Very Interesting John. Think there was article on new battery technology in Jan 12 in soaring cafe.
CASA have a poster (think at some airports) on carriage of Li batteries on RPT a/c and seem to remember you can carry more in cabin than checked in baggage but by the way it is worded I defy anybody to work out what the legal limit is. They make no mention of Lipo safe bags which the model people all seem to have. Ian McPhee On 25 February 2013 22:30, John Parncutt <[email protected]> wrote: > All battery systems pose a potential fire risk especially if short > circuited, this is why it is essential to provide a suitable fuse as close > to the battery terminal as possible.**** > > ** ** > > Due to their potential to provide high amounts of discharge current > Lithium batteries will generate a great deal of heat if shorted and > certainly become a major fire or even explosion risk. If a cell or the > battery develops an internal short (before the terminals) then no amount > protection in the way of external fuses or circuit breakers will be > effective.**** > > ** ** > > All new battery technology seems to go through this problem, I can well > remember major similar issues with Nickel Metal Hydride batteries a couple > of decades ago. **** > > ** ** > > I believe in the long term Lithium technology especially some of the newer > Lithium Phosphate variants will replace the >150 year old lead acid > technology completely (much in the same way as LED lighting is rapidly > replacing both incandescent and fluorescent lighting). **** > > If you consider the huge amount of lithium batteries in use in mobile > devices ranging from portable tools through to laptops, phones tablet PC’s > and now electric cars, and the relatively rare event of fires caused by > these devices then I think it puts the situation into better perspective.* > *** > > ** ** > > One of the major differences in battery usage in a commercial airliner as > opposed to a glider (apart from the obvious size of the batteries!) is that > the airliners systems are designed to charge the batteries in flight. We > would generally charge our batteries in the hanger (unless you have solar > panels on the fuselage), And as far as I understand the charging process > is where a significant amount of the overheating problems have occurred. * > *** > > ** ** > > I think Airbus is being justifiably prudent given the recent incident with > the Boeing 787. However I think with pressure from the aviation industry > that battery manufacturers will rapidly further develop their > manufacturing processes and fine tune the chemistry, and Lithium > technology will win out.**** > > ** ** > > As far as our own pastime is concerned, I have been evaluating Lithium > Phosphate Batteries manufactured by Shorai in Japan. These are marketed as > a replacement 12Volt motorcycle battery. I have conducted discharge tests > at fixed current rates (generally 2 Amps) using a commercially designed > computer based battery testing system, whilst the manufactures stated A/H > capacity is somewhat overstated, the ability of the battery to provide a > constant voltage throughout the discharge period (>12V) is significantly > better than that of its lead acid counterpart. Couple this with the reduced > weight and expected longer life then this becomes an interesting option as > a Glider battery.**** > > ** ** > > By the way throughout the testing I have at no stage found any evidence of > abnormal heating of the battery.**** > > ** ** > > I have personally used the Shorai battery in flight several times, but > given the concerns of the aviation industry in general have held off > recommending that our club converts its fleet to this technology in the > short term. I believe that it will only be a couple of years before this > technology full acceptance in the aviation industry.**** > > ** ** > > **** > > ** ** > > ** ** > > John Parncutt**** > > **** > > ** ** > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Craig Vinall > *Sent:* Monday, 25 February 2013 9:04 PM > *To:* [email protected] > *Subject:* [Aus-soaring] AIRBUS has abandoned its plans to use > lithium-ion batteries for its new A350 airplanes**** > > ** ** > > Thought this may be of interest. I know that these batteries are becoming > popular in gliders; what do others think? Is there a potential fire risk?* > *** > > **** > > *AIRBUS has abandoned its plans to use lithium-ion batteries for its new > A350 airplanes.***** > > The European aerospace group said Thursday it would revert to conventional > nickel-cadmium batteries for the A350 due to the uncertainty surrounding > the technology following the grounding of Boeing's 787 Dreamliner. The A350 > is a wide-body long-range jet rival to the 787 and is expected to make its > first flight around the middle of the year.**** > > Airbus says it does not expect the battery switch to delay the A350's > schedule.**** > > Lithium batteries are lighter and can store more energy than other types > of batteries of an equivalent size, and manufacturers view them as an > important way to save on fuel costs. But the batteries are also more likely > to short circuit and start a fire than other batteries if they are damaged, > if there is a manufacturing flaw or if they are exposed to excessive heat. > **** > > Federal officials grounded the 787 last month because of problems with its > lithium-ion batteries that caused one fire and forced another plane to make > an emergency landing.**** > > "Airbus considers this to be the most appropriate way forward in the > interest of program execution and A350 XWB reliability," spokeswoman Mary > Anne Greczyn said.**** > > Airbus noted the A350 uses batteries in a different setup than the 787, > making it unlikely that it would face the same problems. Its A350 > flight-test program would still go forward with lithium-ion batteries.**** > > But because the causes of the problems with the 787 batteries remain > unclear, Airbus decided to make the switch "to optimise program certainty," > Ms Greczyn said. Airbus is a unit of Netherlands-based EADS NV.**** > > *The Wall Street Journal* first reported on Airbus' decision to drop the > lithium-ion batteries, noting the incidents with the 787 have led to > industry uncertainty about future safety standards for the technology.**** > > Regards**** > > **** > > Craig Vinall**** > > _______________________________________________ > Aus-soaring mailing list > [email protected] > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring >
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