Some of them will be tough to know. For the mainstream sizes, like 18650 and 21700, one can probably figure it out by comparing discharge curves to well-known models of similar ratings.
Other sizes tend to be made by smaller companies - this is also why we don’t get the same kind of performance/capacity per volume out of “uncommon” cells like 10440, 14500, 16340, 18350, 26650 that we do from 18650/21700. The companies with the most money and R&D behind their construction/chemistry seem to only produce the highest volume cell sizes.
What’s nice is that we have seen improvement from brands like Vapcell and Shockli cells in some of those sizes. The recent 14500 comes to mind (Vapcell , Shockli ). But we don’t know who the manufacturer of that cell is.
Their 18350’s seem to be one of the best available on the market. They might not be consistent. But they’re probably suitable for most 18350 flashlights that don’t have a >10A current drain.
Reviews by HKJ and Battery Mooch might help in deciding whether to try out a particular cell.
Orbtronic makes no claim of ownership of the cell, they tell you the cell is Panasonic and they provide the protection circuit. How can vapecell take a Samsung battery, put their purple vapcell wrapper on it and call it a vapecell? Sounds illegal no? Can I do the same thing, just rewrap batteries and put my name on it?