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-   -   Poll: lithium-ion batteries used in a plane (http://www.diyaudio.com/forums/lounge/227973-poll-lithium-ion-batteries-used-plane.html)

agdr 16th January 2013 06:50 PM

Poll: lithium-ion batteries used in a plane
 
In the news lately is the use by Boeing of lithium ion batteries in the design of their new 787 Dreamliner and some fires/failures. Here is an article that sums things up and has a picture of a burned out lithium battery pack from the plane:

Mayday for Dreamliner: The Airplane?s Woes Explained - The Daily Beast

The folks here know a lot about batteries. Lithiums save weight with their high energy density. The Dreamliner is all about being light for fuel economy. But lithiums may also be riskier than some other battery types.

So the poll is... lithum-ion batteries in a plane that makes trans-ocean flights: smart move to save weight, or too risky?

Disclaimer: I have no involvement with either the aircraft industry or the battery industry. Just curious given the news item.

Also if anyone here has some knowledge of plane electronics, given the increased use of electronics in planes now, I'm wondering if they include a halon (or other) fire suppression system in these electronics bays in the planes? Similar to what is used in computer data centers:

https://www.youtube.com/watch?v=2fyGGqgVzCY

dmills 16th January 2013 07:45 PM

Lithium is a very light battery technology but it does have its share of problems, and a tendency to 'thermal dissasembly' is probably formost amongst them.

That said, with good quality cells this only happens if the pack is abused (Thermal problems, over charge or discharge), but you would want to do a lot of qualification work on any pack you were proposing to fly, including such things as exploring as many of the interesting bits of the vibration/temperature/pressue/load/state of charge state space as possible.

Given this pack is allegedly basically an APU starter battery I would also be looking long and hard at fuel savings over aircraft life Vs cost to do that qualification work, it is not immediately clear that the lithium pack (Plus its rather critical protection systems) is a sufficiently big saving to justify the costs.
Lithium has a nasty trick in which it gets hot and burns hours AFTER it was abused (Seen that happen), something like a charge regulator fault or possibly even starting the APU with a flat battery (Lithium is funny that way) would do it.

I would personally not be reading too much into these stories about a very new aircraft with a LOT of new technology, the A380 (In many way a less cutting edge beast) had a raft of issues that eventually got sorted (As did the Rolls Royce engines a few years back), this will get investigated and changed so as to make it work.

Regards, Dan.

Wavebourn 16th January 2013 09:06 PM

Hey, after this thread TSA may ban all cellphones and other electronic devices on planes because they contain Li-ion batteries. They already ban liquids because they may be combustive!

http://www.youtube.com/watch?v=bZ8IsMRFM5o

http://www.youtube.com/watch?v=pizFsY0yjss

agdr 17th January 2013 01:39 PM

I ran across a NY Times article with some more technnical details:

https://www.nytimes.com/2013/01/17/b...pagewanted=all

Sounds like they really went to Herculean efforts to mitigate the risk! Boeing really wanted that battery. Venting any smoke to the outside and trying to encase it so it could burn and not affect the plane. Plus some sort of auto-disconnect system. Will be interesting to see if it all winds up being enough. From the article:

Mr. Sinnett [Edit, Boeing Chief Engineer] said that if the lithium-ion batteries started a fire, it would be nearly impossible to put out because the batteries produce oxygen when burning. Mr. Sinnett said that the plane was designed to survive such an event in flight, when the cabin’s air-pressure system protects passengers and allows the plane to vent the smoke outside. The plane is also designed, he said, to contain a fire to a small area.

“Fire suppressants just won’t work on a situation like that,” he said in the conference call. “So something like that is very difficult to put out.”

Heat from the fire on the plane parked in Boston last week was so extreme that it melted the bolts holding the battery to the equipment rack. Firefighters had to use a hydraulic tool to cut it loose.

alexberg 17th January 2013 11:52 PM

That's funny. People from USSR by descend would LOL.
I always thought that only one nation can create the problem and only then put a heroic effort to mitigate it. Seems like globalisation to me.
They probably saved few pounds by not using proven MeH batteries.
All that needed by now is pressure capable vessel with pressure relief valve made of quater inch stainless steel. Question remains where to get the power when the battery dies: from the next same one installed for redundancy ;)
EDIT: Is it due to the plane not being civil derivative of the real one or it's just a new generation of engineers/managers who forgot the lessons learned hard way by older peers?

agdr 18th January 2013 08:28 PM

Yeah, I agree, just from the news accounts it seems like the NiMeH would have been a good chioice. The weight of that explosion-proof box probably cancels out whatever weight savings they had from Li-Ion. I was reading today that one or more of the hybrid car manufacturers have gone to the safer but less energy-dense LiMN chemistry.

One thing is likely - if they have to change battery chemistry it won't fit back into the same hole in the electronics bay.

bart_dood 18th January 2013 08:33 PM

I find it funny people get all worked up about batteries when they are sitting in a thin walled aluminum can at 500mph loaded with tons of highly combustible explosive hydrocarbon fuel!

agdr 18th January 2013 11:55 PM

Lol!! How true. :)

alexberg 19th January 2013 12:48 AM

Stainless steel envelope
WAS A JOKE like ZEPPELIN made of lead
even with one it is really hard to contain - auto guys tried it in an early days of LiIon - it inflates like like latex air balloon...
In regard to flying on/inside a fuel tank - you won't put a ignition device into that can, would you?
Most vehicles have emergency fuel dump system - rarely used in the air - usually pane flies in circles till all fuel is consumed - again due to the fire hazard

Charles Darwin 19th January 2013 12:43 PM

Quote:

Originally Posted by agdr (Post 3329931)
I ran across a NY Times article with some more technnical details:

https://www.nytimes.com/2013/01/17/b...pagewanted=all

Sounds like they really went to Herculean efforts to mitigate the risk! Boeing really wanted that battery. Venting any smoke to the outside and trying to encase it so it could burn and not affect the plane. Plus some sort of auto-disconnect system. Will be interesting to see if it all winds up being enough. From the article:

Mr. Sinnett [Edit, Boeing Chief Engineer] said that if the lithium-ion batteries started a fire, it would be nearly impossible to put out because the batteries produce oxygen when burning. Mr. Sinnett said that the plane was designed to survive such an event in flight, when the cabin’s air-pressure system protects passengers and allows the plane to vent the smoke outside. The plane is also designed, he said, to contain a fire to a small area.

“Fire suppressants just won’t work on a situation like that,” he said in the conference call. “So something like that is very difficult to put out.”

Heat from the fire on the plane parked in Boston last week was so extreme that it melted the bolts holding the battery to the equipment rack. Firefighters had to use a hydraulic tool to cut it loose.

That venting to the outside doesn't seem to be working as planned since one of the 787s did an emergency landing after the pilot smelled smoke in the cockpit.


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