White flat and "Green" flat have the same thermal resistance, so max. currents should be similar, green flat peak could be a little bit higher (0.5-1A) due to higher efficiency and lower phosphor loss.
So I think this confirms your white flat test was probably with sub-optimally reflowed LED since I got 5.75A peak, almost 1A higher than what your test shows.
Yes, I considered that. Funny thing is that this time the reflow was done with less care (more solder) than with the White Flat test. So I do not rule out that this difference is real. I may re-do the White Flat test although it is less fun to re-test stuff than something new :weary: (and it costs me another led, ).
How about this: I'd like to send you 9 LEDs, 3 soldered by me, 6 bare + 6 3030-20 DTP boards + small amount of lead free solder. You should solder 3 LEDs with your lead paste, and other 3 with my lead free paste.
So you could finally test lead vs. lead free solder,and also see if soldering technique has any visible effect, white flat is best LED for that test since it has smallest thermal pad (3x1mm) and highest power density (W/mm2).
3LEDs for each test is to eliminate "luck" during soldering and LED thermal resistance variance.
That is quite a few hours of testing but it sounds like that will generate some useful data, let’s do that. But we can not set a hard deadline for this, having a family, and with always the possibility for the need of extra care for my son, my hobby-time can spontaneously evaporate at any time, so things must be postponable.
Looking at datasheets, two graphs (output vs current and output vs temp) also show that green flat looses output slower than white flat at higher currents and higher temperatures, which is in agreement with djozz' measurements(left white flat, right green flat):
One interesting thing is green flat output reaches max. at ~40-50C, but it's only 1-2% higher compared to 20C.
Green flat is a little bit closer to 2.5 than white flat, difference is small, temperature has much more visible effect, at 100C white flat is at ~89%, green flat at ~94%.
I just put the second led that I got in my GT micro. I know, this nice flashlight deserves better than green, but I could not resist. The steps I took:
*Unsoldered the ledboard, unsoldered the XP-L Hi, added a little solder paste, soldered the Green Flat on the stock board
*had to use a new centerpiece with square cutout to center the led. Sanded it the same thickness as the stock centerpiece, made the cutouts with a scalpel to fit the Green Flat 45 degrees rotated.
*Reamed the reflector hole to fit the new slightly larger centerpiece. Can’t go back now to stock
*Closed the head and test: perfect focus on first try , also tells that Lumintop did a good focussing job
*did a spring bypass on the tail (with tailboard in place).
Wow, that is a bright green spot. I carefully measured it (purple Efest battery, 30 seconds) at 7 meter with my best luxmeter: 177 kcd. I measured a few known lights to check the luxmeter (it reads high with an almost depleted battery), and it reads correct. The output (purple Efest, 30 seconds) I measured at 930 lumen, good enough, that would be between 3.5 and 4 A.
It does well outdoors as well, spot aimed at about 70 meter.
So now I scratch my head what to use it for. Showing off to my son I guess :party:
177 kcd in green, housed in a Micro... Wow! I want one for my 1504 - cant' imagine what it would do 500-600K?
Now I ave to get a couple more Micros. Are we seeing way better #'s than in a D1? I oculd only get in the 40's out of a D1, but didn't try any of the flats in one. Sliced SST-40 got in the 40's for me.