A related problem just hit me this weekend. I had removed a failed/bulged Lithium Ion battery from a week ago and placed it with my others to be taken during t

A related problem just hit me this weekend. I had removed a failed/bulged Lithium Ion battery from a week ago and placed it with my others to be taken during the one time a year that garbage collection allows us to bring the toxic stuff to them for recycling (later this year...). Fast forward to this week and the battery is nearly twice its size. A while back I decided to repair a bunch of failed Ryobi Li-Ion packs (taking them apart, testing the 18650 cells independently and rebuilding each with all new cells of the same specifications)[0]. I'd done this several times over the years with various battery packs made up of 18650 cells[1]. While basically ignoring all of the intelligent warnings for handling/dealing with these cells[0], I managed to short one of the visibly bad cells for long enough to turn the battery into what might be a very respectable, completely out of control, blow torch. The heat from the flame caused me to immediately drop it and everything I was holding but despite being in my hand for all of maybe 10 milliseconds, it managed to leave a permanent scar (which serves as a reminder for me every time I decide I'm going to risk my limbs to save a few bucks to ... at least ... be a whole hell of a lot more careful). My question is: what in the hell do I do with this expanding pouch battery? I can't take it to the "toxic waste day" event until the fall. I know these pouch batteries are as prone to torching as much as the 18650 cells and this one is growing so fast that it was noticeable. Are there any options beyond: (a) Toss it in one of the "Electronics Recycling" boxes at a big box store (are those still a thing?) -- I am concerned for the safety of the staff/store. (b) Same but get one of those "mail away" bags -- I would never do this; trading a garbage truck fire for a mail truck fire isn't an improvement and I'm sure it's as illegal as: (c) Hide it in the garbage and hope for the best -- see the article and "b" for why I won't do this, either. And finally, the only option my garbage carrier gives me: (d) Find some magical way to store this thing until the fall when my garbage carrier will let me drive it to their facility for Toxic Stuff Day. By then it'll be in a box of melted goo. For the moment, I went with (d) and placed it inside of a container from a kiln I hacked together a few years ago ... which sits in the center of the cement floor of my shed[2]. I don't like any of these options -- anyone else been in a similar spot and found a good solution? [0] I am not a battery guy or an electrical engineer, just a typical hacker with the driving force being: "What could possibly go wrong?" [1] Pretty much every notebook from that era (gifted to me as "I'm just going to throw this out, do you want it?) had detachable packs made up of combinations of 18650 cells wired together. [2] I learned I built this pretty well after it took a real world test with some mixed molten metals and other materials that left the entire interior covered in a layer of black "something" but did no damage otherwise.