M21H weighs 25% less so I’m guessting 1200-1500lm range.
M21k with LHP73B and 20a buck driver: Acebeam l35 killer?
I don’t know about killer, but right now if you want a single LED 6000 lm light with warm CCT and fantastic Duv 0.0000 tint, LHP73B 4000k is your only choice.
M21K + LHP73B has other attributes, like “30 buck” 
, insane sustained brightness for such a smallish light, and fantastic throw, but first and foremost is the quality of the beam color IMHO. This is what sets it part and I suspect was what @Simon_Mao was aiming for.
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That won’t be the case in a few weeks 
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Nightwatch LW55 vs Convoy M21K? Can’t wait for the battle royal . Pls let me know when this “monster” is released.
Cool white and reflector in the nightwatch are enough for me to prefer the convoy
If you want the initial wow factor the LW55 is slightly brighter and it potentially throwa slightly better. But if you want high sustained output and nice tint Convoy takes the crown.I’d even consider the L21A with LHP73B for its lovely smooth floody thrower beam.
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No no. I wasn’t even mentioning the LW55 V2.
I was referencing the DDH M4C NBD110 4500k that you’ll find around here
Yep. I have one on the way. Outside of the wayyy too rosy tint, it looks very good.
As I’m waiting for the M21K LHP73B, I keep thinking about SFT90 version or a modded SBT90.2 flavour of it.
All other aspects aside, I was curious how these three could compare thermally.
So I looked at @koef3’s tests of the three (the SBT90.2 is not on the master list).
From the 1Lumen review of the LHP73B I figured the TIR efficiency may be some 85% and assumed it applies to other emitters. Then also assumed that the output current to the LEDs on turbo and super-turbo is the nominal 10 A and 20 A (as @thefreeman measured above in this thread for LHP73B) for all on a fresh tabless battery.
| Output/Power | LHP73B | SBT90.2 | SFT90 |
|---|---|---|---|
| lm @ 10 A | 3350 | 2700 | 2900 |
| lm @ 20 A | 6000 | 4250 | 4250** |
| W @ 10 A | 30 | 31 | 33 |
| W @ 20 A | 63 | 67 | 78** |
** May not happen in reality as discussed below.
It looks to me that on 10 A turbo they may all heat up at similar rate but the SFT90 on 20 A may be pretty short-lived with the extra 15 watts to dissipate (if the driver can indeed deliver 20 A to it at all).
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Does this mean the SFT90 Vf at 20A is 3,9V? Then it doesn’t seem feasible, at least not for longer periods. The driver is buck only, and according to Mooch’s test even the Reliance RS50 drops below 3,9V at 20A in about 10s
P.S. Just noticed the “Please do not share or post”, removing the image but leaving the link to forum post itself
One clue that you may be right is that in @Weerapat_K’s VDOs going from Turbo to super-turbo makes seemingly less brightness difference with SFT90 than with LHP73B. But then (I just looked at my own table above) it probably should even if 20 A at 3.9 V is indeed delivered to the LED on super-turbo…
I think either way the the SFT90 may not be the best choice for this light.
But there is also another detail by @thefreeman here. Not that I understand it, but if the voltage is first boosted and then bucked, maybe 3.9 V output is possible?
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Wow, that does seem promising, can’t wait for @thefreeman 's confirmation or negation. Would that mean that in some bizarro world it could run on eneloops? 
Maybe wait for the new round emitter from Simon? Should be available in different CCTs.
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The small boost converter is only for driving the mosfet at 5V instead of the battery voltage (4.2~2.8V), in order to decrease its ON resistance. The driver is only buck and as @horzuff said the high Vf of SFT90 will limit the current.
That warning must have been added by mistake as it’s normally only present with Patreon exclusive stuff (which this test isn’t, other tests on e-cigarette forum don’t have the warning)
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By “driving the mosfet” do You mean opening/closing it? And nothing to do with actual output to LED?
As for the warning, You’re probably right 
Too late… :-)
