Recommendations for brightest SINGLE led

Considering taking three LED design down to one for flashlight system. Any recommendations would be appreciated. I am currently looking at the Nichia NSPW500CS with the following specs: 18,00mcd, 3.6V, 20mA ... Anyone with input on this LED or others would be greatly appreciated.



As always, thanks in advance!

Are you looking at something like a 5mm led? Or just any led? If it's any led, I'd say a 5 watt luxeon to be about as bright as they are currently made.

Like what I_T said above. Also try looking into The Sandwich Shoppe. I think they will also build to your spec if possible. Hope you find what you're looking for and Enjoy!

http://theledguy.chainreactionweb.com/index.php

Nichia CS seems to be the brightest single die 5mm led, but max lumens isn't what 5mm leds are about. Go for a Luxeon, maybe even a 5 watt.

Among the 5mm LEDs, I think the CS is capable of being the brightest if sent 80+ ma of current but at 20ma, I really think that the 35k LEDs are a bit brighter and I think the Peak Snow 29 LEDs are just as bright or at least right in there.

The big draw with the Nichia CSs is that they can be pushed quite hard and still seem to hold up well.

Then we got the SMJLED in the background.

Thanks for all your replies.

Yes, I was looking at the 5mm. I have also looked at the Luxeon, but I am not too familiar with LEDs or the Luxeon either. It simply looked larger and more expensive, which is one of the reasons I steered away from it towards something like the Nichia. Any other input is very welcome.


Also:
Several of you mentioned about pushing the 5mm harder for brighter light. What are the disadvantages of this? I can assume shorter battery life and failure of the LED, or am I even close?

Thanks ..

You're right on concerning pushing the 5mm LED harder... same applies to Luxeons as well.

Many of the 5mm LEDs are 'rated' at 20ma, that is 20 milliamps. Some of them such as KevinL's 35k LEDs reach their almost peak brightness around 50ma so they are already doning a great job at 20ma. Some such as the Nichia CS can really be pushed hard. I have three lights running Nichia CSs direct on a single 3.7-4.2V LiON cell and they pull about 170-180ma initially and they have held up just fine. I have over 100 hours on one of them though it does have a switch so that will introduce some resistance but in actual 'real world' and not the CPF world use, 100 to 500 hours of use is an awful long time and would likely serve most non obsessive compulsive adults nearly a lifetime.

The MJLEDs and SMJLEDs are spec'ed at 100ma so you would expect them to last 'about' 1/5th as long on a set of cells as an LED that ran at 20ma. Of course, you'd have to look at the actual current chart as the voltage drops.

Just so you have a ballpark idea, you could expect the MJLED to run at about 30-40 hours of good brightness on a pair of AA lithium cells. I you could build a light with an LED with a Vf of exactly 3.6V that ran at exactly 20ma with a regulator that was 100% effecient, with alkaline AA cells, you would expect nearly 390 hours of runtime though this isn't likely to be found in the real world. Best we can actually do off the top of my head is something like the Princeton Tec Impact which gives 'merely' 120-150 hours off of 4 AA cells.

Problem with most of the existing lights that run a single LED at very low current have those freaky moonlight type beam patterns that most CPFers don't like. You could get one of the 5mm LEDs in a PR base intended for use with 4 cells and put it in the Tec 40 and would get a very useful light with outrageous runtime.

Thanks cratz2...

In regard to the Nichia CS that you run direct with your lithium cell at 3.7-4.2 .... If I'm looking at multiple coin cells (the 2032 or 2016 3V specifically) they would need to be run with a resistor, correct? Would you recommend any higher voltage than the 4.7?



The Nichia CS seems to run brightest around 4-4.5 V (according to Nichia specs) Would it be a general recommendation to try and hit this mark with a combination of batteries and resistors?



Again, a big THANKS for your help.

Chimo did some great head to head 5mm led testing a while back and produced some very informative graphs.

Check out this graph.

My KeyMate runs a 5mm off 4x button cells with a total V = 6V. I believe people have swapped the LED of KeyMates out to Nichia CSs and have had no probs running off the 6V. I plan to swap the LED on my KeyMate also to a CS.

Yeah, the button and coin cells have so much more internal resistance (I assume, or maybe just an inability to deliver much current) that the standard practice is to run white, blue and green LEDs off 6V.

The current Photon super duper light (Max Freedom, I think it's called) runs a Nichia CS on 2 3V cells. And KevinL offers his coin cell lights with the option of upgrading to one of his 35k LEDs and those run on 2 3V cells as well.

Thanks for the info cratz2! I was thinking about only running 3-cells (4.5V) as I've heard some people had done that and was going to look for a spacer, but if the LED likes 6V better, I'll keep all 4.