sorry - solar storm T3 -> my review
Ah! I should have figured that out myself... Doh!
Hmm... What battery are you using? Pana NCR18650B like in the review of that light?
Because with a single XM-L2 (instead of three XM-L in parallel) that may be the issue.
These drivers deliver only the highest amps with the hottest batteries.
For reference I have made a set of measurements tonight.
The same batteries were used throughout this test and they were not recharged in between.
First set is through a similar driver as the one you have. This test setup's wires includes
30 cm 2,5mm2 cable with alligator clips
12 cm 18 gauge silicone wire
A ~80mm solid copper shunt resistor of 1,5mm2 wire for measuring amperes
Another 12 cm of 18 gauge silicone wire that are mounted on the driver.
Panasonic NCR18650B. Battery is about 3 years old but otherwise working well as daily flashlight battery. Resting voltage 4,14V 3,5 A.
Unprotected Sanyo 2000 mAh laptop pull. Battery is about 4 years old and working well as daily flashlight battery. Resting voltage 4,14V 4,1 A
Sanyo IMR 1600 power pack pull. Battery is about 5 years old and working well as powersource in hot lights. Resting voltage 4,13V 4,5 A
Last set is true direct drive. THIS setup's wires includes
30 cm 2,5mm2 cable w. alligator clips
12 cm 18 gauge silicone wire
A ~80mm solid copper shunt resistor of 1,5mm2 wire for measuring amperes
Panasonic NCR18650B. Battery is about 3 years old but otherwise working well as daily flashlight battery. Resting voltage 4,12V 3,5 - 3,6 A. Meter shifting constantly.
Unprotected Sanyo 2000 mAh laptop pull. Battery is about 4 years old and working well as daily flashlight battery. Resting voltage 4,14V 4,2 A
Sanyo IMR 1600 power pack pull. Battery is about 5 years old and working well as powersource in hot lights. Resting voltage 4,12V 4,6 A
To me that indicates that if you are using Panasonic NCR18650B batteries the 3,5 A is probably what those batteries can deliver. It is what my similar batteries can deliver at least.
This is due to the high Vf requirement of the XM-L2 VS the 3 parallel XM-L in that solarstorm light where you tested the battery.
Furthermore a XM-L2 has a higher Vf requirement if mounted directly on a copper mcpcb like that Sinkpad you also got.
So:
parallel emitters -> higher amp reading
XM-L VS XM-L2 -> higher amp reading w. XM-L
Hot batteries like the Sony VTC5 or other IMR batteries -> higher amp reading
Unprotected batteries -> higher amp reading (this is due to the voltage drop across the protection circuit. Safety bites ;-) )
I am sorry if all this comes across as if I am trying to school you. Reading through this wall of text I just wrote I can see how that could be the case.
I am not though. Just trying to get to the bottom of this and pursuing a possible reason.
so 3 emitters can suck more amps from one battery than 1 does?
and thanks for your testing!
I am sure that’s a lesson not only for me…
I had time to play a bit…
1 cell 3,5 A
2 cells 3,7 A
but since I don’t have high Amp cells ATM I keep it as it is.
shipping back and forth is more money spent than the driver is worth.
Hi M4X.
Just FYI
I just got some Samsung 20R batteries in that are new and with those I hit about 6 amps on my test rig.
source / price? 
Oooops. Sorry I did not get back to you sooner. I just saw this.
I got a local deal on a Dewalt battery pack from a foreclosed business locally. Brand new. Comes to about 6 Euro per cell.
i tried with one of my latest pulls
gave me 3,9 A
(3,6 with other unprotecteds i used above, 3,3 with protected pana NCR)