Running a Luxeon Star off of 3 nimh AAA's....

JollyRoger

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Running a Luxeon Star off of 3 nimh AAA\'s....

What do you guys think? If I use 3 nimh AAA's to power a luxeon star (heat sinked a bit, not too much though), do you think this is too much? 3 nimh AAA's will give around 3.6 V, but I'm wondering how much this voltage sags under load. Effective 3.4V?? Also, the discharge curve of nimh is favorable, so light output should be fairly constant and bright for (how long do you guys think? 3 hours?)

I'm trying not to use a resistor in my setup, as space is limited. Also, I say heatsinked a bit b/c I'm using a plastic housing....

Let me know what you guys think...
 

Mike

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Oct 26, 2000
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Re: Running a Luxeon Star off of 3 nimh AAA\'s....

My bet is you'll need a resistor. Atleast try it with a resistor first so you don't have a melt down.
 

vcal

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Re: Running a Luxeon Star off of 3 nimh AAA\'s....

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by roger:
What do you guys think? If I use 3 nimh AAA's to power a luxeon star (heat sinked a bit, not too much though), do you think this is too much? 3 nimh AAA's will give around 3.6 V, but I'm wondering how much this voltage sags under load. Effective 3.4V?? Also, the discharge curve of nimh is favorable, so light output should be fairly constant and bright for (how long do you guys think? 3 hours?)
I'm trying not to use a resistor in my setup, as space is limited. Also, I say heatsinked a bit b/c I'm using a plastic housing....
Let me know what you guys think...
<HR></BLOCKQUOTE>

My own experience:
I'm using 3 x 2/3 AAA NimHs in one barrel of my (modded) 4AAA DB with the white Luxeon Star LED, and I find that the 3.6-3-7v is pushing it a bit, but in short use (less than 4-5 min.) it's greatly bright (similar to Lightwave 4000-only much better color) and seems OK.
After that 4-5min., the head of this aluminum flashlight feels very slightly warm (not hot)

HOWEVER, it's drawing over 700mA used in that mode, so the little cells that I use only last 20min. or so. By COMPARISON, ran on 2.9v+ (2AAAs) currrent draw is only 80mA. So-the voltage will Not sag, but the mA current will dramatically rise.
shocked.gif

-Again, as Doug P. sez:-it depends on your individual LS element.
 

JollyRoger

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Re: Running a Luxeon Star off of 3 nimh AAA\'s....

Hmmm...true...

thanks guys. I guess I'll check the current using these 3 AAA nimh's...
 

snakebite

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Mar 17, 2001
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Re: Running a Luxeon Star off of 3 nimh AAA\'s....

i built a light using an ls.
took a cheap 6v lantern and 3 5ah d nicads current limited with a 1.2 ohm 2w resistor.
max about 450ma just off charge.
about 370 till shortly before the first cell dies.cooling the ls with a bx cooler attached with j.b. weld.a bx cooler is the green heatsink on newer motherboards chipset.
easy to salvage from a junk board.
works well and a neigbor kid wondered where i got the hid light.
he did not beleve it was a single led till i showed him close up.
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Quickbeam

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Jun 19, 2001
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FlashlightReviews.com
Re: Running a Luxeon Star off of 3 nimh AAA\'s....

It really depends on the LS you get. They're all different. Check it with a mulitmeter to see how much mA it draws at that voltage - 350 is the high end for the LS and it'll get really hot.

or even easier: just hook it up and keep your finger on the bottom of the LS board. If it gets pretty hot in the first minute or two, you may need to resistor it down.

I had to drive my LS in a confined space at 2.9 volts (regulated) to prevent it from overheating the regulation circuitry, but I've driven the LS at 3.0 volts directly off the batteries with no problem, but it gets pretty warm. Again, each LS is different, so yours may stay pretty cool (or it may get really hot!).
 

JollyRoger

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Aug 21, 2001
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Berkeley, CA
Re: Running a Luxeon Star off of 3 nimh AAA\'s....

I'm thinking of modding the nightbuster clipper with a luxeon (w/ optics)...and simply running it off of 3AAA nimh. Either that or adding three or so more leds to the light as it is...
 

snakebite

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Mar 17, 2001
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dayton oh
Re: Running a Luxeon Star off of 3 nimh AAA\'s....

not sure who the question what are you modding was to.
the ls mod i described is a eveready 6v cheapie lantern with no model number.
it is the one seen at many places for $5.00
including battery.the replacement battery can cost that much itself so i did not feel guilty chopping off the bulb retainer to make way for the ls.
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