I use the Windyfire for all my 14500 Li-Ion needs. I don’t really use 16340 cells. But I do have some of the Lumintop branded ones. Not sure who makes them but they do just fine on my lights. They are protected and the few lights I do have that use them don’t have low voltage protection so it keeps me from damaging a cell. The Windyfire’s can be had from Mountain for $2.99 a piece and a 4 pack of Lumintop 16340 can be had on Amazon for $10.