(I would greatly appreciate it if some clarification can be provided on what I said wrong, as I regularly deal with 21700 li-ion cells and likely will deal with

(I would greatly appreciate it if some clarification can be provided on what I said wrong, as I regularly deal with 21700 li-ion cells and likely will deal with more, and I’d like to do so safely. I’m assuming I was downvoted because I said something wrong, which in the world of lithium batteries, can be quite dangerous.)