Hi all
I'm very busy at the moment, so I haven't been able to check CPF for a while. Looks like there has emerged a whole new discussion within this thread.
The thing is, folks, Li-ion cells can be very dangerous. That is an irrefutable fact. If you think li-ion cells cannot pose any danger, you don't know what you're talking about. It's that simple.
The key word here is "can". When lithium cells are treated the way they are supposed to be treated, they are not dangerous. That is why there are millions of consumer electronics which run on li-ion cells used daily without any accidents. The manufacturer designs a device and designs a battery pack to go with it. As long as the proper pattery pack is used in the proper device, the manufacturer controls every single step: the power source, the charging algorithm, the maximum charging voltage and current, the maximum discharge current, the overdischarge protection, the quality of the components, the various safety measures, the capacity and quality of the cells, the packaging ... Basically, he can make sure himself that every single component is a perfect match for the cells and the rest of the device, be it an MP3 player or a laptop. That is why he will sell you a li-ion battery pack for your laptop: because he knows he did everything right himself and nothing will go wrong as long as you don't tear the battery pack open and start playing with the individual cells and putting them in different chargers and making a charger out of a mobile phone / laptop / power supply / circuit of resistors (like a lot of people do here on CPF). Those are all things which can be done without accidents, but they all require a level of knowledge far above that of the regular consumer.
Now, when you start playing with loose cells, the manufacturer has no control whatsoever about the way the cells are used. He does not want the responsibility of selling loose li-ion cells to regular people who don't know what they are or how to use them, so he won't sell them at all. Remember, whe are putting loose cells in flashlights, often in series, often without protection circuitry, often draining the cells near or over their maximum rated current. This is "edgeplay", as you could call it: we are pushing the boundaries of safe behaviour. Having to carry responsibility for that is the nightmare of every battery manufacturer. That is the reason he only sells battery packs and not loose cells. People are stupid and careless, and he knows carelessness will cause serious accidents with li-ion cells. It WILL cause serious accidents. No "can" this time. Ignorance and carelessness go hand in hand (and expertism and carelessness sadly do too) and they don't mix with li-ion cells without catastrophical consequences.
My first post tells nothing but the truth. Li-ion cells are dangerous when used improperly but when you do what I write in the first post you will not have a problem. Remember people, the average IQ in the western civilization is 100. Everybody with any form of higher education (post high school) has at least 110-120. Most members of CPF have an IQ above 100. However, that means there is an equal number of people who have an IQ (sometimes far) below 100. Those people have an internet connection too, and most of them can read and use a credit card, which makes them capable of buying and mistreating li-ion cells. I sincerely hope my first post scares away everybody who is not intelligent enough to use li-ion cells in a safe manner. I think it does, and that is part of what it is intended to do. I'm not going to put a number on who is and who isn't intelligent enough because common sense is not measured in an IQ test so a 90 can have it while a 110 can lack it. When I consider all the kinds of people who can read this thread: child, elder, dumb, smart, male, female, factory worker, deskjob, tradesman, nanny ... I can tell myself honestly that any of these who follows my advice will not have an accident. Some people think they can be safe with less safety measures. If you think you can, feel free to do so, but it is entirely your own responsibility. I am not an expert, but I know for a fact that the advice in my first post is sound and will prevent accidents. And anybody who is heavily overwhelmed and scared away from li-ion cells by my first post shouldn't be using loose li-ion cells anyway.
I don't have the time right now to join the discussion about what is and what isn't safe with li-ion cells and packs etc, althoug it is a very valuable one, but now you know why I stand by my first post and will not lighten it.
