# XM-L T6 or Triple XP-G R5?



## Mattaus (Sep 11, 2011)

Hi all,

I'm looking to modify a small single 18650 flash light (cheap one off DX). Nothing special - just for sh*ts and giggles really. It comes with an XM-L T6 installed but having only recently got into the LED game and using nothing but XM-Ls for my experiements I feel they are getting a bit boring for me lol. I wan't to try something different but not if it severely compromises performance.

My questions is thus: one XM-L T6 driven at 2.8A or 3p R5's driven at 933mA each? The XM-L would use a reflector while I would use carlco optics for the XP-G.

The single XM-L should be brighter (though it'd be too close to call it) but which would be more efficient? I've read somewhere that the R5's are more efficient at lower current but that could be BS. Would 3 LED optics produce a nicer beam than a reflector? For some reason I think so.

I will keep reading and researching but I just thought I'd get people's opinions. Given the XM-Ls performance I would have thought triple LED builds would have died out but they seem to be as popular as ever...so I'm curious as to why.

Cheers,

- Matt


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## jasonck08 (Sep 11, 2011)

Minimum Emitter Lumen numbers (Give or take a couple lumens) according to Cree's Online Tool:

1x XML T6 2.8A = 874 Lumens

3x XPG R5 2.8A = 988 Lumens

I'm not sure about the beam patterns though, but overall the 3x XP-G's should definitely be brighter, but not by much.


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## Mattaus (Sep 11, 2011)

Oh nice. Thanks for the alerting me to the Cree tool. I didn't know it existed but now that I do it should come in handy!


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## vaska (Sep 12, 2011)

Though a set of 3xXPG is more effective than 1xXML, I choose XML for my headlamps just because of times wider selection of optics for it in 20-mm range.


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## Mattaus (Sep 12, 2011)

vaska said:


> Though a set of 3xXPG is more effective than 1xXML, I choose XML for my headlamps just because of times wider selection of optics for it in 20-mm range.



Good point, but for me I pretty much want the 3xXPG for a specific optic. The extra power is a bonus.


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## Toaster79 (Sep 12, 2011)

Cutter has some S2 binned XP-G's listed


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## LEDninja (Sep 12, 2011)

Toaster79 said:


> Cutter has some S2 binned XP-G's listed


 People with S2 torches complain they are too green. YMMV.


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## jasonck08 (Sep 12, 2011)

LEDninja said:


> People with S2 torches complain they are too green. YMMV.



With 4 bin choices, I'm sure people can find a decent bin.


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## Mattaus (Sep 12, 2011)

Hmm...so even more light hey? Might have to look into it.


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## Mattaus (Sep 13, 2011)

Actually maybe people can help me here in regards to Cutter MCPCB's. If I want a triple XP-G S2 on a 20mm PCB which "XPG on Metal Core PCB" option is it? I seem to recall seeing in another thread a guy was talking about the XPGMR8SER option and all his pics were of a triple R5 set up... 

Also I've just discovered that the Queensland distributor for Cutter is about 2mins from me. Awesome.

EDIT: I may have worked their naming convention out. Cutter-XPGMR8IAD means XPGs on an MR8 based PCB where each emitter is individually addressable ("IAD". "SER" is for series wired PCBs).The MR8 standard I believe is 20mm - but I am basing that totally on the fact that all the MR8 PCBs appear under the 20mm section of the cutter website.

Have I got it right or wrong wrong wrong?


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## Mattaus (Sep 14, 2011)

Anyone able to shed some light on my last question? I emailed Cutter but am yet to receive a response.


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## qwertyydude (Sep 15, 2011)

How about triple XM-L?


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## Mattaus (Sep 15, 2011)

I'm limited to driving the setup in parallel using a 2.8A driver. So the XMLs will only get approx. 930mA each. That'd being said I had not considered XMLs so I may go and see if that offers better performance than the Triple XPGs. Another option in my mind was driving triple XPG S2 setup with a 1.4A driver (460mA each). This would give me a little over 500 Lumens total.

Actually screw it; I need to think a bit more about I really care more about - absolute power or run time. I keep thinking 1000 Lumens is a 'good' goal and then I remember exactly how bright that is!


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## Mattaus (Sep 15, 2011)

So I've decided my goal is 500 Lumens. 

Seen as this is going to be used in a single 18650 'survival' light I figure running time is more important. Forcing a maximum output limit is in my mind better than giving the user the option to limit it - if they're anything like me they will want the flashlight to be as bright as it can go all the time :devil:

Using a 1400mA driver connected to 3 LEDs in parallel forces approximately 460mA through each LED. According to the Cree calculator the XPG S2 will give me a higher output (by 2 lumens per emitter lol) but the XML will give almost exactly the same output at a lower Vf - which means less consumed power and in turn less heat would be produced (3.78W versus 4.15W for 3 emitters).

Does that make sense? More importantly is this right?

EDIT: Of course this may all be for nothing - I can't seem to find 3-XML 20mm boards. The 20mm part is important. So I may have no choice but to go for the XPG-S2 option anyway. No skin off my back!


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## IMSabbel (Sep 15, 2011)

20mm is arefully small for 3 leds. Even if you could squeeze them together, it would be almost impossible to get an even halfway efficient optic (be it reflector or TIR) for 3 leds in this size constrains. That alone could very well eat up all your differences.

Also, you have to consider driver efficiency differences!


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## Mattaus (Sep 15, 2011)

OK maybe it looks like I'm trying to be technical and I am trying to keep heat down with light output as high as possible I am not going to worry_ too much_ about it.

I will be using shingingbeam drivers, so as efficient as they are is as good as it will get for me.

In regards to the optics I plan to use 20mm Carlco triple optics as they seem to be very popular.


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