3mm LED in AAA M-glite

I just received my order from LSDiodes for a few 3 and 5mm LEDs. I took a 3mm white LED, cut the leads down to match the bulb and plugged it into a M-glite 2AAA. The 3mm led fit the reflector fine and it turns on and off as it should. The output with alkalines is less than an Arc AAA standard white but usable as an emergency type light.
1. Is direct driving the LED pulling too much current?
2. Could I put a resistor in the tailcap to drop it down?

I am going to try a similar mod with a 3mm amber LED in a Solitaire. If it doesn't burn up I may make a few to give away as gifts. Has anyone tried this with amber or red LEDs?

I have a 5mm red led in my MM (aa), works great and doesn't ruin your nightvision (thats why i use it).
I had to enlarge the hole in the reflector though.
I'm not sure with how much you shorten the life of the red led on 2xaa.

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PJ said:
I just received my order from LSDiodes for a few 3 and 5mm LEDs. I took a 3mm white LED, cut the leads down to match the bulb and plugged it into a M-glite 2AAA. The 3mm led fit the reflector fine and it turns on and off as it should. The output with alkalines is less than an Arc AAA standard white but usable as an emergency type light.
1. Is direct driving the LED pulling too much current?
2. Could I put a resistor in the tailcap to drop it down?

I am going to try a similar mod with a 3mm amber LED in a Solitaire. If it doesn't burn up I may make a few to give away as gifts. Has anyone tried this with amber or red LEDs?

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PJ, could tell me what spec bulb's you got? i would like to try that. VDG

I would take a meter and measure the current used on the leds if you are concerned. Typically if you are below the Vf (forward voltage) of the led you are underdriving it and the current would be less than nominal going into it. I am not sure about the amber LED but my guess is you may be close enough on the voltage to not fry it as I have seen orange LEDs running off of 1 2032 with no problems. I suspect you could overdrive it but an ammeter inline will tell for sure.

If you try the new energizer lithium AAA batteries you will be suprised. Most of the 3 and 5 mm white leds want more than 3.2 to 3.5 volts. The energizer lithium AAA is slightly higher voltage than an alkaline. A pair will give you about 3.4 volts, just about what your led wants.

voodoogreg, I think it is 5,000 mcd max.listed under 3mm LEDs on lsdiode website. This should be a direct link to the info page for these.

http://www.lsdiodes.com/3mm/3mmwhite.htm

I am going to try a 5mm 12,000 mcd next in a 2AA light.

I may have to scrounge a new meter. My Fluke model 70 only has voltage and resistance.

lsdiodes seems like a pretty good place to buy from. I bought 10 various LEDs and they gave me 2 5mm blue ones free.

You seem to be under driving your LEDs. As Gadget Lover mentioned, use Lithium AAs in your Mini Mag you will get better results. Some CPF people have used White 3mm LEDs in Solitares by using the 12 volt garage door remote batteries with a dropping resistor or even direct drive. The other method is to use a boost circuit. This link will take you to one that I came across on this forum.
http://www.emanator.demon.co.uk/bigclive/joule.htm

I seen a version of this crammed into a Solitare. With just one 1.5 volt cell and no boost circuit you do not have enough voltage to even run a amber LED.

The 3mm in the 2AAA Mag ran for about 60 hours with little noticeable change in output, probably because it is rather dim to begin with. Output is definitely less than an Arc AAA.

I modified a 2AA Mag to fit a 5mm by drilling the reflector. I put a 12,000 mcd white in it and it worked pretty good. I then put a 6,000 mcd white in and the output is about the same as a CMG Infinity white (non-Ultra). It did not seem to be much less than the 12,000. I put a small washer over the LED to stop it from binding in the reflector and it works fine.

Nov.26
I picked up a Craftsman DMM on sale. Hooking it up to the 2AA Mag with a 5mm 12,000 mcd shows it running at 26 milliamps. The spec sheet says to run it at 25 so I guess it should be safe. The 6,000 mcd white was pulling 13 milliamps in the 2AA. I can tell the 12,000 is brighter but it doesn't look to be a whole lot brighter. Looks like the 6,000 may be the way to go.