefing that investigators hadn't found evidence of flames within the Boston battery's container box, an indication it worked as designed to limit damage from a battery failure. A witness who tried to fight the Jan. 7 fire said he saw 3- inch (7.6-centimeter) flames outside the lithium-ion battery, and the NTSB has found evidence of high temperatures within battery cells that failed, according to preliminary safety-board documents released March 7. ... http://www.businessweek.com/news/2013-03-15/ntsb-contradicts-boeing-claim-of-no-fire-in-787-battery --bks Gawd ... is THIS thread still going on ???????????/ Yes, the 787 is a failure. Put it this way ... after hearing about its problems *I* will NEVER fly on one - ever. And I'm hardly the only one who feels this way. Not interested in burning to death over the Pacific .... The conventional Batteries are sometimes called Sealed Lead Acid Batteries but they are actually AGM batteries. Modern passenger aircraft normally use Nickel Cadmium batteries Which are prone to a lot of problems. And it's old tech. Now for the real negatives. If you overcharge them, they overheat. If you let them go down below 20% they will need to be taken out and charged very, very slowly with a special charger. They are very susceptible to temperature ranges. They are the heaviest of the Non Lead Acid batteries, their life span is almost equal to the sealed lead acid if you don't count the fact they damage easy. The cost is more than the AGM. The AGM is just now finding it's way into the aircraft industry. Of course, it has been somewhat over looked because of the Lithiums. But it appears that small aircraft that are worried about initial building costs are not overlooking them. What they are looking at is the replacement hours on the Lithiums. They start out at 800 charges and go to 2000 charges depending on the type of Lithium. The weights in comparison to the AGM is anywhere 3 times to 5 times lighter. But the cost is at least 5 times the cost. Less time between replacements, requires a heated and cooled area but is the most dependable. If that is all that is keeping the 787 from flying, it's a pretty simple fix. Not necessarily as that may need recertification which is a complex and lengthy since the batteries would be heavier and take up more space. They are going to have to be re certified anyway. The AGM isn't that much larger and it's pretty well proven in the Electric Vehicles to day. Most electrical vehicles do not use AGM's, their energy density is too low as is their charge rate examples Toyota Prius - NiMH batteries Nissan Leaf - Lithium ion batteries Chevvy Volt - Lithium ion batteries Tesla - Lithium ion batteries Fisker - Lithium ion batteries VW Electric - Lithium ion batteries Renault - Lithium ion batteries Battery energy density MJ per kilogram Lithium-ion battery 0.720 Alkaline battery 0.671 Nickel-metal 0.28 Lead-acid battery 0.17 The reason the AGM isn't used in larger applications is that it cannot be recharged as it is being discharged. You left out a slew that use Deep Cells. IT does the job if you keep it over 50% just like clockwork and can last at least 2 to 5 years without going below 50% charge if you keep them above freezing and below 100 degrees (the same as the Lithiums). I use AGMs on a daily basis and my battery provider says I am the hardest on batteries he's ever seen. I am getting ready to do another build that uses the heavier Deep Cell which is designed to put up with my punishement. But the AGMs are more rugged than the Lithiums that I also use. Nacads also work but for about one run into town before they overheat. Ever seen a Nacad blow up? IT's pretty anticlimatic. They burst and make a mess out of everything around it. And it's caustic. Same goes for a Lithium except they will go into flame and feed the flame until all the liquid is used up. I have never had a case break open on an AGM. I've crashed em, dump em, drop em, used them for Rocky Mountain Offroad, and more. I can see that the Deep Cell Sealed Lead Acid should be as tough and have a longer run time but they are twice as heavy. Which is something of a problem for aircraft Just leave out that 1 six pack of Tomato Juice to make up the difference. It's not a real problem where an extra 10 pounds is really going to make a difference for something the size of the 787. An added 10 pounds for safety sake is very important. The lifespan of the Deep Cell the way I use batteries should be as high as the Lithium and cost less. But the weight means only my 3 wheelers will use them. They just don't make 10 to 15 amp deep cells. But they do make a very solid 35 amp at twice the weight and size of a 12 amp AGM. I am just not sold on Lithiums and I am certainly not sold on Nicads. The Airline Aircraft Industry can use the AGMS and have less problems, almost the same run time as the lower Lithium Mag batteries and save a bunch of money. Airbus use NiCads ,the Boeing 737, 747 (pre-800) and 777 use NiCads , they disagree with you. Nicads are old technology. The AGM batter is much newer. When they were designing the 737, 747 and 777 the AGMs weren't available. Single Airplanes use the AGMs and that is more critical for weight and safety than the big birds are. I use all these batteries in transporation every day. I am a dealer in the AGMs and the Lithiums as well as the motors and kits. I can also get you a good deal in Deep Cells but the shipping would be a killer. I used to handle Nicads but their output amps were just too low for any of the transport applications. They would get hot and burn out the controller after only a few miles of operation. I'll say it again, after a decade of actually using these batteries, using nicads is too problematic to depend on for safety. And the LiCo battery they used has yet to have an application in transportation because it's just too prone to problems as well. Unlike the Nicad that just gets hot or ruptures with no fire, the LiCo battery bursts into a very nasty bonfire. The safest and most dependable battery for them is still the AGM. Daryl |
#188
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Is the 787 a failure ?
On 3/22/2013 7:22 AM, Jim Wilkins wrote:
"Daryl" wrote in message ... ...I have never had a case break open on an AGM. Daryl Then you haven't looked very hard. http://nissandiesel.dyndns.org/viewt...60ab1 12d039d "Problem: APC UPSs sometimes have a float charge voltage that is too high and tends to cook batteries. Here's a pair of gel/AGM batteries from a SUA1000 (not an XL) that have swollen so badly that I had to disassemble the case and pry the batteries out of the metal cage: " And you haven't seen a burst case either. Bulging, deformed, etc. case but the juice is contained in the case. DAryl |
#189
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Is the 787 a failure ?
On 3/22/2013 6:04 AM, GunnerAsch wrote:
On Fri, 22 Mar 2013 09:23:17 -0000, "Keith W" wrote: The conventional Batteries are sometimes called Sealed Lead Acid Batteries but they are actually AGM batteries. Modern passenger aircraft normally use Nickel Cadmium batteries Why havent they converted over to NmH? The method of charging is more complicated than the other versions. NiMH batteries work well if you only have one cell (say, 12 volt using 4 3 volt cells). But when you are trying to generate 36 volts to 400 volts, each cell pack must be independently charged. Not possible in that application. Actually, it is possible but not practical. As Keith pointed out, NiMH batteries are used in the Prius so it is done but there are better ways today. NiMH batteries were passed over very quickly in almost all applications. Daryl |
#190
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Is the 787 a failure ?
On Fri, 22 Mar 2013 09:22:49 -0400, "Jim Wilkins"
wrote: "Daryl" wrote in message ... ...I have never had a case break open on an AGM. Daryl Then you haven't looked very hard. http://nissandiesel.dyndns.org/viewt...60ab1 12d039d "Problem: APC UPSs sometimes have a float charge voltage that is too high and tends to cook batteries. Here's a pair of gel/AGM batteries from a SUA1000 (not an XL) that have swollen so badly that I had to disassemble the case and pry the batteries out of the metal cage: " Ive seen that happen many times with alarm system backup batteries during the 17 yrs when I was running an alarm co.. Gunner |
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