Every three-XML version of this light I am aware of (regardless of what name is etched on the side) has a spring suspended drop-in pill with no thermal conduction path to the outside of the light. The LEDs in a spring floating design will not be able to sustain high currents for very long without thermal dimming or over-heating the LED die surface.
The HD2010 in this thread has a screw-in pill that conducts heat away from the LED efficiently, through the pill and into the host body.
Thanks Kramer and Rusty Joe for the clarification. As you see, I really had it wrong and glad I posted the question. It's the single LED version that I'm looking for and is the one I want to get. Thanks again!
You mean like this?
Sort-of, although that light does look like its pill makes contact with the body. Or at least the owner copper wrapped it suffiiently enough to touch the bezel area and transfer heat away. The light Richie is asking about is the 3-XML version shown below which has no thermal path. Its just a spring "floating" drop in, suspended in a pocket of air inside the bezel. Same host design on the outside but completely different thermal design.
http://www.easylightbuy.com/szobm-zy1600-3x-cree-xml-t6-5-modes-led-flashlight-torch_p876.html
Heres some pics of the same (poorly designed) light under another brand, post #44 where the lights owner talks about its poor thermal path.
https://budgetlightforum.com/t/-/2821#comment-112576
Conversely, a really good thermal design 3-XML is the Trustfire TR-3T6. Its pill/reflector base threads into the bezel to conduct heat away. A design like this will be able to run the LEDs at a much higher current, with less thermal dimming or risk of over-heating the die surface.
Mine is great except it has a connection problem when using the 18650. The spacer tube slides around in there, and ever so often, it will lose connection. This happens when I screw down the tailcap fully, not when I screw it down partially (remotely on there).
I guess I will have to get a 26650 battery, no? Would putting a toilet paper ring around the edges stiffen things up so that this doesn't happen, or would I need the 26650? The idea of more capacity to a battery and using the same 18650 charger sounds like a plan.
That pic is from my Uniquefire 3900 3XM-L. The only place the drop-in makes contact is the spring at the bottom and where the reflector base screws into a stainless bezel, which in turn screws into the head. You can see thermal paste on the heads. I tightly wrapped the pill with foldEd aluminum foil, then covered that with multiple rounds of copper 40 g strips until it finally made contact with the head.
Seems to have worked. Light body gets pretty warm after five minutes, downright hot after 15.
Hmm.. Does it do this with all your 18650 cells?... or is it with some but not others? The spacer tube is just a plastic tube, I dont see how that could affect electrical contact.
Are you using protected cells? I have had some bad protection circuits that developed intermittent contacts when the springs would compress the 18650.
take off the tailcap and use a paper clip or piece of wire and touch -B to the battery tube. If it turns on/off consistently then you havea good driver board.
I would first clean out all the threads and check all the screw-together parts of the light and make sure its all snug and there are no loose parts in there. The driver board is held in place with a small retainer ring, tighten that. Also clean out the tailcap threads and tighten the switch retainer ring.
Did you see my post above? with the clear insulator disk? I dont know if this will help your light or not, but it might be worth a try. Usually strange things happen when the +/- solder pads on the LED slug short against the back side of the reflector.
I can't think of anything else.
I am going to have to contact Tmart about this now. The tailcap switch problem has not been fixed. I put the battery in, and even after using a paperclip to secure the 18650 inside the tube, it still only sometimes turns on, but usually goes off unless the tailcap is screwed down really loosely, like just before coming off loosely. Nothing I have done has helped.
check the retaining ring that holds the driver into place. It could be that the battery is pushing the driver up and away from its ground connection. You could try tightening that ring. If you can solder at all, you can try removing the ring and adding a thin smear of solder to the driver's ground ring to make it a bit thicker and then secure the retaining ring into place again.
Didn't someone post beamshots of this light? I swear I remember a post from someone in the UK (a newer member) who posted beamshots and now I can't find that thread. In fact, I can't find beamshots of this posted anywhere. (I know there are beamshots of the Fandyfire HD2010.)
-Garry
Ok, found out I was confusing beamshots from the Cyclone C88 thread. But doesn't someone have beamshots of this Ultrafire HD2010? Or can someone who owns it at least tell me beamshots look identical to the FandyFire HD2010 found here.
Thanks,
Garry
I can’t say 100% for sure but given that they are the same identical lights except for branding I would bet my money (and I’m not a gambling man) on “yes” they should have identical beam shots.
I was re-reading some of Night Breaker's thread and he said the tailcap reading on high on the Fandyfire was only 2.3A. Perhaps it's just his test leads though. Still, the beam profile should be similar regardless of the drive current. I was hoping for it to have a bit more flood, but I guess that's the trade-off for having more throw.
I'm still drawn to this light! It's like a force I can't resist!
-Garry
You and me both, brother!! I’m just biding my time until I have the spare cash to pounce. Stupid DD and their sale on the iTP EOS A2 in stainless for just $19 was too much for me to resist this morning and has set me back on the HD2010! 
I know what you mean! I just shelled out a bunch of money on supplies for my upcoming cycling trip the majority of which was on a new leather seat that Between Rides convinced me on. I'm sure I'll appreciate the seat, but I wish I could have used that money on lights! I did order a UF-H3 I've been waiting to order for quite some time. I'm a little worried whether or not the china ordered supplies will arrive in time for my trip! (Trip starts June 3rd.)
-Garry
I will try and post some beam shots tonight. I am not sure if my camera is good enough. Furthermore I dont have any other XML light to compare it with. The only lights I have that throw this far are HID spotlights... which will blow it out of the water for lux. The only other lights I have that emit over 350 Lumens are MCE and P7 multi-die flood designs.. so thats also an apples/oranges comparison.
Regardless I will try and get some shots tonight.
Thanks kramer!
-Garry
Hi Garry... I just re-read that Fandyfire HD2010 beamshot thread and the owner reported its reflector is 52x38mm. I just measured my ultrafire HD2010 reflector and got the same exact numbers, so they appear to be the same exact light. Although my tailcap currents vary greatly (3.75A - 5.45A) depending on the cell used and the measurement methods.
When I measured the reflector on my UltraFire HD2010, it was 58mm outer diameter, 52mm inner diameter. While that makes it only ~4 or 5 mm wider than traditional 52-53mm outer diameter WF500/TR1200 reflectors (which are 47-48mm inner diameter) it is a drastic improvement in throw over those other reflectors. The spot it produces even edges out the 52x40mm Mag LED reflector. If you want a non-aspheric XML that throws, this is the ONE to get.
I wonder how this light compares for throw and light output with the Skyray STL-V2. Thought about an HD2010 but bought the Maxtoch SN/Skyray instead. Fantastic light.
This one sounds interesting too.Has anyone compared them?
What is average runtime on high mode with an 18650 batt and with a 26650?
Is it the case that 26650 batts use the same charger as the 18650s?