Lux I, connected directed to 3 AA Nimh w/no resistor

Hello everyone, I'm new to flashlight modding here. Just curious, would it be detrimental to connect a Lux I Lumiled directly to 3 AA Nimh with absolutely no regulation and resistors?

I actually just finished concocting my little invention here and currently testing it out. It seems brighter than with a resistor (duh ) and so far it has lasted for 1 1/2 hour and still bright, probably at 75% brightness. I've got it sitting on an old A64 CPU copper heatsink so its nice and cool at the moment.

Any input would be appreciated.

Edit. Also, would anyone know where I can get specification information on Luxeon I and III. Basically, I just want to know how much minimum and maximum volts and amps they can handle.

You can go to the Lumileds website and download all the stats. As long as they've been out, people have been driving these with 3 batteries (AAA, AA, C, D). The only thing is a shorter life and decreasing output over it's life. Not really noticed though. The one big thing to make this work though is good heatsinking which it seems you have. Use either thermal paste or epoxy and as little as possible. Just enough to cover the bottom where there isn't metal to metal contact by filling the microscopic scratches.

http://candlepowerforums.com/vb/showthread.php?t=79520

Good reference of how much amperage is going through from 3 AA NIMH depending on the bin of the luxeon -

Thanks a lot for the info guys. So far for my little test, the runtime was about 7 hours to 50% on Nimh and was pretty bright even at 50%.

Sorry for the newb question here. Since I'm using 3 AA Nimh 2000 mah batteries without a resistor, how much ma is really going into the led? 2000 ma?

The easiest way to find out how much current is going to the LED is to measure it with a digital multimeter (DDM). There are inexpensive ($3-6) models available at Harbor Freight or Frys Electronics (Frys recently had one for free after the rebate).

We would need to know the bin of the LED to even begin to guess exactly how much current (mA) three NiMH cells can push through it. Sorry I couldn't be more help.

Just from personal experience I've had anywhere from 900mA to 1.5A depending on the total resistance of the electrical path. Threads, gunk, body material, switch contacts, springs and contacts, solder quality, grounding connection and quality, battery capacity and quality, etc. As long as the thermal path to the LED is good and transfers heat to the body quickly it should be fine at least for a few hundred hours.