I will buy XT-E leds and I will test them with my lenses.
I see in datasheet that exists XT-E S2 and S3 but they are not sold on FastTech.com.
Do you know where I can find them?
Thank you, but on AliExpress it is really more expensive.
For buying XT-E R5 1A it is more interested to buy them on FastTech (arround 5 USD for 5 pieces).
In fact datasheet specify S2 and S3 bin for the XT-E. It is for why I’m looking for a shop to buy S3 (else S2) bin.
I’ve found XT-E S2 1A on ebay but with a huge price (not acceptable) and I cannot ffind S3 bin.
Hello,
Just to give some information that may be useful for someone.
I’ve bought CREE XT-E LEDs and compared them to CREE XP-E.
Even if they have the same die size, I obtain a larger beam than with XP-E. The primary optic of the XT-E is bigger than the primary optic of the XP-E.
Then I tried tu re-use my XP-E Q5 (from flashlight). However, I obtained a strange behavior.
First I tried to replace the original flashlight driver but a simple voltage/current regulator in order to have only one mode (on/off).
For that I use this kind of power supply: Power supply
I’ve set it to limit at 3.2v and 1.5A, but when I connect the LED I can only mesure 0.2A…
By discussing on an other forum I tried to increase the voltage, when I’m arround 5 I’ve only arround 0.7A. After the LED burnt…
Does I miss something regarding the usage of these LEDs?
Yoann, with the limited information you are providing, can't really be sure what you're doing wrong… maybe those current measurements aren't accurate. Are you providing enough voltage leverage at the input?
You don't really need to mess with the voltage trimpot, leave it at full throttle.
Start with the current trimpot at a minimum/low value. Connect the emitter in series with an amperimeter at the output, or set it in series with a low value resistor where you'll monitor the voltage drop at its leads, so you can determine the current flowing through the load: V = I × R, thence for an R200 (0.2Ω), at 0.7A of current flow you'll measure 0.14V at the resistor terminals.
Mmm, wait, there's an R050 sense resistor on the board. Measuring the voltage at its leads will give you the current output value: 0.05V/A (I = V / R). As long as your voltmeter is accurate enough, that is. 
Cheers ^:)
P.S.: please, @#$% with those “local” aliexpress links, please post only global site links. Not only I do not want to open despisable & clownily translated item links, it also happens the friggin thing starts to think I “like” such a crap by default, and it forces me to use the “Go to Global Site” link to restore normal operating conditions. Thanks. 
Hello,
First, I’m really sorry for the link. I always use the global market (english) but sometimes it changes automatically chen browsing some links on the Web.
This is more information about the usage and connections.
The power supply module is supplied by a laptop computer switching power supply 12V (around 3A).
The led is connected in series with the Amperemeter to the power supply module.
For configuration of the module, I disconnect the LED and I can measure voltage and current (short circuit current) and set them with potentiometers.
I do not let free (no limit) the voltage) because when I tried my XP-E Q5 (it is what is wrote on description when I bought it) with the configuration 6V and 1A it burnt in some miliseconds.
Before removing the led orignal LED driver I’ve test the current throwing into LED driver and the LED. I mesure about 1.7A for a voltage of about 4V. Thus I know that the led can support this power. I only remove the driver without any changes on the led heat sink.
I also tried to test an CREE XP-L LED with a similar configuration (3.5V 1.5A) and I obtain a similar result.
I get 0.12A with the potentiometer connected in series.
Seriously? 
Damaged CC/CV module I'd say then, it may be outputting some nasty voltage peaks… 
Other than that, no idea at this moment. :|
Cheers ^:)
Hello,
I’ve potentially found the problem…
it seems that the problem come from the cables used.
I’ve changed cables by bigger ones and for the same voltage I obtain a greater current.
Now I can reach 1A with about 4V it is still not that the datasheet describe but this made a huge improvement.
However, if the problem come from the cable impedance, I still not understand how it can lead to LED destruction.
If I’m not wrong, in this circuit, cables can be assimilated to low value resistors. So yes, they contribute to reduce current flowing into the LED for a given voltage. They also have a voltages on their ends thus the voltage of the LED is not the voltage of the power supply output. I don’t understand why they burnt.