There is a wide variation in duv for different bins of LH351C/D, but slicing them always lowers the duv and temp, and makes them significantly more throwy than stock.
Here is some test data a user on r/flashlights got on results from slicing the domes with various thickness washers as guides…
Did you see loneoceans new Lume X1 driver? That seems like a driver that almost meets your requirement!
For led, this is a newer led but I am not sure how it compares with other leds since I have not seen it before in a flashlight https://www.lumileds.com/products/high-power-leds/luxeon-hl2x/
There is data and discussion in this thread.
They would be okay for a muggle light with a regulated driver and a frosted/pebbled TIR. Otherwise they are DOA for us I think. Maybe in a D18 or MF01 they’d be good, but that’s really stretching it. I have 90 CRI versions that are to arrive in late April, but I’m already wishing I could cancel the unshipped units.
Contactcr did a few test on several different binned LH351D’s and posted them here.
My favoorite is the SPHWHTL3DA0GF4UPP6 90 cri he tested from Digikey.
Shave it for a tighter beam and lower duv with slightly lower cct.
They are still available at Digikey
If you prefer 4500k I would suggest 90 cri 5000k shaved or dome on for more output.
Couldn’t tell you which bin is best as most of mine came from AEDe group buy with a good tint.
I have seen over 1000 lumens in a 16340 single led light with a little over 3 amps using a 5000k 90cri LH351D with dome.
Pretty sure that one was what we call the dogfarts bin
The dogfarts bin seem to have been a popular bin as I have seen it pop a few times here.
I prefer shaved for the tighter beam and better tint but if your lumen hunting leave the dome on. 
Has anyone tested the DUV in Convoy’s LH351D 5700k?
Yeah, I saw that driver, I am always a fan of Loneoceans drivers. It is really close to what I want but the 40w limit is just a bit lower then ideal. My XP-G3 setup was pulling over 60w+. I could make 40W work I suppose (or possibly jack the output a bit) but then there is the issue of it not being a 17mm driver and I don’t know of a 21700 triple EDC host.
Thank you Mr. JaredM. I agree unfortunate that it seems like this led has bad tint shift. Hopefully may be Cree or Samsung will make some new update to the led soon, like XPG4.
This is a bit confusing to me. I think I understand that people like 'turbo' mode. But when I think about it, normal house bulb (led) is already 8 to 15W. I find it a bit interesting we expect 60W from small hand held flashlight like single 21700 light, because it will never sustain 60W for more than few seconds before it begin to overheat, then the sustained output is maybe 5W. Maybe 60W make more sense for big flashlight with many battery.
For my opinion, I think I prefer maybe less 'turbo', but then better sustain output and runtime. As example, 7W for 2hr with 40W turbo and Anduril is better for me, than 5W for 2hr with 60W turbo. Boost driver make it possible to do series tint mixing led. This is something I am curius to try. I think Loneoceans say he was trying to build a flashlight with 21700 with triple led PCB on the Lume X1 page.
People underestimate how long a well built EDC can handle turbo. I did quite a bit of testing on mine and I could easily run turbo for 90-120 seconds before it got too hot for me. I found this to be ample for the vast majority of situations that I needed turbo as I would step down to a lower mode once I had scanned longer ranges to see what was out there.
With a 21700 version of my EDC I could easily see that turbo time increasing to 120-180 seconds.
The sustained power will remain the same regardless of what the turbo is, turbo just gets it to the peak temperature faster. The amount of heat the host can dissipate is fixed for a given ambient condition.
Mostly without at least 2500+ lumens on turbo I find myself hunting for a higher mode way more then I would think. 40w is just enough to reach around there on an XHP50.2, so it is something I am considering if I can find a good tint XHP50.2. More output would be better naturally though.
The biggest issue with the boost driver in that thread is it won’t fit my EDC and I don’t know of another host that would work. If someone knows of a 21700 host with a similar build to the convoy’s, I am all ears. Surprised Convoy has not made one yet to be honest.
The s21b is pretty close to being a 21700 s8. Shallower reflector and integrated shelf though
What’s the Lume X1 size? The S21A uses a 20mm driver, I suppose the S21B does as well. The S12 uses a 22mm driver, but for a triple.
Ok, now you have my attention. Looking into that, seems like the S21A has a pill but no fins, the S21B has a fixed shelf but includes fins. Those little fins are surprisingly effective.
I would want to swap to a TIR optic so I need the brass pill.
Hmm, if that $1400 stimulus comes though looks like I will be ordering a few things from Simon. Finally something worth considering as a replacement for my EDC.
I could not find specs on the drivers that come in these lights, anyone know who made them? What current they output or what firmware they use?
Although at this point I should almost just see if DB custom is still around and can be talked into customizing a 21700 host for me lol.
Is the x1 even a product yet? Last I saw it was just a single driver that was made as a proof of concept for a particular light. I did not see any generic drivers being sold or plans to build them?
So a bit green then.
Mr. Texas_Ace, I agree with the need for high power turbo, but please let me explain what I mean. I have two main idea:
For triple 3535 or 5050 led, if you use high cri, even with fet it is difficult to run much more than 3000 lumen.
For small single battery flashlight, I don't know any flashlight that can run at 90s at turbo (let assume about 3000 lumen). For example, Emisar d4 with 4 high cri led has 2350 lumen on turbo but only for less than 30s (https://1lumen.com/18650-reviews/emisar-d4v2/). With another battery maybe it can do 2600 lumen but less time. FW3A is another example with triple led and it can do about 2800 lumen with lower cri xpl hi led: https://1lumen.com/18650-reviews/lumintop-fw3a-blf-tlf/. For these two, they are smaller than your convoy so I imagine them to run for shorter time at turbo than your flashlight. What is most disappointing is the sustain thermal stable output is very low, only 160 lumen with FW3a.
When I say lume x1 or any switching driver will have longer or same runtime at higher brightness, you are right that sustain total power remain the same regardless of turbo, but this sustain total power is LED power + driver loss. For linear driver, I made a comparison with experiment data from Mr toobadorz to compare between K9.3 and E12. I know the comparison is not exactly fair but the math show that switching driver like lume1 is almost 40% more efficient for using total energy in battery to led, and it provide 1.5x to 2x brighter operation in sustain state: https://budgetlightforum.com/t/-/54052/479 .
I think is is ok to compare because both flashlight are about the same size (k9.3 is slightly bigger and heavy). Even if the experiment is not accurate and we half the efficieny improvement, the lume1 driver is still 20% more efficient than linear.
I am hoping loneoceans will have a new idea because he says he wants to build a small and powerful flashlight. Maybe you can post on the thread to ask him about his plan. I am still using loneoceans gxb172 with my convoy for many years but I think I will want to try a new 'e-switch' flashlight to replace it.
But maybe you are looking for slightly bigger flashlight with more runtime and lumen, then I agree that maybe 60W is better because your flashlight will be bigger to run turbo for longer, but maybe more led could be better, like 7led. I am thinking fireflies has new E07 version 2 coming out but is now in some delay because of lunar new year. It use 21700 battery. https://budgetlightforum.com/t/-/64022/382 The k9.3 and E12 are also bright enough for your need but I think it is too big?
1: yeah, 3k lumens is about the most you can expect and while it does drop off that is mostly due to heat which will effect a constant current driver as well. Cell voltage drop plays a role but less so then heat. I am going off personal experience more then anything, I just know that with XP-G3’s I could get around 90 seconds of turbo before heat became an issue and output would remain plenty bright during that time (started around 3k lumens, forgot what it was at the end). During testing running another test on the same cell would show only minorly lower current draw.
An XHP70.2 would indeed give the output I want at 40W easily but the issue with it is lack of optics. I am a hardcore TIR optic fan, pebbled tint mixing TIR optics can make even sub-par LED’s look great. I only use reflectors in large lights or situations where a TIR is just not practical. If someone knows of a ~20mm XHP70 TIR optic I would love to try it out but the smallest I have found was 30mm.
2: No argument on steady state usage being better with a constant current driver. I have been campaigning for a high quality boost driver for years. I just want something that allows me to have my cake and eat it too. A driver that could handle 60W for 90 seconds and then drop down to 40W would be fine for me and should be possible for the components as well if designed right. I am guessing that the X1 could be run higher as well, Loneoceans tends to run his drivers pretty conservative compared to what we normally do around here pushing things to the limit lol.
It doesn’t surprise me that the FW3A can’t run turbo very long, that is part of why I didn’t work on that project, it doesn’t have enough mass to allow high outputs for every long. Note I said if the light is built right is can do longer. My S8 is much longer and heavier then an FW3A, the tradeoff is that is can run turbo for much longer as almost all that mass and length is converted into thermal management. The solid shelf also reduces turbo runtime as it transfers the heat too quickly, using a pill and isolating the body from the LED’s can drastically increase turbo runtime.
That driver test is flawed and doesn’t directly measure the driver efficiency. An FET driver on turbo will actually have nearly 99% efficiency as it is just directly connected to the LED and the driver has virtually no losses. Now if you are comparing PWM modes then yes there will be a difference but not nearly as much as some people think. I did some of my own testing and found the efficiency losses under PWM to be surprisingly low. Less then a high quality switching driver but not as much as you would think in my testing although there are many many possible edge cases and gotyas in both directions. Overall IIRC it was within 10% on average.
All of this really doesn’t matter all that much in reality though, all my testing and experience really taught me is that nit picking the details about drivers and LED’s generally doesn’t matter much in the real world. I spent a lot of time working with and developing constant current drivers but after testing side by side, realized that the old FET driver worked just fine and in some ways better.
PWM FET direct driver generally nets you a much nicer tint then a constant current driver for example. That alone has been enough for me to just stick with FET drivers in most lights that use LED’s with tint shift over the power range (such as the SST-20 I am using now)
I am not hard locked on 60w, more locked on needing 2500-3000 lumens on turbo. I know that this will require around 60W of power in most cases, hence I would like to see a 60w capable driver.
If you look back at Loneoceans threads I have been one of the biggest proponents of them I still am as well. Just waiting for a proper driver to be released to jump in. Knowing LO, I can assume he has a pretty good safety margin built in and I am betting I could bump the power up to a point I would be happy with. Just got to have a driver to try it with lol.
Also have not had a host to put it in until now, the S21 looks like a possible replacement for my EDC. Will just have to see what the pill looks like, if it has enough mass to allow for some good runtimes. Then there is finding a good tint LED and optic combo. I have an optic that I think will work well with an XHP50.2 but have not tested it in the real world yet.
These S21 series are perfect for triples. Either will need a custom spacer to convert to a triple, but the bezel opening won’t block any of the optic unlike the 18650 tube style Convoys. That can equal a lot of lumens OTF just right there!
Does anyone make said adapters?
I would be debating between a triple/quad or an XHP50.2. I guess it would largely depend on what tints are available on the XHP50.2.
I did testing a long time ago by milling out the edge of an S2+ so it did not block any of the optic and I think I saw about a 10% increase in output. I sold that modded light to someone on here a few years back.
Kiriba-ru supplied me with the copper spacer to make my s21a into a triple
Good to hear he is still around, yeah I have gotten basically all my spacers from him.