This is a spanish guy who built his own off-grid setup with solar panels and 18650 batteries. As a complete ignorant in electric stuff to me this is amazing. If you know some spanish you can find here a good channel IMO!
Those cells are very dangerous to use. stick to LiFePO4 or LTO. Cobalt based chemistries can experience and awful thermal runaway when over charged. This can occur if you have a shorted fet in your BMS. Which can happen from inrush current or high voltage.
https://www.youtube.com/watch?v=u3LgbTsIO3A