How are you measuring current?. I guess you are putting one multimeter tip to the battery negative and the other to the flashlight body. Are you?
Take a look at the body ends. Probably there is to much paint/anodize.Try to sand body ends and see if that improves current. My guess it that your flashlight body is not doing good contact with the pill (driver).
the resistance from the end of the body, tube to the negative of the pill. Zero Ohms. I mesured the switch. Zero Ohms. The only conclusion I have is: I have got a faulty (or somehow different) XM-L. Even though, the light output I guessimate, is well around 800 to 900 lumens. Just now I tried with a blue protected Trustfire battery, that has 4,15 Volts and suddenly the protection kicked in on high mode. This is a sign for a high current draw, isn't it? The mistery persists.
Now charging two brand new flame trusties. Will see.
Maybe it is time to get a new multimeter:
I have this cheapass that works beyond belief well:
althrough i bought it locally for around 12€ discounted (:/) im still happy with.
Compared to a telecom guy fluke it is still decent. I did a set of current, voltage measuerements all DC and the results were quite ok if we assume the fluke is 100% correct.
With the stock probes i have no issues measuring current of 5A (a lab power supply). Your mileage may vary since 3USD for a multimater makes me want to cry. XD
One time when i was still working for an ISP i had the pleasure to carry an extremely epensive "multimeter" have to ask an ex coworker to led me that a wekend again. We used it primarely for locating faulty connections on telecom wires with the use of a special reflectometer. Have to try that one since it gets calibrated every 5 months for all measurement purposes.
I have got it from DX. It has quite thick leads and was working well so far.
http://www.dealextreme.com/details.dx/sku.32418
Well, I cannot be 100% sure the meter is correct, but it's the first time the indicated value is so far off the expected level. I would say, I still keep it, til I get my next XM-L light. 
Btw I tried with a new flame trusty at 4,20 V. Current reading was 1,7 amps and the protection didn't trigger.
What brand and model 18650 cell did you use for this test?
Did you try to measure current from the cell directy? o.O
I was refering to the fact, the blue Trustfire battery triggered the protection, when I used it in this C8. The cell I used first, was an unprotected one.
When the protection triggers, the current must well be above 2500 mA, for this to happen. With the flameTrustfire battery the protection didn't kick in. Conclusion: The readings with my DMM are suspected to be wrong.
Oh, thanks for the explanation. My XTAR and Hi-MAX ar able to pull 2,9A and 3.1A and the protection doesen't kick in yet. Have to check the specs if i find some.
What he said? (seems machine translated engrish, with a slight reference on plumbing?)
Utter gibberish! It sounds like something but it is really nonsense, there are text generators for this kind of thing. I think that it is testing BLFs spam filtering...
Either that or a very bad machine translator is being used. We will know soon enough.
How are you Emiax?
Finally got mine in yesterday, tried it out last night. My first in the "barn burner" category... and WOW. 
Is it normal that high and medium look so close in brightness indoors & outdoors? (protected trust flames) I may run a DMM on it later this week, if the high/med thing is abnormal.
Mine doesn't have a plastic piece between the reflector and star/led. It's just a thin white "cardboard" ring. After cleaning & lubing, it took me a while to get the reflector properly ~re-centered best as I could in 10 minutes of tapping and turning. Is there a place they can be bought?
This light out threw and out flooded my other stock (so far) lights by miles in a snowstorm R5, R2, and Q5. On high/med it's WAY too bright to use at close range with snow on the ground, lol.
Use the card made one as a stencil and make one form a plastic binder. Wouldn't pay (and wait 20days) for something that could be done in minutes with household junk. Can't be all that fun but it is gratifying to craft something by yourself.
Ah, so it's basically the same shape?
I'm lucky to have a friend with his own small machine shop, and over 40 years tool & die experience. :) I might be able to optimize the functionality by adding a few small bits that come up around the reflector slightly, not enough to transfer much heat into the reflector, but enough to center the reflector at the last second.
I'll have to see how much he likes bright things. ;)
Maybe a rubber washer in a local plumbing acessories shop could be just what youre looking for.
3A from a single 18650 ?! Are you sure this is correct ? I don`t think it`s normal ... These 1.6A of Oldienea sounds quite more realistic for me .
I suppose that for $30 the flashlight is direct driven ?
"3A from a single 18650 ?!"
mine is ~3.2A
"I suppose that for $30 the flashlight is direct driven ?"
sure
Hi everyone, I've been watching this thread since I saw it on kaidomain so I just had to register
I got my light today and measured with a fluke 87 I got 2,35A with a fresh cell which seems a bit low. I will put some more solder on the module and improve connection between module and casing tomorrow to see if this improves. Overall a powerful light, but the current confuse me. I used these cells:
http://www.dealextreme.com/details.dx/sku.5790
http://www.dealextreme.com/details.dx/sku.19624
compared to this light
http://www.dealextreme.com/details.dx/sku.42972
it is brighter but im still impressed by the light the XP-G emits at only 1,15A (full blast)
Glad to have you here, mbee! Sometimes one battery just can't deliver that much current (and even if it could, it wouldn't be able to do it for very long). I am impressed with the amount of light the XM-L puts out, but I still like my XP-G lights for walking around, just as I like them more compared to MC-E and P7 lights. The spill of an XM-L can be kind of blinding. If you need that much light, it is nice to have, but it's almost too much really. You turn the light down to a lower level, but you lose that much throw (at least for P60's; maybe this light focuses the beam better).
Welcome mbee. :)
I'm totally happy using this light outdoors on medium, although everything is covered with white stuff right now which makes it seem even more crazily bright. For indoor, low is a must... still surprised how bright this light is on low.
But yeah, my EDC is a new TrustFire R5-A3. The hotspot is twice the size of this C8, and that new R5 is basically pure white, all around better indoors. But if I think I'm going to be outdoors much, this C8 is definitely coming along for the ride.
By the way, I just re-adjusted the reflector on my C8 just now, and the spot just got quite a lot more focused, although the green ring didn't change in size, just the size and brightness of the center. I'll go try it in a little bit.
[edit] OH MY GOD that made such a huge difference. i think what might have happened before is somehow the ceramic square wasn't actually sliding into the hole in the cardboard alignment ring. my observation of the increased green ring brightness (and overall brightness) would confirm that since the green light comes off the extreme sides of the dome, not the center. outside i would guess that throw was more than double from that reflector adjusment, even though inside it didn't look like a big change. Now double blown away by this led & light. I can see the pictures on the walls of people's living rooms from 2 blocks away. Scary. lol [/edit]
I used these cells:
http://www.dealextreme.com/details.dx/sku.5790
Welcome!
Those Trustfire's can deliver above 4 amps (I have a handfull of them)