Myself and a few other chemists decided to do a little "experiment" with Li-ion batteries. Connected a few laptop and mobile batteries in series and then deliberately shorted them. We managed to get a thermal runaway and ignition. Wasn't spectacular, but when we put it out with CO2 it did reignite. We then tried dry ice, and that put it out but it reignited, we did know the answer which was to quench it with loads of water, which of course worked.
Only problem with this on board an aircraft is that;
a) You don't really want water sloshing about in an electronics bay, and unless you are refilling distilled water every turn around then there will be ions present, hence conductive.
b) The water will react with the Li, forming hydrogen, now that's OK in my back garden, probably not so great in an enclosed space with electronics in it.
As for Halon, I don't know, problem is that isn't it banned, and also there is no use in inerting the compartment as Li batteries have their own oxidizing agent. I'd love to give it a go in the lab though.
Conclusion - I won't fly on an A/C with Li for quite a while
Last edited by Ex Cargo Clown; 15th Jan 2013 at 19:43.