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Mon Jan 28, 2013, 07:15 AM

Dreamliner: Boeing 787 aircraft battery 'not faulty'

Source: BBC News

Airline safety inspectors have found no faults with the battery used on Boeing's 787 Dreamliner, Japan's transport ministry has said.

The battery was initially considered the likely source of problems on 787s owned by two Japanese airlines.

The world's entire fleet of 50 787s has been grounded while inspections are carried out.

Attention has now shifted to the electrical system that monitors battery voltage, charging and temperature.

Read more: http://www.bbc.co.uk/news/business-21230940

7 replies, 2972 views

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Always highlight: 10 newest replies | Replies posted after I mark a forum
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Arrow 7 replies Author Time Post
Reply Dreamliner: Boeing 787 aircraft battery 'not faulty' (Original post)
IDemo Jan 2013 OP
James48 Jan 2013 #1
Rain Mcloud Jan 2013 #2
Trajan Jan 2013 #4
zellie Jan 2013 #5
Rain Mcloud Jan 2013 #7
IDemo Jan 2013 #6
Omaha Steve Jan 2013 #3

Response to IDemo (Original post)

Mon Jan 28, 2013, 03:36 PM

1. Sooooo

Sooo the Japanese Civil Air Authority has determined that the Japanese made battery
is not the problem....and that it must be the American made batteryu charger that caused
the meltdown.


ok. got it.

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Response to IDemo (Original post)

Mon Jan 28, 2013, 06:53 PM

2. The consensus among DIY EV builders is that BMS

 

or Battery Management Systems cause way more problems than they solve especially if you count vehicle fires as being a problem.
Todays LIFEPO batteries are capable of truly insane energy storage.
A fellow in Ireland tested a single cell in a dead short using an 18mm wrench,the battery was capable of sustained 1500 Amp current discharge while the voltage dropped a mere .4 volts or 3.3 volts sagging to 2.9 volts over the course of the thoroughly unscientific test.

For those shady on power consumption,this is the equivalent of 8 McMansions worth of current with 200 Amp Electrical Service Entries.
I say this is equivalent because the battery started at 2200 amps but settled down to 1500 and the voltage rose from 2.9 EV.
Battery packages can contain up to 100 individual batteries for 338 volts and at dead short 150,000 Amps,your mileage or math may vary.

With this hellacious amount of power on tap,why would you intentionally run hundreds of monitor wires in close proximity to potential short points?
There is simply no way in hell that a printed circuit board can withstand the kind of energy potential latent in these storage systems,so why risk turning it into a ball of plasma that will ignite any matter in close proximity that is combustible under 3000 degrees Fahrenheit?

Now for the disclaimer before i get flamed by Engineers,Journeymen and know-it-alls.
I am not an Engineer and i no longer work in the fields of electronics or electrical supply,commercial,residential or in transportation.
What I am is an amateur or poseur if you prefer,because i have a lifelong obsession with electrically motivated transportation and have been since receiving my first Lionel slot car set for christmas at the age of six.
I love electronics and have successfully hand built my own radio's,motors,guitar amplifiers and effect racks.
I have no credentials worth mentioning,i just thought my two cents would be entertaining.

Here is the latest video from Damien MacGuire in Ireland,Cooking Spanners:[link:|

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Response to Rain Mcloud (Reply #2)

Tue Jan 29, 2013, 02:10 AM

4. Hey there ...

I am a journeyman, certified ET, and have been a electronics technician for 30 years. (JCET for 20 years)

The only problem I see with your 'unscientific' reasoning is this: Power consumption is measured in watts (P=IE), and when we compare house power (200a x 120v = 24,000w) to the available power of this circuit's configuration (1551a x 2.64v = 4095w) ...

Well, the numbers speak for themselves ... The house current is far more 'powerful' from a power 'consumption' perspective ... multiply this by 8 separate house with separate service panels, and we can see that; At 192,000 watts, there is an overwhelming power difference ...

Still .... quite interesting ... Thanks for the link ...

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Response to Trajan (Reply #4)

Tue Jan 29, 2013, 06:45 AM

5. My thought exactly.

 

Lol

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Response to Trajan (Reply #4)

Tue Jan 29, 2013, 05:33 PM

7. Thanks

 

for the correction of my voodoo economics math.

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Response to Rain Mcloud (Reply #2)

Tue Jan 29, 2013, 01:02 PM

6. The Tesla battery management system utilizes many processors, sensors and PCB's

It was originally licensed from AC Propulsion and utilized the same 6,700+ individual Li-ion laptop cells connected together.

http://large.stanford.edu/publications/coal/references/docs/tesla.pdf
The multiple microprocessors within the ESS communicate via a CAN Bus, a robust automotive
communication protocol. During normal vehicle operation and storage, the battery logic board
communicates with the vehicle to initiate battery cooling, report state of charge, and signal
battery faults. A fundamental element of the vehicle and battery pack safety design is the ability
to electrically disconnect the high voltage of the pack from the rest of the car (by controlling two
high voltage contactors) if any of a number of adverse conditions are detected.

The microprocessors, logic circuitry and sensors are continually monitoring voltages, currents
and temperatures within the pack. These sensors also monitor inertia acceleration (e.g. to detect a
crash) and vehicle orientation to the ground (e.g. to detect a rollover). Our battery packs also
include smoke, humidity, and moisture sensors. If certain sensors exceed the specified range,
then the high voltage contactors will immediately (within milliseconds) disconnect the high
voltage of the battery pack from the car. In fact, the contactors are only closed (connected) when
commanded and energized to do so. Without the proper commands these contactors will open.

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Response to IDemo (Original post)

Mon Jan 28, 2013, 10:35 PM

3. Beat me to the post


By two minutes.

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