No… Enderman is not quite right here.
The answer is it depends on used battery. Anything in Samsung INR30Q class is not good for White Flat cause they will pull from 7-8A in DD mode significantly downgrading lux performance.
With White Flat you want to stay somewhere at 5.5-5.8A current draw. So use Sany GA, LGBD1, or any other low current cell that will not pull more than 6A out of emitter.
I thought 4.5A is the sweetest?
It depends on how good your heat path is. If your reflow is done well with enough but as little as possible solder, on a DTP board that is thermally well mounted on a good heatsinked flashlight body, then 5.5A to 6A may be the sweetspot. But if everything is less perfect, this led (small die, high heat) is very finicky about that and will have its maximum performance at lower current.
bought 3 of these leds from Led4power
put one in my 2016 cometa
meters went from 800 to 1216m, it’s like a laser!!
measured 4.5A at the tail
Thanks djozz. Is there other test chart done by you or others? I think we should update first post with link or chart.
I only know of my own test and led4power’s test, and they are both in the OP.
To me, judging by the graphs i’ve seen, it seems to be the maximum reasonable current.
Above that you hardly gain any output.
It will age the LED faster and mainly more heat will be produced.
Vf will also be higher.
The difference between 850 and 950 Lumen is not worth it i.m.h.o.
Except that this led is exclusively about throw. It has no great tint, a low CRI, a bad efficiency compared to bigger die leds. The reason to use this led is throw, also that last bit, and you want to be as close to max as you can without killing the led.
You should only do this if you only use it for a few seconds at a time or the flashlight is very large and never gets warm/hot. As soon as the flashlight becomes warm, the LED will overheat when driven at it’s absolute max (who’s was measured when cool).
In my kind of led-test the led was already pretty much warmed up when arriving at max. But my tests give no clue whatsoever about the lifetime of the led.
I get the dragster attitude, i get the fun of that, but it’s just not my attitude.
I want my lights to be able to work on full output for a long time, and if possible, with decent efficiency.
With this low Vf of the ‘White Flat’ this can be achieved while still having amazing throw.
I will not win the light meter candela race, but i wonder if the difference between 850 and 950 Lumen will be noticeable by human eyes.
In fact, i’m thinking about running them at 4 Amperes maximum actually.
It will have to wait for now though, i’m busy with the BLF scratch build.
Leave them alone burning down their white flats Jerommel, some folks here seem to be adamant devotees of their MOSFET DD misdrivers.
Cheers :-)
Ah thanks!
:laughing: :+1:
Well this is watt I was alluding to in this intently “loaded” question and I was waiting to see watt replies if any it generated. Yes the latest version Osram KW has higher lux than XPG2 but with caveats. And they are significant caveats in an ever more popular FET driver world. Osram may improve the KW’s current handling abilities in the future and when that happens well it’ll definitely without caveats be The King.
Past certain amps the dedomed XPG2 S4 2B today is still King IMO. Butt let’s face it. LEP technology currently lux surpasses all LEDs out there with all 1:1 input factors considered. And the thing is it still has room to improve. 
LOL 
anti MOFSET propaganda
Guys this is not Black Flat it is White Flat… Seems like that Osram added something like wire or two to improve properties.
I see no problem in using it in FET DD setup but of course with low current cell .
And Barkuti. I vote for MOFSET DD Setup with Sanyo GA 18650 cell :+1:
That configuration will run 5.5A (at 4.2V) > 3.3A(at 3.4V).
New series of Osram seems to be very robust emitters. Soon you’ll see that there are emitters that can pull over 12A without burning led or angry blue 
So yes i vote for FET DD configuration but with low current cell (there are plenty of them on the market). No need for spring bypasses any more, no need for stacking chips, so it is just a cheap - budget configuration at the place where Frugal meets flashlights 
Nothing against linear or buck/boost drivers also. Just bring them on…
After all I use linear driver as a host for my nice little diy 1.5$ Djozz driver. Some guys like regulation while some really don’t have any need for that. 
Barkuti this pic is just for you (I am preparing whole FET driver army )
Hope you will not hate me now :laughing:
Ya, I kinda get the feeling Barkuti sorta doesn’t like MOFSET. :laughing:
It’s not though, the black flat was still better.
Unless you’re talking about how at a constant voltage the XP G2 will draw less current than a white flat and therefore not overheat as quickly resulting in higher performance.
But that’s not really a fair comparison here.
You’re basically letting one LED overheat and not the other.
The great thing about low Vf is that you can drive it at it’s peak performance for extended periods of time using a regulated driver instead of an inconsistent dim, bright, and dim that DD would give with an increased risk of killing the LED.
There’s really no reason to do DD anymore. Drivers that can supply more current than necessary already exist.
Ok granted I was being a bit unfair heat-wise in that it can take ‘sloppy’ abuse better for higher extended performance. BTW so the Black Flat can take DD generated heat (abuse) better than the XPG2?
Well, if that isn’t some backwards thinking, I don’t know what is! But no worries, you’re not the first one, nor will you be the last. :person_facepalming:
To clarify for the folks watching at home: More wattage NEVER means more performance! In the past, emitters HAD to be pushed almost to their breaking point to reach peak output. So, it became a common “shorthand” or a “rule of thumb” to say that more watts means more performance. But, it technically has never been true. These days it’s less true than ever, since the space between the end of the performance peak and the end of the emitter (failure) has widened considerably in lots of cases.
So, to say “Past certain amps the dedomed XPG2 S4 2B today is still King IMO.” is to show a misunderstanding of how this works. Did you not see that it was said that the “White Flat” will out-perform the dedomed XPG2 S4 2B while pulling about 2A LESS? Who wouldn’t want that? Great performance PLUS better run time! Sounds like a winner to me! 
:+1:
Once again, in case you missed it, the dedomed XPG2 S4 2B REQUIRES more wattage than the “White Flat” in order to perform, and yet it still doesn’t perform as well when compared to the peak performance of the “White Flat”. The reason it MAY perform better at high wattage in a DD setup is because the “White Flat” is losing performance by that point.
About those DD drivers too: The reason they were developed years ago and became so popular is again BECAUSE the emitters had to have high wattage in order to perform at their “best”. Now that more emitters are being introduced with peak performance well BELOW peak wattage, I predict that DD FET drivers will lose popularity. It won’t happen because of the crusades of a few Anti-FET members, but because most of us aren’t looking to idolize FET the way we’re being accused of in the first place. We just want max performance. And if we can have better run time as well, we won’t hesitate to throw DD FET drivers off a cliff in order to reach for the next thing. :innocent:
Yes I am referring to ‘abuse’ performance not efficiency performance. It performs better when 1:1 abused (direct driven) particularly with higher current type batts such as the 30Q.
Never meant nor intentionally implied that more watts equals more (better) performance.
Many LEDs will continue to be FET abused for the near future until all of us become Barkutified Enlightened and the Osram KW mentality goes modder mainstream. I agree with you on the trend going that way though. LEP efficiency technology alone will further reinforce it.
Barkuti is right. We prolly need to start Seeing the Light better. :laughing: