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tekochip
User Rank
Platinum
Re: Risky choice
tekochip   5/31/2013 4:32:06 PM
NO RATINGS
Thanks, I just got back from the specialist and my eyes look really bad, but are fine. You're right, the battery went from perfectly fine to energetic disassembly in, what I wish had been, the blink of an eye. I don't know why some of the lithium burned and some didn't, but since my shirt was covered in the stuff, I'm glad not all of the lithium ignited. Even without the flames, the stuff is very reactive and I have a few chemical burns here and there on my face and neck.
 
It was a sight to behold.


Amclaussen
User Rank
Platinum
Re: Risky choice
Amclaussen   5/31/2013 3:43:10 PM
Tekochip: I am really sorry to read about your personal bout with Lithiums...

But on a lighter side, as they use to say: "Welcome to the wonderful real world of lithium batteries, please fasten your seatbelt and HOLD-ON!"

In other posts I have already mentioned the frequent, dangerous skirmishes that electric model airplane fliers currently have with Lithium batteries, both lithium-Ion and Lithium-Polymer types.  I can vividly remember a couple of cars completely burned to ashes when two fellow modelers left a Li-po pack quietly charging inside their vehicles and went happily flying other models.  There are even small companies that sell strong, thick walled ceramic pots that are able to contain a small battery fire inside!.

In one of those two cases, I can personally attest that the charger used was a very higHly regarded, intelligent type, that had all kind of protection against overcharge, overcurrent, batt overtemperatures, short circuit, inverted polarity, etc. That battery was apparently sane, and had been used about half an hour before the fire without any sign of trouble. It just decided by itself to go wild!

Most commenters have never witnessed a lithium batt mishap actually.  I'm sure your engineering criteria and appreciation of their sometimes bad manners have been painfully enhanced with your experience.  Fortunatelly you are well and in one piece, and your shop is still there.  In a way you benefitted from this direct, hands-on, real experience; so NOW you are qualified to teach others something!  Best wishes.  Amclaussen.

notarboca
User Rank
Gold
Re: Risky choice
notarboca   5/31/2013 3:19:56 PM
This is indeed risky business. Not sure I'd want the equivalent of a fire bomb secured anywhere near my position on the ISS.  The volitility of lithium, and its ability to produce its own oxidizer, possible overpressure within the battery container, etc.  I hope they will do extensive tests before making this an operational situation.

far911
User Rank
Silver
Re: Risky choice
far911   5/31/2013 3:07:12 PM
NO RATINGS
@Ann - Don't you think it was completely useless to shell out these resources in situations where there's plenty of sunlight at the disposal of solar panels. Seems like a bad idea from the get go, don't you think? 

Amclaussen
User Rank
Platinum
Re: Risky choice indeed...
Amclaussen   5/31/2013 3:00:52 PM
One reflection on the words used by Elizabeth above ("gutsy")...
I believe one of wrong things in engineering, is adopting that complacent posture: "I hope it will be OK" "I hope it doesn't break", "I hope it does not blow out..." etc.

I concur with your assessment that the chemistry and type of battery is RISKY, where I don't agree is with the "gutsy" part.  Too many bad things have happened when engineers start using "guts" as inspiration. Fortunately, it appears the only thing they are risking here, is a lot of money, in case the batteries go bad.  Since Yuasa has sold a lot of its batteries to be used in satellites, apparently without mishap.  But those same batteries failed miserably on the Dreamliner... go figure.

As I tend to be cynically esceptical towards design, I always try to assume worst case scenario to analyze my design decisions.  That has proved to be much better in the long way, than to hope for the best.  Technology accidents are one of my favorite reading too, because they ruthlessly show engineers how wrong we are sometimes, and being modest and humble avoids becoming too confident and prone to seed a failure into the design process. Cheers, Amclaussen.

kenish
User Rank
Platinum
Re: Risky choice
kenish   5/31/2013 2:52:42 PM
Glad you're fortunately OK.

Taking a step back as engineers, there are numerous other energy sources and loads that have a much higher energy content per mass or volume, and are just as volatile.  The thousands of gallons of jet fuel on the 787 and the thrusters on the ISS come to mind.  Energy-dense solutions are required whenever mass and volume carry big penalties.  The risks have to be mitigated down to an acceptable levels.

kenish
User Rank
Platinum
Re: Risky choice
kenish   5/31/2013 2:45:13 PM
Agree with your comments, but the Boston incident was Japan Airlines while the emergency landing was All Nippon Airways.  That tends to rule out a service issue that was unique to either airline.

Ann R. Thryft
User Rank
Blogger
Re: Risky choice
Ann R. Thryft   5/31/2013 12:28:50 PM
Even using these batteries on unmanned satellites makes no sense, considering how much time, energy and dollars NASA spends on figuring out how use less fuel, utilize solar panels, and incorporate composites, all to make it possible to load on more expensive instrumentation. These aren't exactly cheap, either.

Jim_E
User Rank
Platinum
Re: Risky choice
Jim_E   5/31/2013 11:55:50 AM
NO RATINGS
Phil, thank you for the clarification.  It sure doesn't sound like a good idea to use this battery pack on the ISS!

Hopefully it's a battery pack that's similar to the 787 battery, but with a better design.

Phil Pearce
User Rank
Silver
Re: Risky choice
Phil Pearce   5/31/2013 10:55:50 AM
Jim, during thermal runaway in a Lithium-ion battery the cathode generates its own source of oxygen therefore combustion can occur even if the battery is mounted outside of the ISS.

I cannot understand NASA'S decision in employing Boeing's technically incompetent solution to resolve the Dreamliner's battery problem.  Boeing's solution is to encase the 787's batteries in a stainless steel enclosure and hope for the best rather than preventing thermal runaway from ever occurring in the first place.

phil.pearce@ieee.org

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