1st video, Micah allows that he night have rewrapped grade B cells.
2nd video is LiFePO4, off topic.
3rd video, guy is an ass. Waste of time.
GeorgeS first introduced us to the $109 Liitokala 48V15ah 21700 on the forum. He was happy with it, using it sensibly. Gionnirocket bought something similar. He killed it. I knew he would, running an undersized pack on his 750W BBS02. I did the same thing with a $89 Laudation 48V10Ah on my BBS02. They're low end cells, Run them past their max current and they overheat/deteriorate.
I also had ordered the $109 Littokala 21700 pack, but this time I run it like CLark Kent, and it is OK. It's rated at 15AH, puts out maybe 12AH in real life, and that's a fair value, if it don't blow up. I've charged mine about a dozen times. Very light use,
My ideas on battery construction have changed . I haven't seen any of Micah Toll's recent instructional videos, but in his first ones, he glues the cells together. The DIY world has pretty much abandoned that as unsafe. It's OK for the millions of recharegeable cells in your cable modem, but ebike batteries get shaken on bikes, they tip over, and (gasp) even get dropped. Meanwhile, the cheaper chinese packs are glued, and once in a while we read about them going up in flames.