R/O Screamer help

Ok, here's my plan. I want to build a red/orange lux III screamer and get at those rated 190 lumens of eye-frying power. Now, here's what I think I think - I need good heatsinking to accomodate the 1.4A current required for this output. My host of choice is the Emilion Smartfire 3AAA direct drive clone light. Swapping the clone for the R/O lux III, I think the heatsinking would be adequate. For power, I'd be using 3 AAA nimh cells, which should, in theory, be able to supply this kind of current which should be a bit under 2C. I could use a li-ion 18500 cell as a swap out for the 3AAAs. So the questions are:

Which battery source would be better? I realize that the 18500 would provide much more capacity than the 3AAAs (1500ma vs 900-1000ma), but would I be overdriving the luxeon to dangerous levels? The R/O bin is G2HH. What voltage is required to push the correct current through this baby? I know that the H vf is 3.03-3.27V, but that's at 750ma, isn't it? I think the li-ion would hold a higher voltage than the 3AAAs for longer, but it would be relatively close, I believe. And the li-ion would have no problem supplying whatever current the luxeon would be willing to draw.

Opinions?

Let me save you some trouble. I did a simalar 3xaaa light with NiMH. My cells were lacrosse, 750mah or so. The voltage sagged on them, so I had to go to a lower Vf luxeon. I used a G2G. H Vf didnt work too good. Now it pulls just 1 amp on HOTC cells.

Other brands might be able to deliver more current. I belvie there was a shoot out or post recently talking about one brand of AAA nimh that beat out current deliver of some AA's!

With what you already have, go with the Li-ion. Test it first and see if it over drives it, becarefull though as close to 2amps the bond wires fuse open! You will probably need a resistor, but maybe not...

/ubbthreads/images/graemlins/caution.gif /ubbthreads/images/graemlins/caution.gif Also, remember that both the slug and the star's metal are connected to postive lead. If you don't isolate this from the HS/body of the light which is tied to negative, you will ruin your luxeon, as the positive bond wire will dead short and melt open!! /ubbthreads/images/graemlins/caution.gif /ubbthreads/images/graemlins/caution.gif

Hope this helps! /ubbthreads/images/graemlins/wink2.gif

If you have NiMH go a head and try them first, your's may be able to supply the current. If not, then just go with your Li-ion. oh and to isoltate the emitter/star use AA epoxy and test the resisttance after it sets up to be sure.