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So B was aware about battery issues and didn´t communicate this status to FAA since grounding? This is a major topic in finding answers to the system failures. I can´t belive that this comes on top by an insider.
If 150 bat are deep discharged, then the power has gone somewhere. Internal short would destroy the bat and we´d had seen much more incidents and early grounding. So for me it is the surrounding system which is sucking at the bat. |
from hetfield´s link in #523: "We feel good about the battery technology and its fit for the airplane"
:D after 150 dead bats... |
Völlige Ignoranz, sorry.
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It is not necessarily as bad as it may seem. Boeing could have been reporting, and the FAA monitoring. If these batteries were being flagged up by the system as 'below minimum voltage/discharged' and simply being swapped out for new units under warranty, the regulator may have seen the problem largely as an economic one for Boeing. I agree with you though, that such a failure rate should have set alarm bells ringing at both the FAA and Boeing. BOEING should have ask themselves: "What's wrong with the batteries?" |
Please dont laugh at me ... this has been nagging me for the last two days
Maybe not affecting the charging circuits but all that lithium, especially in a composite aircraft |
how many flight cycles have these aircraft done (in peoples opinion) before battery swap? if it is , as mentioned above , 2 or 3 per year - that's really quite low to be swapping batteries!
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At 16K each it must be tempting to try and recycle the batteries that have reached the low voltage cut off?
They aren't talking about 787 batteries but.. How to Awaken Sleeping Li-ion - Battery University Some battery chargers and analyzers, including those made by Cadex, feature a wake-up feature or “boost” to reactivate and charge batteries that have fallen asleep." snip Do not boot lithium-based batteries back to life that have dwelled below 1.5V/cell for a week or longer. Copper shunts may have formed inside the cells that can lead to a partial or total electrical short. When recharging, such a cell might become unstable, causing excessive heat or showing other anomalies. snip A study done by Cadex to examine failed batteries reveals that three out of ten batteries are removed from service due to over-discharge. Furthermore, 90 percent of returned batteries have no fault or can easily be serviced. Lack of test devices at the customer service level is in part to blame for the high exchange rate. Refurbishing batteries saves money and protects the environment. |
So to compare the 78 with the 77, why the need for these batteries in place of the equivalent as used on say the 77?
I am guessing it has an apu and a rat? I am a little confused. |
Pressurization for one. When you have electric supply of air, you don't want to run out at the first hiccup in power supply. The design/certification requires a lot of power, including in the backup system.
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The batteries do not supply power to the Cabin Air Compressors.
Emergency Brakes in the event of a complete electrical failure is the only extra heavy user that the battery is needed for compared to the 777. I think.... |
OK. Thanks
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Inherently unsafe. -Elon Musk, SpaceX, Tesla
Elon Musk, founder of SpaceX and owner of electric car maker Tesla, who should know something about working with these types of batteries, has this to say about a fundamental flaw in Boeing's battery design:
Elon Musk: Boeing 787 battery fundamentally unsafe |
Aus: No batteries at all in the hold
Chuck Norris:
The Australian Civil Aviation Authority recently promulgated a rule banning all batteries, of ANY capacity and ANY chemistry, including Primary (non-rechargeable) batteries from hold baggage. All batteries must be in carry-on luggage, either in their device or packed in an insulating container (paper envelope will do). So in Australia, the answer is "Everyone's airline has banned them." Cheers |
Ferrying a Lithium Battery
If a Lithium battery has never been charged, and is not connected to anything, it would be perfectly safe to transport it.
If it HAS been charged, then it becomes a problem. You can't empty it: a Lithium Cobalt battery will not recover from dead flat. You could pack it in such a manner and such a place that you could ensure that it is disconnected and never gets hotter than 50 degrees Celsius, which would "lessen" the risk that it might spontaneously catch fire, but would not remove the possibility entirely. I suspect the replacements will have to travel by sea (as deck cargo) or rail (but not through any tunnels...) Cheers |
From BBC news
"....Boeing has backed the battery used in the Dreamliner after Japan Airlines and All Nippon Airways said they changed a number of them in the past few months.........Boeing said while the replacement rate was "slightly higher" than usual, the changes were "routine maintenance" ...... On Wednesday, All Nippon Airways said it replaced batteries 10 times over the past few months, while Japan Airlines said it did so in a "few cases" over the past few months. Boeing said that it was carrying out an investigation to find out what caused the battery malfunctions. .....said Mr McNerney, chief executive of Boeing. "We feel good about the battery technology and it's fit for the aeroplane"..... " I wonder why "routine maintenance" has led to "an investigation". And if McNerney and the management team "feel good" about the battery arrangement, I wonder how the Boeing stockholders feel about the management team. |
From BBC news Quote: "....Boeing has backed the battery used in the Dreamliner after Japan Airlines and All Nippon Airways said they changed a number of them in the past few months.........Boeing said while the replacement rate was "slightly higher" than usual, the changes were "routine maintenance" ...... On Wednesday, All Nippon Airways said it replaced batteries 10 times over the past few months, while Japan Airlines said it did so in a "few cases" over the past few months. Boeing said that it was carrying out an investigation to find out what caused the battery malfunctions. .....said Mr McNerney, chief executive of Boeing. "We feel good about the battery technology and it's fit for the aeroplane"..... " BBC News - Dreamliner: Boeing defends 787 batteries I wonder why "routine maintenance" has led to "an investigation". And if McNerney and the management team "feel good" about the battery arrangement, I wonder how the Boeing stockholders feel about the management team. |
Tricky detective work
Just to illustrate the sort of thing that can go wrong (this is NOT a suggestion of what has actually gone wrong), just suppose that the temperature data was output fom the batteries in deg F, when it should have been output in deg C, and suppose that 10 deg C was the minimum operating temperature.
Then the temperature control would be happy to keep the battery above 10 deg F, equal to minus 12 deg C, and the data logged would "prove" that the temperature never went below the limit of 10 degrees. Of course it will not turn out to be anything that simple, but it is an example of how the cause of a problem can sometimes hide the evidence. |
When people are talking about 'defective' batteries and 'new technology', can we remember that the units installed on the 787 are made up of 8 x LVP65 cells which have been used successfully in various applications for nearly 10 years now.
What is 'new' is the installation and the charging/monitoring system that it is hooked up to as well as the loads it is expected to carry. I'm sure that the solution to Boeing's problems will lie in the systems hooked up to the batteries, not the batteries themselves. :ok: |
SOS may well be onto something. If they just ditch the aeroplane bit of the setup the Batteries should work fine. Could save some money in production costs as well.:E
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@SoS
I fully agree...:ok: |
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