Low current XM-L Test

http://www.kaidomain.com/ProductDetails.aspx?ProductId=11218 Driver used ..

http://www.kaidomain.com/ProductDetails.aspx?ProductId=11399 Empty pill used

I dont know why so much negativity towards XM-L 's driven at lower current ?

So I thought I would build a low current XM-L drop in for my 2nd L2T .

The driver chosen was done so because its 1.4A , and because it can be modified to 3 mode [ More Later ]

The pill was chosen because I havent seen it before , and because it looked to me like it might be the perfect XM-L fit [ which it was ]

I cant say it throws a better beam than the OP reflectors [ very personal ] , but it does a good enough job .

Lets check on some performance figures :

High = 470L - 1.41A

Medium = 148L - 0.44A

Low = 24L - 0.07A

Now those figures are impressive to me , not only for output VS current but also the run time offered .

With a decent high capacity cell , High is good for 2+ hours [ longer due to diminishing Voltage current trend ]

Medium offers around 7 hours ,

And low some 40 hours +

I just cant help but like it , wont be dark for a few hours yet , but I can see liking this drop in very much .

I know some folks just want all the power they can get , even if the emitter suffers massive lag , but so far this one has little if any lag .

I only just completed it : So more after I play with it some in the dark .

The driver mod , you can see the 2 pins here that need to be shorted to each other , a bit of solder should do , and you have a 3 mode driver .

Sounds good to me! I don't understand 1,000 lumen lights anyway. Can one really tell the difference between 1,000 lumens and 500 lumens unless the two are compared side by side anyway? :)

Have fun!

I just ran it on high on my desk - bezel down - and it barely got warm after 5 minutes [ no heatsinking ]

Yeah , after 300L , especially in the back yard , it makes no real world difference , I can tell the difference in output , but it makes little difference to how well you see , if I had a bigger back yard ?

But I will test it tonight and see how it goes , I think it will be sweet .

Yesterday I've used very same driver to modify one of the cheapy zoomies from UltraOK with XM-L. It doesn't focus well (yet) and I have to do some work about heatsinking (I'm going to attach 1 euro cent under 16mm PCB), but it give decent amount of light at it's wide position. I can say much more than any zoomie I have. I have to compare it outside with others and drop-in described below.

Regarding 1.4A driver and P60 XM-L, I have one drop-in of that kind from DX and it does resonably good job. It looks like just a little less bright than ones driven at 2.8A. It can be perfect drop-in for 16350/18350 lights like this one.

I've noticed when comparing two headlamps (at night) where one is floody and one throws a bit more that the difference between 200 lumens and 100 lumens is barely noticeable with the floody light. With one that throws you can see that it can throw a bit more when going from 100 lumens to 200 lumens but that's about it.

With the flood lights I think of it like buying a bigger and bigger air conditioner for your house but leaving the back door open:) You can't cool the whole outdoors and with a light you can't illuminate the whole outdoors either:)

I guess it's fun to try sometimes:)

1,4A is pretty bright for an XM-L flashlight with only one 18650, and it won't overheat (if there is good thermal contact between the drop in and the flashlight).

I have this drop in http://www.dealextreme.com/p/cree-xml-t6-5-mode-6700k-450-lumen-smooth-aluminum-drop-in-module-with-textured-reflector-55026 and it is very good. But i did use some aluminium from a beercan to fill the gap between the drop in and the flashlight (the drop in fits very tight in the flashlight).

That drop in pulls 1,26A (high) 0,37A (mid) 0,03A (low) at 4,2V. But the new ones are reported to be direct drive on high. So if you order one now, it will be brighter, but it will heat up much faster too.

Its almost perfect - Its dark out , and I cant ask for better .

Each level - Low - Med - High , are just about perfect ...

Low mode is soooo sweet ... 24L for 0.07A ....

I need to buy another A20 and use one of these drivers [ Need ? ] , well .

I absolutely love an XM-L @ 1.4A. The efficiency is fantastic and its plenty of light for a P60 format. I think 1.75A might be ideal, but I prefer the lower low. I also like an XP-G @ 750mA for a emergency light.

I just ordered both. I have no willpower. :)

Got a L2m as a workhorse with 3-mode R2 dropin, that draws about 1,1A very roughly. Using 18350 to power it for less rattle, more runtime.

Problems:

-Too bluish to my taste

-Too small spot in many situations (work use, mostly 1m-12meters distance)

-Just a tad too little lumens, not bad but in dark big factoryhalls in nightshift just doesn´t cut the cheese

-Bad PWM...

old4570, this seems to solve about all these problems, thanks for input! OK, I will have to sacrifice some runtime... But mainly I use short bursts, 2min is about the longest I need. So, no heat issues but no sense to go for 2,8A or even more :|

Sounds ideal, to use less Ampers to get good runtime YET with good amount of lumens and efficiency.

I'm with Matt when it comes to not understanding why everyone downplays the XM-L at lower amps. It's brighter than an XP-G and runs lots more efficiently. It's like a big block Chevy engine lumbering along happily spitting gobs of torque to accelerate at a certain rate compared to a small 4cyl engine screaming at high RPM's to accelerate at the same rate. They both accelerate just as fast but the one does it without the stress and heat while the other is at 100% struggling to keep up.

The XP-G isn't that much smaller of an emitter compared to the XM-L either and neither of their hot spots are small compared to an XR-E. I have a Yezl A1 with an XP-G R5 that gets hot as balls on high within a minute. The same light with an XM-L would run lots cooler and be brighter.

Same with the folks who start proclaiming that you can't run an XM-L at 2.8+ in a small light because it'll either overheat or destroy the battery. They'd be right if it was a single-mode driver but not when it's a 3 or more mode driver. That's what low and medium are for! High is only for short runs on a small light and doesn't hurt a thing when used responsibly. On medium it will still equal or out perform your XP-G on high and run cooler and more efficiently for your delicate little battery PLUS when I need a little extra oomph for a few minutes I'll have it.

Ditto.

My overdriven XP-G driver fried. Found on the shelf an unused 1A driver (AK-47c). Drives R5 "only" at 1A but what a nice low and more runtime on 3xAAA (L2i) yet not that bad loss in lumens. And nothing about those heat issues with flickering like before...

BLF - getting things to work the ideal way :)

I ordered this XML dropin http://www.manafont.com/product_info.php/cree-t6-3mode-himidstrobe-memory-led-dropin-module-42v-max-p-5273 by mistake. My DMM is crap so I can’t measure amps. The output is 540 lumens on high. It still gets hot but takes noticeably longer to get there than my other XML dropins. I tried different batteries, it must just be driven lower, not DD. don’t know if they are all like that but that’s mine. I like it. 540 lumens is still a super bright light. The strobe sucks though. Slow, more of a fast beacon.

I had one of those drop in in a 504B I did the 3 mode mod I loved it used it for a while and ordered two more and put a XPG R4 3C in it. The two new ones showed up with different drivers, direct drive Ultrafire 5 mode drivers instead of AK47s I was so bummed out. I ordered 5 drivers from KD so I can make a couple more low amperage XMLs it is a great idea it just makes sense having a super nice low and 500 lumen high is plenty, great run time better heat control it works great for all the right reasons.

Thanks for that test, Old4570. It's a long time coming.

I've said all along that the XM-L did very well at low amperages, better in my experience than an XP-G. Those who were downplaying it, appeared to have no personal experience, and there was no shortage of them. I sometimes draw ire for speaking against "doctrine", even on here, which is supposedly a haven for contrarians and heyoka.

I've been trying to find the time to mod an XM-L to one of those cheapo "3 watt" 3 x AAA headlamps with no-name LED (I think the same as the recent dino freebie). I do have the emitter now. I anticipate it'll draw more than 3 watts, which would be nice (it drew 0.7 watts at 4.5 volts with alkaline AAA's).

Your 470 lumens came from about 5.5-6 watts. Split the difference, and that's about 81 lumens per watt, real-world Out The Front.

That said, I absolutely lurrrrve the XM-L when run hot :) .

I think the XM-L has a lot to offer ... And not just at maximum possible output .

My Trustfire F20 with AA is a good example , the XM-L emitter swap makes it ever so sweet .

My little A20's are fantastic with the XM-L - I will use this driver and build one more ..

And I will build one more Low current P60 drop in [ like this one ] using a XM-L emitter [ 2 U2's left ] , It is for the lack of better words , a very sensible drop in .

Great! Got the 1,4A driver today!

Soldered it in place, used my L2m as a host and.... this no longer feels like a beater after R2 got replaced by XM-L :|

Very nice amount of light, a bit under 1,4A of current.

I left it on the table for a good while. It gets all warm but can be taken to hand with ease. Not too hot!

Efficient!! No visible PWM!!11eleven!

Thanks old for sharing this, really made my day :)

My battery is at 3.9? and is still in regulation , with the glue set , output is a little higher ..

Im currently trying to see how low I can go and have the light @ full output , but I seriously like this combination .

Back at school , so time is a bit at a premium again ..

I built a 1.75 amp XML drop in last week and I am very pleased with it. You can run it continuously and not have to worry about it overheating, and it puts out a ton of light for this format. I used a single mode 1.4 amp 7135 driver, and added another 7135. Pulls 1.8 amps at the tail, and has great runtime. The XPG is a great little led and will throw better than the XML if that is what you want, but the output of the XML is great and it will still throw pretty well because of the massive output.

I've got one running at 1.4A in a Yezl Z1X, one at 700mA in a AKOray 106, and one in a Nitecore D10 @ whatever it runs, probably 1A or less. The beam profile just suits me, even in small reflectors. I almost never have a need to light up anything beyond 100ft, but I have an XML modded C88 (8x7135) just in case. :) XR/XP lights are becoming rare around my house.

Just built a second one - and Im very happy with it ...

Its comforting to know you can run high for extended periods , and heat [ and related issues ] are not going to be a concern , and the light will maintain regulation ..

An update on that regulation ..

3.76v = 480+

3.68v = 473

3.53v = 433

Wow , so regulation is maintained to around the 3.7v [ battery voltage ] mark , and after that is slowly begins to diminish as the battery begins to fade .

+ This driver has low battery warning @ 3v , it begins to flash ...