Just in case anyone is looking at this one, the 9 volt mt-g2 is only rated for a max of 2 amps, so a 3A driver would be overdriving it by ~50% already. Heck, the 36v one is only rated at 500ma.
Really??? I thought this monster had to be driven at well over 3A. I guess I figured it was the same as the 6V model. Good to know. 
Cutter doesn't even have the 9v,just 6 or 36,this is going to be a real pain to find a driver for.Trial and error will be the way to find out what works best,I,m going to try a 5 amp sst-50 driver@8.4v with the 9v mtg and see what happens.Just have to wait for the 9v to be available.
I think you guys are forgetting the simple fact that measuring the approximate output of an LED by amperage alone isn’t entirely correct.
We can generally get away with it in this forum because normally all the LEDs we use operate at the same voltage, but these don’t.
Volts X Amps = Watts
So, for the MT-G2, it only makes sense that the three versions are as listed:
6V at 3A = 18 Watts
9V at 2A = 18 Watts
36V at .5A = 18 Watts
For an XML:
3.1V at 3A = 9.3 Watts
FYI, because I was curious, they list the MT-G2 maximum output:
1987 lumens at 18.5 Watts = 107.4 lumens per watt
And the XML maximum output:
1040 lumens at 10 Watts = 104 lumens per watt
So efficiency is pretty similar, it’s just capable of a much higher input, thus allowing far more output.
To me, this LED means we now have the capability of a much brighter flashlight in a single LED format. I’m excited.
Now we need a suitable driver.
Yes, MT-G2 has more Lumen/Watt. but bad for brightness/die area.
So MT-G2 is suitable for Flooder flashlights.
I’m still waiting for mass SBT-70/SBT-140 or CREE round LED for make Thrower or Flood to Throw flashlight.
I fitted this driver in my torchlite build, I get a 3a tailcap reading on two keygos 26650’s (not the best cells in the world) its comfortably bright on high and low is wickedly low considering.
pop over to the torchlite thread by edcplus ti see what we all tried out.
Subscribing, cause all this driver stuff makes my head hurt.
The ideal is, of course, always sold out here.
The overdriving one, is more expensive and needs substantial heatsinking, I would imagine.
FT has a 5 mode version:
http://www.fasttech.com/products/1612/10001998/1143104-2-3-lithium-5-mode-3a-led-flashlight-driver
LCK-LED has a similar/identical driver with just Hi/Med/Lo (also it is the same driver as KD’s “Super Output” buck driver)
http://www.lck-led.com/19mm-3000ma-driver-modes-p-501.html?cPath=135
I do wish FT would stock a 3 mode version.
Any buck driver rated for the voltage you will be supplying should work fine. The closer the supply voltage to the vf the better. The 6v mgt2 vf climbs as the current climbs. So more than 7v if going over 3 amps. I have used that cheap 3T6 from Manafont with great success. Drives around 4.5amps stock. That was with 2S 18650’s.
Right now, I’m using just straight 7135’s with manual switches to control current and have 6S nimh cells. So 7.2v total. The cells are 4/3AF’s. Works great.
Don't forget the HBFlex... the only 3-amp-capable boost driver I know of - but the low end of the input voltage range is too high for a single cell (too high for two cells, really, though you might be able to get by), which is a shame.
Does anybody know if the TaskLED drivers, specifically the H6Flex, can survive with LEDs in parallel? I know that's the 'wrong' way to do it, but it usually works fine in the non-theoretical real world.
the driver won’t care about the LEDs wired in parallel, although the risk of an imbalance in Vf and current draw between the paralleled LEDs increases with current I believe. That’s just theoretical though, I’ve no practical experience of it.
So, how do you calculate total/individual amperage with LEDs in parallel run off a common output? For example if I used the H6Flex in the triple MTG2 build with 4S cells and LEDs in parallel, vs. the original plan which was HBFlex boost driver with 4S cells & series LEDs.
(numbers with the HB boost: cell voltage 12-16.8v in, total series Vf of ~18.9v; w/H6 buck: 12-16.8v in, parallel LED Vf of 6.3v)
I have no measurements at all as I have only just got my pill together with driver and led but can confirm that this driver will run the MTG-2 hooked up to a couple off trustfire 26650 at 3.8 volts with no load on them. The led is direct to copper and it is the quickest I have ever had a pill get hot. The mode changes still has that pause between them as reported elsewhere.
Cells in series or parallel? I have one of those drivers on the way, too.
Series.
Crap! :( Was hoping for some actual single cell boost action. Was it you or somebody else who reported that driver didn't like running off a single cell?