Re: Beyond the basics for Li-ion safety?
afaik, the released gasses when venting are not poisonous as such (at least in the low concentrations in this circumstance)
You could try drilling a hole in your light to vent, however this would eliminate any water-proofness, and wouldn't make a huge difference anyway... it might only blow up a little bit, or just shoot a 6 inch flame out the side if it went critical.
There are a few horror stories around, but seriously, there are hundreds of thousands of users of these type of cells, and millions, if not billions of people using lithium-ion worldwide. If it were that common, there would be far more stories to tell.
Check list:
1.) Good quality cells - Doesn't have to be AW, but it also wouldn't hurt.
2.) Good quality charger - Can be a cheapy if you want, but you should be aware of how it works, and how it charges. If it trickle charges, or if it will feed too much current etc. Again, better known brands might be better for a reason.
3.) Get a multi-meter - This is pretty much a "must have" item. Doesn't have to be super expensive, or super accurate, but has to be consistant. Get a baseline of your cells when they have charged (around 4.2V or below) and make sure they aren't going over that level on subsequent charges. If they do, consider step 4.)
4.) Chuck cells when they need to be - If a cell is over charged, or discharged, then get rid of it. If you have charged a cell to over 4.25V then its getting a bit dangerous, and if you over discharge a cell, then it is equally dangerous. Chuck it out, and get a new cell. They are cheaper than a new house.
5.) Use protected cells when possible - If you are new to the game, protected cells can be your best friend. Not only do they have safety features built in for when you are using them, but also when charging your cells. Can include overtemp protection, over charge/discharge, and usually include a vent for gasses.
6.) set up a charging area - a lot of us charge our cells in a metal flame proof box on a cement floor for a reason... if you are charging lots of high capacity cells, then you have higher potential for BOOM. Again, not a mandatory thing, but reccomended you at least get an area that you would consider safe to use
7.) Don't leave your cells unattended while charging. I know its a pain in the *** to charge a pair of 18650's for 5 hours, but if you leave them on overnight, you won't know how they are behaving. You should check for the temperature of the cell itself when charging, and check the charger itself. Expect a bit of warmth (10-20 degrees above body temp) but if it is too hot to touch, you got some trouble!
8.) Use the right cell for the job - if you have a high drain device, consider reading up on, and buying some quality IMR cells, if you need a cell that puts out a lower voltage, consider some LiFePO4 cells. Knowing the chemistry of the cells, and their limitations will make using and caring for your cells easier.
Lithium Ion cells have come a long way in safety, but generally the cheapest cells on the market, can also be the most volatile.
Anything I need to add?