Kroma on 18650s ?

OK, I've searched through the threads and saw some discussions about this, but never really seemed to find a definitive answer. I currently have a Leef body on its way for my U2, and apparently that body will fit the Kroma head. But does the single 18650 battery power the Kroma properly (given the complexity of the head) and safely?

It entirely depends on the Vf of the LED. If you are lucky and get an extremely low Vf, then it will probably run in regulation. Otherwise, you'll just underdrive the LED.

Yes. I have 2 Kroma's. Both work nicely with 17670, so 18650 should be fine.

Make sure you get good LiIon's with a nice button on top, or a magnetic spacer... I've tried my Kroma/s 2 times now with a 17670 and not gotten it to light up... today when I tried it (after reading this post and checking out the leef tube, which I like BTW, might need one myself) I pulled the head off and did some testing with a meter as the connection for the back end..

17670 definitely will light the kroma up, no problem, pulls just under 1A, however the cell I have, for some reason will not light up when assembled, I think it's because of the alignment and the fact the cell doesn't have much of a button top to it... the spare 18650 I have laying around is even worse yet.

So I'd highly recommend trying to find a cell with a good buton top to it, or picking up one of the magnetic spacers to help it out...


This is just what I've figured out on my own... I would like to run at least one of my Kroma's off rechargeable, but had been unsuccessful up until now, I'll probably get a spacer and new 17670 since the one I had is already in use in my E2W

Thanx folks. The cells I have coming should be AW button tops, so no magnet required (hopefully). I guess I'll throw the head on and see how it goes.

Will, you can also stretch the (+) on the head just a tiny little bit. Don't over-do it or you risk compressing the cell.

A quick update. Received the Leef body and button top AW 18650s today. Both work perfectly with the U2 head and tailcap. Cannot get even a flicker out of the Kroma / Leef body combination. Tried all three cells after reading past posts that stated some of the Kroma heads are finicky and would only light when using specific cells. I even tried the magnet spacers that came with the cells.

Guess I should name my Kroma Morris (After Morris the cat for those of you old enough to remember that advertising campaign). It just will not light off of a 18650 cell. Still VERY pleased with the U2 performance and that alone made it money well spent.

Re: Kroma on 18650s ? Success!

OK folks, something I did not know and just stumbled upon while surfing Lighthound's site......The Leef U2 body requires an additional washer for the stock tailcap to complete the electrical circuit. And yes, I now have it and it works great. This is probably old news for many of you, but I thought I'd throw it out there for any other relative newbies to the Leef body. The washer is only $1 and the Leef U2 bodies are still on sale.

Alan