Flashlight/Host review: GearBest UltraFire XM-L2 1x26650 light

[Eudaimonium]

Hey folks, bringing you something new.

FIRST: I have gotten this light for a review for free from GearBest simply by asking nicely. Kudos to them

Now, moving on to the light. This is the one:
UltraFire Ceee XML-T6 Waterproof LED Flashlight
Their web page says "XML-T6" but on flashlight it says "XM-L2" so I'm going with the latter.

Normally it costs $14, but May from Gearbest said to share this coupon code with you:
GBF13CM

Boom. Now it costs $9.99.

I have received the light and played around with it, and there are two things:
1) Light itself is awesome. I am keeping this one as a light (will not be turning it into a laser).
2) It's one of the most host-friendly lights I've come across.

Pictures:





Fits very well in hand!




It comes with 18650->25560 plastic adapter. Is nice.


Now, the important part, the flashlight comes apart like this:





The head of the light seperates from the battery barrel, and is taken apart in half to the crown, and LED/driver assembly.

Crown further can have it's silver bezel removed to remove the glass and splash-proof GITD O-ring.

The LED/Driver assembly is massive, heavy in hand (lots of heatsinking potential). The driver pill is removable by unthreading it via two small holes.





This should make any electronics installation and heatsinking a breeze.

From a machinist, the host is very well built, and tailcap threads are smooth. As advertised, every thread is secured with lubricated GITD O-ring, making the light splashproof.

In short, I don't think you can really beat this both as a light and as a laser host for $14.

I will be stocking heatsinks for this light shortly. If you wish to pre-order them, I'm cool with that (will hurry up the designs and putting it up in shop if that's the case).

If you wanna buy the light, you have the link on top of the page.

Finally, the light itself is very bright, and beam is amazingly well collimated and narrow. It has your standard 5-mode pattern:
High-Med-Low-Strobe-SOS

Here are two pictures with light on and off using exact same camera parameters:




'Tis all folks. Thanks for reading! Let me know what you think of it.

EDIT: Update, new pictures of beam profile in fog:

 

[Cyparagon]

I don't think you can really beat this both as a light...

My problem with single lithium lights is they almost never have proper regulation, especially at this price point. They either have direct-drive with PWM for modes, or a regulation window that doesn't fit the discharge characteristics of a lithium cell.

Have you measured this at all?

 

[Pman]

I'm continually amazed at how bright very inexpensive flashlights are now. Haven't bought any for my house though as that's where I want to see some serious price cuts.

 

[grainde]

Hey thanks Eudaimonium.

Are you going to give any more info : Such as; what is the emitter XML T6, or XM-L2 (the XML will have lines or stripes across the emitter the L2 wont), does the sinkpad make proper contact with the host and is it connected with any sort of thermal medium. What are the currents of the modes to both the diode and at the tail cap (as Cyp mentioned earlier it maybe DD on high?). Any ideas on the driver, is it PWM and is there an audible hum, or buzz when in low modes? What is the output like on a blank wall with different exposures - any rings or issues with the output is there a hotspot and does the light throw well? Any idea of the lumens? Lastly did you check to see if it is actually waterproof?

Glad to hear youll be making heatsinks for these, it looks like a nice little host.:beer:

 

[Eudaimonium]

My problem with single lithium lights is they almost never have proper regulation, especially at this price point. They either have direct-drive with PWM for modes, or a regulation window that doesn't fit the discharge characteristics of a lithium cell.

Have you measured this at all?

Hmm, what exactly do you want me to measure? So far I've only tested the light with 1x 26650 cell, looks nicely regulated to me (though it's a fully charged cell).

Hey thanks Eudaimonium.

Are you going to give any more info : Such as; what is the emitter XML T6, or XM-L2 (the XML will have lines or stripes across the emitter the L2 wont), does the sinkpad make proper contact with the host and is it connected with any sort of thermal medium. What are the currents of the modes to both the diode and at the tail cap (as Cyp mentioned earlier it maybe DD on high?). Any ideas on the driver, is it PWM and is there an audible hum, or buzz when in low modes? What is the output like on a blank wall with different exposures - any rings or issues with the output is there a hotspot and does the light throw well? Any idea of the lumens? Lastly did you check to see if it is actually waterproof?

Glad to hear youll be making heatsinks for these, it looks like a nice little host.:beer:

Hey man,

I can take a detail picture of LED if you want, for now you can read the LED numbers from the pic.

If by sinkpad you mean the surface on which the LED is sitting on, it's the same part as the entire head (machined out of same part). So heatsinking on LED itself is epic.

No audible anything when light is on. Output on blank wall is uniform and the "throw" of is very nice. I can take pic of outside street illuminated with this light.

Idea on lumens? Not a single goddamn clue.

And no, I have not actually checked it's waterproof, but I have never claimed it to be. I only said "splashproof". I'd say it can take a soak in the rain, but not any significant water pressure from being submersed a few feet in water.

 

[SilverFire]

Good review, +rep

I think it can be difficult to do super detailed flashlight reviews with limited equipment. Cyparagon pointed out a lot of the things missing in my first flashlight review. Most of which I had no idea I needed. And I never knew there was such thing as lux meters in the $20s-$30s. So I may not be doing flashlight reviews anytime soon cause of my lack of knowledge on how to measure certain things :crackup:

 

[RYDorDIE278]

Its quite a bright photo of the LED but it looks more like a XML2
The XML has a green backing around the dome and XML2 has a silver backing

Nice Review!
CheerZ:beer:

 

[grainde]

I can take a detail picture of LED if you want, for now you can read the LED numbers from the pic.

The numbers are on the sinc pad and may not actually reflect what emitter you have. If you look at the die and it has lines its an XML if it is bare then its the XM-L2. I will hunt for a pic for you.

If by sinkpad you mean the surface on which the LED is sitting on, it's the same part as the entire head (machined out of same part). So heatsinking on LED itself is epic.

The sink pad is the metal board the led is soldered to, the alu disc in the pic. Its good that the mount for the sinkpad is solid but it wont help if there is nothing to help transfer the heat away from the pad and to the host. Hence why I was curious whether there was any thermal compound under the pad.

No audible anything when light is on. Output on blank wall is uniform and the "throw" of is very nice. I can take pic of outside street illuminated with this light.

Ok cool thanks.

Idea on lumens? Not a single goddamn clue.

Ok just thought Id ask. Maybe you had a light meter, or another tested light to make a rough comparison to. Anyway not really important most Chinese lights are completely over rated, but if there is an XM-L2 in there and running at + 3 A you might get + 800 lumens. We could check that with the current at the emitter or have a very rough guess from the tail cap current - depending on the type of driver used.

And no, I have not actually checked it's waterproof, but I have never claimed it to be. I only said "splashproof". I'd say it can take a soak in the rain, but not any significant water pressure from being submersed a few feet in water.

Ok its advertised as waterproof, but I understand if you dont want to risk that! :na:

:thanks::beer:

Edit: Here is the XML - notice the lines:

and here is the XM-L2:

 

[Cyparagon]

Hmm, what exactly do you want me to measure?

Use a bench supply and vary the voltage and see how the current draw changes from 3 to 4.2V.

 

[Eudaimonium]

@grainde: I checked the LED surface, it has no lines, so true to the host's script it's XM-L2.

@Cyp I'll take some current measurements tomorrow. Don't have a bench supply but do have batteries of varying charge levels.

 

[dubious speculation]

My problem with single lithium lights is they almost never have proper regulation

You're going to be extremely hard pressed to find a budget light that is completely regulated. The cheapest route would be to purchase a light that has a linear regulated AMC7135 driver. But even then it will only stay in regulation as long as the cells voltage is above the vf of the LEDs. And when you're running an xml2 at 3A with a forward voltage of 3.6v, an 18650 can only provide ~800mah of runtime until it reaches that voltage.

The best way would be to ensure that the driver can operate in regulation regardless of the operating voltage. For example a buck driver with 2S cells.

The sink pad is the metal board the led is soldered to.

Sink pad is technically a brand of LED stars. Most definitely this just an ordinary aluminium star without a DTP.

I can take a detail picture of LED if you want, for now you can read the LED numbers from the pic.

The led appears to be an XM-L2 based on your picture.

No audible anything when light is on.

It would also be nice to know if there is any visible PWM in the med and low modes. It's very easy to qualitatively determine this. Simply turn the light on and quickly wave a ruler or something similar through the beam. Ideally a PWM controlled light should operate at about 9KHz in order for it to not be visible. The light below represents a PWM of roughly 480Hz, which is quite slow.

Thanks ToyKeeper for the pic.

 

[Eudaimonium]

@Cyp,
With 4.0 Volts charge on the battery,
High mode draws 1.35 Amps,
Med mode draws 0.91 Amps,
And Low mode is 0.51 Amps.

I'll see if I have one at 3 Volts (or I'll just discharge this one )

@Will, I have used that method (awesome idea), and I can see NO PWM modulation in Low mode at all, it appears to be completely continuous.

 

[grainde]

@Cyp,
With 4.0 Volts charge on the battery,
High mode draws 1.35 Amps,

Well at that current (and price anyway) it shouldnt be a boost, so its probably a linear and roughly what the LED is getting. This means you could drastically boost the light output with a better driver running at say 3 A Currently, the way its under-driven, youd be lucky to get 400 lumens. :beer:

 

[Eudaimonium]

Well at that current (and price anyway) it shouldnt be a boost, so its probably a linear and roughly what the LED is getting. This means you could drastically boost the light output with a better driver running at say 3 A Currently, the way its under-driven, youd be lucky to get 400 lumens. :beer:

No kidding, XM-L2 LED can take that?

Ooh, pocket sun, huh? I just MIGHT re-work it. Preferably remove modes along the way. Not a fan.

 

[grainde]

Yup no problem at all provided you make sure you use thermal paste between the pad and the host. IIRC they can actually take up to around 5-6 A, if on a copper pad and very well heatsinked. FYI I have several running at 3 - 4 A for more than a year now and they are going very strong. Here are a couple of threads with builds I have done with the XML/XM-L2 diodes:

http://laserpointerforums.com/f42/poppas-xml-t6-mod-pic-heavy-80447.html

http://laserpointerforums.com/f42/pics-added-sipik-98-4-amp-flashlight-mod-82310.html

The only issue running them this high on direct drive (or higher current linear drivers) is the voltage drop from the single battery when at these currents. A buck from 2, or boost from 1 battery, would therefore be better. The XML is just ok as the Vf is not that high at 3 A, but the XM-L2 has a higher Vf (see the IV curve) at this current and so you start to have issues above this with the lack of V under load from the battery.

Vf vs current for XM-L2:

I also have a couple of new builds with MT-G2 emitters and modified AMC drivers running at 8.4 V and 6 A on copper Noctigon pads. Those are bright When I get a little time I will post a detailed build thread including how to do the zener/resistor mod on the driver. :beer:

Edit: Heres a lumen vs current graph for the XML:

and here XM-L2:

 

[Eudaimonium]

Need to give more rep before giving it to you. I owe you + 1.

This is some AWESOME info, I will make sure to put down the upgrade project on my To Do list. This looks great.

So even the modding possibilities on this light are beyond what I would've hoped for for a dozen bucks.

This is great.

Regarding the driver, I can easily use the plastic adapter and use 2x 18350 for two lithiums buck driver setup.