I have x35 (7×5) 18650 lithium ion batteries I’ve ripped from dead laptop battery packs. These batteries were all recharged to a minimum of 1800mAh. So not the best and their longevity is dramatically reduced due to already being hammered.
So what ever I do with them cannot be mission critical, and some got very hot to the touch, so nothing strenuous either…
So what do I do with them? Run an LED light(s), build a portable speaker (I like this one), a raspberry Pi battery power or something else?
What ever I end up doing, it’s going to be new to me and the whole process will be an opportunity to learn.