Great review JohnnyMac,thanks for the in-depth look at this light.I have been lusting after this light for awhile because of the great looks and the relative low cost for an xml-u2 flashlight but now I am a bit turned off.Quite confusing heat issue and output issue,my theory is that the smooth band at the top of the pill is not making enough contact to the threaded portion of the head,thus making the battery tube absorb the initial heat and then the heat would start to move to the head from the tube.I think giving the pill a larger area of contact to the head by way of copper ring in the head would solve this and eliminate the sag.Seems asthetics were a first priority and functionality last,shame because I wanted this light.
Nice review, JohnnyMac, thanks for posting.
Curses , Foiled Again !!! J)
Was really hoping for a big win with this light.
It looks awesome :heart_eyes: And from the pics , everything appeared to be set for success…
A bad reflector design could explain the beam.
The rest is confusing…
JohnnyMac a excellent review. 8)
I look forward to reading what you figure out and how you resolve the problem
Great review, great light 
Thanks 
If the pill design was like the Ultrafire M10 then this light would have been perfect.
The m10 pill screws into the body and head, so has 2 thermal paths whereas this light has the body path only.
That’s one heck of a good review, regardless of the outcome. Thanks for the effort.
I saw this last week and fell in love. I ordered 3 of them through Tmart and they shipped yesterday…. Hope they are good. I’m sending one to E1320 for modding……
Would a C8 reflector work ? Or an m10 ? I need throw not that much flood. Let’s make this light perfect …… It has potential !
Nice review Johnny. Very thorough.
You are a photographer as well!
I wonder if a ‘contact ring’ around the top of the pill would aid in heat transfer to the head ?
Manny, a C8 reflector is too wide and cutting it down to a correct diameter would make it too short, if I’m not mistaken. I started looking for a possible alternate reflector but stopped when I thought more about the heat transfer problem and didn’t know what to do about that. This needs a couple of fixes and people who know more than me to do them, but it does seem worth pursuing.
Would a Thrunite scorpion reflector fit ?
Very interesting review in true BLF spirit! Thanks so much for the huge amount of time you put into this. Frontpage’d and Sticky’d.
Great Review - Thank you …
Thermal sag !
Many variables : the basic’s , too much current .
As the emitter heats up , more energy goes to producing heat rather than light [ some call it thermal run away - and sometimes this can be terminal - for the emitter ]
So on a cold start the light puts out 800+ Lumen , but as it warms up the emitter can not maintain light output , as the emitter warms , more and more energy goes into producing heat , until a ballance is found …
Emitter gets no warmer … Then the output becomes steady …
This is why many lights that pull 3A or more may look great on paper , the reality is that once the light gets as warm as its going to get [ 30 seconds or more ] the output may be down to 500 or less lumen …
Why I run 1.4A drivers in my everyday users [ 450+ Lumen and little if any output sag and sane current draw ]
Sure , everyone wants a hot rod , but its not always the way to go …
Anyhow , a great review , really well done …
This light might be really nice with a 2A driver
You make a lot of sense, old! I think I may do just what you suggested.
Just received notice from Louis that Tmart has lowered the price on this light to $22.73. They also dropped prices on quite a few. Notable are the Skyray King for $59.63 and the TR-J12 for only $53. All shipped from the US warehouse. Nice!
Agreed - great comment, old. For practical use, the difference between 500 and 800 lumens is minimal - you can see fine with both. For my cycling lights, I prefer the more modestly driven ones. Steady output in lumens and longer run times. Even better is that plus an accessible turbo mode for short bursts. My N-Light ST50 is a perfect example: High is a perfectly adequate 500 lumens, a twist of the head and that makes a noticeable jump to 700 lumens.
I am glad someone else appreciates the ST-50. It is one of the best and most overlooked lights out there.
Mine shorted out…… It got hot and the reflector touching the wires melted. The light looks good and feels good, but can’t handle the heat ! I’m sending it to E1320 for a pill swap….