Actually i already modified a Roche F6 single-18650 with warm white XM-L, a Q-lite 105 with reduced number of 7135 chips to increase the run times, and built a special removable diffuser that converts in into a functional lantern much better than diffusers does. On medium-mode with a 3000mah cell it runs for 12 hours non stop, and puts out roughly 200 lumens, brighter than most store bought “crap” led full size lanterns. ( can take photos if wished)
Excellent concept! Very interested to see how you execute this… seems like it would have potential to be a very popular group buy. I have no doubt that the vacuum of worthwhile LED lanterns will finally be facing elumination! Lol, Oops.
I am definitely in if the price is able to be kept or optioned on the economical side, or probably as soon as my budget will let me.
I had just recently broke down and started brainstorming ideas to mod a small, cheap, poorly executed 4x AA 5mm glare emitter/lantern to run on an 22650 or maybe 2 18650(s) adding a diffused output and efficient warm emitter and driver. I really like the downward firing emitter idea, sounds like the kind of thinking that has been absent from commercial LED lantern manufacturers all along. Sounds like you are off to a very promising start!
I have one more consideration, even though I’m sure I can trust that aspect with you: make the lantern very attractive looking (even though IMO it does not necessarily have to mimic an old-school kerosine lantern)
In my opinion this is much more important for a lantern than it is for a flashlight: a lantern, when camping, is often the center of the attention, and must add to the good vibes of being in the open. I see the cheap plastic angry-blue crap everywhere and that immediately makes me feel depressed, while my handsome old Feuerhand always makes me smile.