Several posts had issues with the manufacturer being trustworthy. IF the CE certificate at the bottom of the product page is authentic, I would say they are legitimate because they took the time and paid the expense to go through the certification process to help gain access to the European market. Can anybody fake this certificate? YEP. Is it fake? You tell me.
Well adding onto this, my understanding of these certifications is that they apply to the product line.
I.E. some samples get sent away for testing and if they pass, all Brand ABC, Model 123 cells are "CE certified" or "UL listed" etc. Or best case scenario samples of each production batch are tested (but i'm not sure this is true).
Point being its not individual testing, so I believe products could have legitimate CE or UL certifications and still be grade B, grade C, or other less than A grade cells. And its important to remember the companies we buy these cells from are (sometimes 'grey market') resellers, and therefore did not pay anything for certifications and don't risk losing their certification or harming their brand in the same way that the manufacturer does. I do believe these certifications give some confidence that the manufacturer is legitimate and stands behind their product, but I'm not sure that can be extended to resellers or individual cells.
I don't know much about CE but I believe for the UL certification most of the tests pertain to things like will it explode, will it catch fire, will it fail safely, etc, and not whether the product is usable, is within the stated specs, etc.
I have little doubt that CATL cells are legitimately CE certified, but I'm not sure how much significance that has to quality of grey market cells with scratched off QR codes being sold by an unaffiliated reseller
I'm not saying these are bad cells, they very well might be great cells, or more likely solidly usable grade B cells or older Grade A cells that aren't quite good enough for an industrial setting but would be just fine for most DIY use cases.
I also want to reinforce that I don't know a ton about these certifications, I've done a tiny bit of research, but my understanding is still very vague and limited. Don't take my word for any of this. Here is a
short primer on different relevant certifications, and here is a
little more in depth explanation of CE and UL.