are you using one or two 18650s? i just tried with two, and its doing flashes. or itll stay on moonlight mode.
but its also because my adapter tube is not perfect so the cells are still moving around or not connecting properly.
I think two is too much voltage for that driver. You can use a dummy cell or do a tricky end to end parallel configuration. There's a thread for that somewhere here. I'll link if I find it again.
only one 18650 will power this the same or even brighter than the 3xC cells? that would be great. soooo much lighter.
how do i get or make a dummy cell?
nm, found out how to make one here