Ouch, Fred! One of the standard airline emergency procedures for a smoking/burning/fizzing phone or other personal electronics is to submerge it in water or wrap wet towels around it to reduce the temperature and keep it from igniting nearby flammable materials.
It's my understanding that the weakness is more mechanical than chemical. You may know that the insulation within modern Li-Poly (and similar) battery cells is in the order of a few molecules thick. If you could see the insulating layer with your naked eye, such an insulator next to a human hair would have the hair looking like a mountain range by comparison. Once one insulator is breached for any reason, the heat released is usually sufficient to cause other inter-cell insulators in the pack to breach in a cascading effect that releases all the energy within a few seconds, hence the heat and if anything even slightly flammable is near it, flames, smoke and gasses. It all comes down to the care with which the battery was assembled and tested, and the care with which it is used - not overcharging it, not subjecting the battery to excessive shock, etc. While I have some of those batteries in my cameras, personal electronics, etc., they are never stored or charged near anything won't burst into flames even if subjected to molten iron for half a minute or more. A good friend often describes cellular phones as a 'great technology that ALMOST works'. I put modern high-energy capacity batteries in the same category. 73, Ron AC7AC -----Original Message----- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Fred Jensen Sent: Thursday, May 18, 2017 11:05 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] Fire in the house li-ion I was using a tiny Li-Poly pack about the size of a small matchbox that I got from the local RC model store with my KX1 when it began to smoke. Fortunately,I had it on a pigtail, was out on the deck in a Spartan Sprint, and could unplug it and fling it over the railing to the gravel driveway. There were no flames or major explosions, but there were a lot of sparks and quite a bit of smoke for such a small package. The pyrotechnic display went on for perhaps 40-50 seconds, followed by some low-key fizzing and popping. It left a burned mark in the gravel when it was cool. NOTE: This happened while discharging the battery, and I wasn't transmitting at the moment. I struggled through required Chemistry in college, but I did learn enough about that particular column in the Periodic Table to avoid getting the hose. [:-) I have always charged all of my lithium-ish batteries outside from a solar panelso they contain only green and no brown electronsfor events where that matters. I usually put the battery in a metal coffee can. Ibelieve, but do not know for sure, that LiFePO4 chemistry is quite a bit more stable than others. 73, Fred ("Skip") K6DGW Sparks NV USA Washoe County DM09dn ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
