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Boeing lithium batteries

J

Jasen Betts

Jan 1, 1970
0
Yebbut JG did say "By the way, this battery is not as large as for an
electric automobile." Electric automobile ...

Oops. I missed that. Even electric go-karts have larger batteries.

I guess I wasn't really expecting him to say that, why not
compare its size with cell-phone batteries or som other
totally dissimilar application?
 
J

John S

Jan 1, 1970
0
To use a TLJ line from MIB "Try it" -K

I think you are a goddamned idiot who has zero capacity to see the
bigger picture in anything.

Try landing a 100% full to capacity craft of ANY design sans power.

It ain't fun, and you better be the best fucking physicist/pilot there
is. And think on your feet real fast.

Go back to your Balsa wood, rubber band powered gliders, child.

Captain Sullenberger did it on the Hudson without breaking up. Even more
difficult than on a strip.
 
M

MrTallyman

Jan 1, 1970
0
Captain Sullenberger did it on the Hudson without breaking up. Even more
difficult than on a strip.


Did you read up on him?

He was a glider pilot.. an interesting note, since without that
expertise, he would probably not have been so lucky.
 
J

John S

Jan 1, 1970
0
Did you read up on him?

He was a glider pilot.. an interesting note, since without that
expertise, he would probably not have been so lucky.

Indeed. He is a hero of mine. But, I can't speculate on his luck.
 
M

MrTallyman

Jan 1, 1970
0
Indeed. He is a hero of mine. But, I can't speculate on his luck.


OK. What I mean by that is that were it not him, or were it a man
without such a background, THEN we *could* likely speculate on their
"luck", which in instances such as this, tends to refer to "odds".

Any pilot who has flown a heavy, or ay who have flown a plane like the
C-17, with "blown-flaps', would be familiar enough with the "ground
effects" one encounters in those last few hundred descending feet.

The first C-17 test pilots were "astonished" at the difference between
the spot they choose to hit the runway at and where the plane actually
hits being so much different than with a non-blown-flap airframe.

They even used words like "scary".

Someone like that, I would give good "chances" to.
 
Thanks Fred.





"The battery can charge from 0 to 90% in only 75 minutes and comes

with battery management electronics which guarantees multiple levels

of safety features. The rugged prismatic sealed battery design is

capable of withstanding extreme operating conditions far greater than

those normally seen in commercial aircraft operation and requires

absolutely no maintenance."





So much for no maintenance for now I guess.



I am very interested in hearing what they eventually find.



boB

They're not going to find anything. Boeing has been playing with the batteries for at least the past seven years, Yuasa and Saft for nearly 20 years, and the NTSB is using some Navy clowns for SME (subject matter expertise) who cost the government a $500M prototype miniature submarine burned beyond recovery due to Li battery fire that got the whole program canceled. Then of course everyone knows the FAA is less than useless.
 
S

Spehro Pefhany

Jan 1, 1970
0
On Sun, 10 Feb 2013 09:59:38 -0800 (PST), the renowned
They're not going to find anything. Boeing has been playing with the batteries for at least the past seven years, Yuasa and Saft for nearly 20 years, and the NTSB is using some Navy clowns for SME (subject matter expertise) who cost the government a $500M prototype miniature submarine burned beyond recovery due to Li battery fire that got the whole program canceled. Then of course everyone knows the FAA is less than useless.

Interesting. Thanks for the reference.

http://www.navytimes.com/news/2009/07/navy_seal_minisub_072709w/




Best regards,
Spehro Pefhany
 
That is not the only problem,
they have had a cracked window in the passengers compartment,
and a cracked windscreen at the pilot's.
This points to stresses in the composite? body.
Anybody remember 'comet'?
In that time they also tried to make things thinner and lighter,
a bit too thin, and like a comet it fell..
 http://en.wikipedia.org/wiki/BOAC_Flight_781

And Airbus has also problems with cracks in the wings,
some yacht made of composite material just broke into two halves.
Those materials can handle stresses in only one direction.
Bit of turbulence.
Wonder where it will go.

And then there is the stability issue, Boeing had to use active
control of the wings to avoid vibrations caused by airflow.
Of course that works fine as long as all electronics and servos work.

But better is an airplane that is stable all by itself,
and you can land as a glider... when no power.

even with a plane that is stable by itself you are in trouble with
out
power. They are all fly by wire you need power to move the control
surfaces


-Lasse
 
S

Spehro Pefhany

Jan 1, 1970
0
Well, it is pretty obvious they took some shortcuts on this system.
Either they contracted with Thales to torture-test this battery system,
or they should have done it themselves. That would mean thermal
cycling, vibration simulating flight plus takeoff/landing cycles, and
charge/discharge cycles. They also should have done failure insertion
tests to the charge/discharge control systems to deliberately cause
over/undercharge situations that would damage the batteries and see
how they fared.

So, either they didn't do the torture tests, or they didn't do them
for enough cycles.

According to another report I read, another point of contention is
that the safety analysis claimed that a failure in one cell in the
battery would (probably) not affect other cells in the battery.

Turns out it did... the failure of one cell seems to have released
enough heat to compromise the adjacent cells, and the damage
propagated throughout much of the battery.

I have not heard whether the original testing included a deliberate
cascade test (i.e. inject a fault into one cell sufficient to short it
internally, and confirm whether the damage remains contained or not).

Considering the amount of energy that these batteries pack in (NPI)
I'm not terribly surprised that keeping damage contained to a single
cell is difficult.[/QUOTE]

It's dead easy- we do it in some airborne battery systems (not Li) to
prevent thermal runaway from cascading, but it costs some size and
weight.
 
It's dead easy- we do it in some airborne battery systems (not Li) to

prevent thermal runaway from cascading, but it costs some size and

weight.

The fire did not propagate to all the cells. Only one other cell adjacent to the cell originating the thermal runaway burned up, that would make one out of the three adjacent to it. For all they know that cell could have beenin what's called the onset stage of thermal runaway itself, which can lastfor weeks before the internal reactions start to accelerate, and may not be detectable by any of the external sensors.
 
[email protected] wrote:











OK, this is different than what I'd got from some other media, including

some technical sources. They seemed to all say that most of the cells

were severely damaged, and the photos seemed to support that. If only

one other cell had a runaway, then they almost have the protection

right. The cells seem to be pretty closely packed to me, but it does look

like there is some kind of padding between them.



Jon

Right, for the Boston JAL incident NTSB determined the runaway originated in cell 6 and only cell 3 went into sympathetic combustion. The cells were arranged in two columns of four where 3 and 6 were in separate columns next to one another. There are insulator materials can handle temperatures way higher than the 500oC heat of this fire and are quite thin. I'm pretty sure Boeing knows quite a bit about fire containment, just not corrosive electrolyte containment. But then again this fire was extinguished and not allowedto run its course.
 
J

Jeroen

Jan 1, 1970
0
[Lots of double spaced junk deleted...]
Right, for the Boston JAL incident NTSB determined the runaway
originated in cell 6 and only cell 3 went into sympathetic
combustion. The cells were arranged in two columns of four where 3
and 6 were in separate columns next to one another. There are
insulator materials can handle temperatures way higher than the 500oC
heat of this fire and are quite thin. I'm pretty sure Boeing knows
quite a bit about fire containment, just not corrosive electrolyte
containment. But then again this fire was extinguished and not
allowed to run its course.

How do they deal with Li fires anyway? Water or CO2 don't cut it.

Jeroen Belleman
 
J

John S

Jan 1, 1970
0
OK. What I mean by that is that were it not him, or were it a man
without such a background, THEN we *could* likely speculate on their
"luck", which in instances such as this, tends to refer to "odds".

Please supply numbers on the "odds". Or a link thereto.
Any pilot who has flown a heavy, or ay who have flown a plane like the
C-17, with "blown-flaps', would be familiar enough with the "ground
effects" one encounters in those last few hundred descending feet.

I was a pilot. I understand "ground effects".
The first C-17 test pilots were "astonished" at the difference between
the spot they choose to hit the runway at and where the plane actually
hits being so much different than with a non-blown-flap airframe.

They even used words like "scary".

Someone like that, I would give good "chances" to.

Yes, it makes sense that Captain Sullenberger was perhaps a bit more
capable than your average jet jockey. However, landing a glider on a
runway and gliding a heavy jet in for a dead-stick landing onto a river
are not even close to being the same. His margin for error was extremely
narrow. The slightest error in attitude would have caused the jet to
break up.
 
[Lots of double spaced junk deleted...]
Right, for the Boston JAL incident NTSB determined the runaway
originated in cell 6 and only cell 3 went into sympathetic
combustion. The cells were arranged in two columns of four where 3
and 6 were in separate columns next to one another. There are
insulator materials can handle temperatures way higher than the 500oC
heat of this fire and are quite thin. I'm pretty sure Boeing knows
quite a bit about fire containment, just not corrosive electrolyte
containment. But then again this fire was extinguished and not
allowed to run its course.



How do they deal with Li fires anyway? Water or CO2 don't cut it.



Jeroen Belleman

The Logan FD is reported to have used Halon.
 
F

Frank Miles

Jan 1, 1970
0

[Lots of double spaced junk deleted...]

Right, for the Boston JAL incident NTSB determined the runaway
originated in cell 6 and only cell 3 went into sympathetic
combustion. The cells were arranged in two columns of four where 3
and 6 were in separate columns next to one another. There are
insulator materials can handle temperatures way higher than the 500oC
heat of this fire and are quite thin. I'm pretty sure Boeing knows
quite a bit about fire containment, just not corrosive electrolyte
containment. But then again this fire was extinguished and not
allowed to run its course.


How do they deal with Li fires anyway? Water or CO2 don't cut it.



Jeroen Belleman

The Logan FD is reported to have used Halon.

IIRC the electrolyte acts as an oxidizer in a fire. So halon
wouldn't have done much until the oxidizer was depleted. This means
the only way to extinguish a fire in these is to get rid of the heat :(
-f
 
On 2013-02-11 21:56, [email protected] wrote:

On Monday, February 11, 2013 3:25:00 PM UTC-5, Jon Elson wrote:

[email protected] wrote:

[Lots of double spaced junk deleted...]



Right, for the Boston JAL incident NTSB determined the runaway

originated in cell 6 and only cell 3 went into sympathetic

combustion. The cells were arranged in two columns of four where 3

and 6 were in separate columns next to one another. There are

insulator materials can handle temperatures way higher than the 500oC

heat of this fire and are quite thin. I'm pretty sure Boeing knows

quite a bit about fire containment, just not corrosive electrolyte

containment. But then again this fire was extinguished and not

allowed to run its course.





How do they deal with Li fires anyway? Water or CO2 don't cut it.



Jeroen Belleman
The Logan FD is reported to have used Halon.



IIRC the electrolyte acts as an oxidizer in a fire. So halon

wouldn't have done much until the oxidizer was depleted. This means

the only way to extinguish a fire in these is to get rid of the heat :(

-f

Right- they were probably using to prevent fire in nearby objects and it was all they had.
 
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