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Boeing warned in 2006 about dangerous 787 batteries
Amazing power struggle behind closed doors comes to light and surely attracts lawsuits about wrong doing. (www.aero-news.net) More...Sort type: [Top] [Newest]
This is what I wonder also. The Li-ion battery that caught fire in the Boston incident was about a cubic foot in size and could be easily carried under the arm. This is the battery that supplies the APU. How many other batteries are there like this on the a/c as part of the "main ship" supply"? Even at half the weight of the safer NiCad it seems to me the weight savings would be negligible. I understand that manufacturers need to find weight savings everywhere but to take this kind of risk to save a few hundred pounds seems crazy.
lion batteries are everywhere. in laptops, cell phones, tablets, etc. i have searched the web and have found not one lion pack has exploded, caught fire, etc in the past two years. the original issue with the lion was that system designers assumed that the lion was like any other battery. so just shove a bunch of volts and amps into them and all should be fine. well, it obviously wasn't. with the advent of proper safety and charging systems, this issue is pretty much a thing of the past.
until now !! what is needed now are cool heads, like those who contribute here, examining all aspects of the issue and contributing there thoughts.
what doesn't help is the self styled experts jumping into the conversations with statements like
"Quoting sources that would speak only on the condition of anonymity"
or that the battery in the boston incident "exploded causing severe damage to the airplane"
or my favorite,
"Securaplane's main buildings were burned to the ground when a battery test went wrong"
what they don't say here is that "an investigation into that fire determined the cause was the set-up of the test, not the design of the battery or the charger."
looking at the systems in the 787, the safety circuits and the charge controllers appear to be properly designed and should be making the packs safe. so, in my mind, the issue has to be the construction of the battery pack itself.
what is different? the battery is vented overboard. is there an issue with the cell construction that caused the cell cases to expand and contract, possibly wearing away some of the insulating materials and causing a short?
when the cell is constructed, is there an air bubble between the plate and the separator that expands and contracts with changes in pressure brought about by changes in altitude, which wears a small hole in the separator, causing a short?
is it the loads of takeoff and landings, deforming the cells and again causing internal shorts? or both? or something else?
could the fix be something simple like building shelves to allow the cells to stand on end rather than on their sides so the cell cases don't flex as much? or liquid cooling systems that keep the cell temps at about 100 degrees F (37deg C)?
???
until now !! what is needed now are cool heads, like those who contribute here, examining all aspects of the issue and contributing there thoughts.
what doesn't help is the self styled experts jumping into the conversations with statements like
"Quoting sources that would speak only on the condition of anonymity"
or that the battery in the boston incident "exploded causing severe damage to the airplane"
or my favorite,
"Securaplane's main buildings were burned to the ground when a battery test went wrong"
what they don't say here is that "an investigation into that fire determined the cause was the set-up of the test, not the design of the battery or the charger."
looking at the systems in the 787, the safety circuits and the charge controllers appear to be properly designed and should be making the packs safe. so, in my mind, the issue has to be the construction of the battery pack itself.
what is different? the battery is vented overboard. is there an issue with the cell construction that caused the cell cases to expand and contract, possibly wearing away some of the insulating materials and causing a short?
when the cell is constructed, is there an air bubble between the plate and the separator that expands and contracts with changes in pressure brought about by changes in altitude, which wears a small hole in the separator, causing a short?
is it the loads of takeoff and landings, deforming the cells and again causing internal shorts? or both? or something else?
could the fix be something simple like building shelves to allow the cells to stand on end rather than on their sides so the cell cases don't flex as much? or liquid cooling systems that keep the cell temps at about 100 degrees F (37deg C)?
???
The main purpose of aircraft battery is to supply power to the aircraft in emergency situations. On the aircraft that I'm very familiar with, the on board battery is used to start the APU which once on line, supplies power to the aircraft. There is almost no load on the battery unless all other generator power is lost and power is required to operate the aircraft systems.
Interesting to read the comments; sounds like a classic case of cutting quality corners to meet time and cost targets. I get frustrated when I discover this in my factory ... but I'm not developing or manufacturing tin cans that carry hundreds of human lives from point A to point B! Call me naive but I'd put quality (safety) pretty high on the priority list!!!!!
What puzzles me is that there is plenty of room in the airplane, and the battery weighs only 60 odd pounds, why not use old nicad? It would be double the size and weight, but how much of a fuel penalty could that cost? I bet less than 50 planes parked in the sun.
Ah well, just another law suit around the corner.