If the forward voltage of XM-L2 is going higher and Cree is focusing on higher voltage solutions in future our standard flashlights are going to grind to a halt in the future. Perhaps we need to think ahead and start work on a 6V boost driver for single 18650 lights?
High efficiency should be a priority in my opinion, from a lot of reading i am left with the impression that boost drivers are typically low efficiency, not because of the mantra that they are inherently inefficient but because low efficiency drivers are cheaper to design and manufacture.
I don’t know about boost but it might be a good idea to keep up the good work on 2-cell buck drivers. I think it’s even harder to get a high power boost circuit into a small driver package than a high power buck driver and we’re further along with the buck drivers.
I’ve made some very good progress on my buck project recently (have a driver that’s running both 3 and 6v emitters stable up to 7.75A), I think that’s definitely the most promising short term solution (not only mine, plenty of other good buck projects happening too).
Here’s another option- look to Luminus
vF looks pretty impressive even up to max spec’d, need to see what one can really do. I’ll have one in a light here very shortly.
