As far as I have seen, those new China-LEDs are two steps back in terms of efficiency.
Sub 100Lm/W in times where even High Power LEDs are usually over 150Lm/W is not the right way
How do you know that? Have you tested it? I understand why the SFN55.2 might not be efficient with it’s very low vf. Combine that with a linear driver and yh it’s not gonna be great. At turbo it seems pretty similar to 7x osram 2mm. Pulls about the same current with similar output.
I tested the SFN55.2 in a NI03 and got near makes no difference 29 amps at probably 3.3-3.5 volts (6912 conservative Lumens) with the included 26800 battery. I’m thinking of trying a 30T to see if I can get more since I know that 26800 is really working hard at that drive current. Until someone officially tests one in a sphere to prove it, I’ll put my money on the table that the SFN55.2 will be as bright (or brighter) than a 70.2 with less power consumption. Take off the dome and it will be even less output.
For some reason, the luminous area values in that chart seem to be way off for at least some of the emitters.
SFT70 = 6.25 mm²
XHP35HI = 5.8 mm²
SFS80 = 5.2 mm²
Interestingly, the lm/mm² values seem mostly in line with values in my tables. Two wrongs make a right?
Im really torn on buying this new FT03 (mateminco version) with the SFN55.2
Can anyone who has a light with one of these LED's share any information? is it interesting / WOWing / fun? I have all three LED variations of the FT03 (one with SFT40 not sst40), any reason i should even be considering the SFN55.2 version?
If so, better to run a Molicel P42a or one of the QB26800 batteries i have laying around? I would need to buy another battery tube though, thats another $10.. thats $60 for an FT03 that does (7000?) lumens. Is that compelling? I don't know.
Well, if the NI03 is any indication of performance to the ft03, I say get it. You won’t be sorry. I don’t think the heat sinking is as good though on the ft03 so your duty cycle on higher modes will be lower. Use the 26800. I really like that cell and it’s probably diminishing returns to use a P42A.