Help with luxeon leds.

I have a headlight powered by 3 AAA batteries for a Luxeon I led. I want to put in a 3 watt luxeon if the 3 AAA batteries will work good in it. Is that enough voltage for a 3 watt luxeon? Or should I just buy some better colored 1 watt luxeon instead of this ugly yellow-green one I have in their now?

You can think of the Lux III as a premium Lux I. While this can be more complex purchase, a simple drop in is easily possible.

If you are trying to ensure that you obtain the "best possible results", then you will need to read the Lumileds data sheets on binning for color. The sandwich shoppe sells Lux IIIs, as does Lumileds distributor, future, but shipping from Future is a little steep for 1 LED.

you have some options.. like Harry said.. the 3 will likely give you 'nicer' light not necessarily MORE light.. most inexpensive AAAx3 lights use a direct-drive scenario and if they run lux1 they are usually seriously over-driving them.. putting the lux3 which i've tried made for a very similar amount of light but i had control over the color and also eliminated the over drive... you can 'go nuts' and put in drivers, etc.. My personal choice in the scenario you present would be to put in 3x AAA LiON cells in parallel and use an LDO driver.. see http://ldo.rouse.com

-awr

The headlamp I'm talking about is a Brinkmann 1 watt that you could buy from Wal-Mart for $20 or so. I put in a 3 watt from my Cabela's 6 watt *2 3 watt* flashlight, but hadn't ever really paid attention to how ugly that color is that it gives. So now I want a nice probably white but maybe cyan color. In case you don't know, I don't know very much about the different bin leds or anything, I'm just barely getting brave enough to attempt to modify lights and hopefully not break them.

If you want "a nice, bright, very white" color, then looks for a TWOK or TWOJ Luxeon III LED. They are farily common now. Look in the BST (buy sell trade) section.

Make sure you know if you need a "star" (with the hexagonal base) or emitter (just the LED and its surrounding black package)