I'll just jump in with my two cents on this discussion. I'm a licensed, registered fire protection engineer, also licensed in mechanical and electrical engineering. I'm not a battery expert but I hope I know enough NOT to be dangerous. Fire protection of all these new sorts of batteries is a rapidly emerging (and often confusing) challenge, but if you think about the science and physics of what these mighty little power packs are, you should realize that they contain a lot of potential energy in their chemical contents and it's designed to be released in a steady and more or less linear fashion, and that's why they're so compact and useful. What we sometimes think of as increasing the safety of using and storing them can sometimes defeat our purposes. For example, storing them in a traditional flammables cabinet (oftentimes sharing the same cabinet with cleaning fluids, alcohol, and even gasoline!), we can create a highly explosive environment inside the cabinet if a stored battery isn't happy inside the cabinet. And just because some types of batteries don't ignite when they begin to go into thermal runaway, the smoke that they emit can still be an explosive and toxic mixture of chemical compounds that are plenty dangerous in themselves, even without ignition or flame. In thermal runaway, ventilating the gases that are generated by batteries is important to reduce the hazard that they create. In short, they should all be treated with respect and we should be aware that it's not only overcharging or overheating them that can set off thermal runaway... physical damage, including striking them, dropping them, or puncturing them can also initiate the chemical process if the separator between the anode and cathode is compromised, and in those cases it can develop slowly over hours or even days. Using batteries that aren't tested, listed, and labeled by one of the alphabet testing labs means that you have no idea how well they are designed or which standards that they meet, if any. Or what their expected quality control for failure rate is, right from the factory. And it's not just dead batteries that we need to worry about, because the higher the state of charge of these batteries, the more energetic can a thermal runaway be if it gets started. Just sayin'. Oh, and Larry- thanks for bringing so much useful information on this to the Net!
Oscar Zuniga Medford, OR
-- KRnet mailing list KRnet@list.krnet.org https://list.krnet.org/mailman/listinfo/krnet
