I don't bother with 18650's. My LED flashlights that can use 18650's came with an adapter that takes 3xAAA, and I just use no-name disposable alkalines that last a good long while before having to be replaced. It's likely not as environmentally friendly as rechargeables, but it's convenient and cheap. I think a 40 pack of AAA's costs somewhere around $20 at Costco, something like that.

I've always thought it was too much of a crap-shoot buying specialized rechargeable that aren't readily available due to the plethora of badly made imports and knock-offs.

Maybe input from a thread like this will inspire me to look into it again one day, but for now, the 3xAAA's just work for me without issue.

Cheers
TRJB