DD 1 watt Luxeon with 18650?

I was playing with my Dorcy Metal Gear and I'm DDing them with the 3 AAAs but I was going to switch over to 18650s and wanted to know if I'll kill the Luxeon driving them like that? All my Metal Gears are R bins not sure if that matters.. Also, where is my best spot to pick up batteries? I don't wanna buy from AW so please don't say there.. There has got to be less costly places to buy from.. I got the DSD charger for $9 shipped so I know there are wholesale places on the net...

THANKS A MILLION!!

When you say you are running them DD on 3xAAA cells, you do mean that you've removed and bypassed the resistor, right? I think an 18650 (or 18490) with the resistor would be just fine and would probably give much greater runtime with only a slight reduction in brightness. That's how I would personally go... I figure, stay with the Lux I for good brightness and great runtime and if you want it as bright as possible, bypass the resistor and go with a Lux III.

Other than buying modded lights that came with LiON cells, I've bought every one of my LiONs (about 15 maybe) from AW. He's always done me right and sometimes the shipping is scary fast.

i modded 3 dorcys, that used AAA, to li-ion 18500, and they work great.
but it was a LOT of changes.
the heat sync was about useless, and inefficient, and didnt send the heat OUT well.
the LED was only a 1W , after having to fix the heat sync the led itself was no big deal to change.
the curcuit they HAD in the ones i modded, would have had a fair ammount of resistance.
i replaced thier curcuit stuff (who needs strobe) with a 2way switch.
about 4ohm resister ran it at about 1W, the other side is DD, with wires that have a bit of resistance, and it runs HOT, like up to 2A. and i think i used a k bin, or j bin, i forget.

also gotta remember that the Vf goes DOWN over time, so if you get a led that can handle 3.9V then 3.7 after time, you probably would want to add in a microbe of resistance, or depend on the resistance throughout the unit.

easy way would be to get done what you want to do, have the battery fully charged, and check the total current IN the light, if its to high add a bit.

if it has one of them tiny curcuits, that might just blow faster than an overdriven led, protected li-ions have a bit of resistance too.
the idea is, all the math and science in the world will not determine your exact current , because of all the parts and pieces, a small wire alone, can put in a lot of resistance at low voltages and high currents, ,the Voltage that the led is now, the cuircuits can add in drop from silicoln and resistance.

the thing to do, is DO IT then test it (for a second) before your finished (with full batt), and alter it if nessisary. then remember that there is a vf change over burn time. (the led will become more sensitive, and current will go up a bit)

the reflector is great.

so if they got a resister IN there now, and the curcuit can handle FULL 3 w, then you might get away with JUST a change to the resister in there.

A good set of hot off the charger ni-mhy batteries can put out a fair ammount of juice TOO, similar to the 1 li-ion. so if it will hang with them, chances are it will hang with it, the tri holders do add in resistance.

but if it was alkaline ONLY designed, then you must add resistance.
by the way george has a new PWM thing that might just Barely squeese into that hole, and provide awesome levels. it would be a lot of fudging to get it in, but its a thought.

There's not really a 'circuit' in the Metal Gear, just a PCB with a 1 or 1.2 Ohm resistor.

To the original poster... what exactly are you going for? Do you want more brightness, or just increased runtime? I think the way to go for a nice overall light would be to cut down the plastic housing, get the resistor in the smaller housing (maybe using 3rd Shift's post as a guideline) and run it on the 18650. That should give very nice runtime and should be plenty bright for actual use.

Much like the V2.0 vs the V2.5 Fenix, gaining a little bit of brightness often costs a LOT of runtime. If you want a bit more brightness and still good runtime, I might suggest popping a Lux III star in there and leaving the resistor in place. Remember, an under-driven Lux III is more effecient than a Lux I driven at spec and certainly moreso than a Lux I over-driven.

Heat isn't really a bit issue with the Metal Gear. It has a simple metal coin type heatsink that is better than the heatsinking (if you can call it that) in the Element but again, if you leave the resistor in place, I don't think a Lux I or Lux III is going to get too warm.

Not really sure what I'm going for... I'm just sorta playing I guess... I took the three metal gears I had apart, contact with the "heatsink" was poor so I added thermal paste, remove the resistor and that's all.. I don't know where to get 3w luxeons at a good price, I see them in the ebay light cheaper then the stars alone..

So my goal here is I guess to have a light that's more bright then run time but mostly I just wanna have a valid reason to buy junk I don't need and play with it. I was thinking it would be fun to cut down and put one 123 in...

Is there anything else I can do or add to make these "better"?

Well, I've never tried to get the reflector out, but in my opinion, it could use a smoother beam. The beam of the Element has a larger hotspot and a much smoother transition from hotspot to the spillbeam however, the Element has less throw.

I've bought all of my brand new Lux IIIs from Photon Fanatic on this forum. He's great to deal with... never had a problem and I can't recommend him highly enough.

In addition to trying some white Lux IIIs, you might try popping a red/orange Lux III in there. I have one in an Element that I run on AAA NiMH cells and one that I just put in a Q1 yesterday that I run on an R123 cell. To say they are bright is an understatement... much brighter than any white Lux I've ever seen.