Convoy S6 SFT40 3000K 8A buck driver review with beam shots

[Chasinglumens]

Hey fellow torchbearers , just uploaded my video review to YouTube of this killer pocket rocket

My Convoy S6 SFT40 3000K 8A buck review

[captainkirk]

Thanks for the review! I have the 5000k variant and really like it.

[Quadrupel]

SFT40 hi-cri 3000K is rated max 4A… only cold white low-cri have max 8A

[Manulovich (Puh)]

Who doesn’t care? The 3000k version has the same design as the cold version. Moreover, the 4A limitation makes practical sense only for 5000-5700k sft-40, because there is a spread of up to 1500-2000k depending on the power.

LED test / review - Luminus SFT-40 3000/6500 K - warm white thrower LED with good tint and perfect light

LED Test / review EN Luminus Specialty White SFT-40 2023-10-24 The Luminus SFT-40 has been on the market for some time now. Available only in cool white light color at launch, a warm white variant with high color rendering was also available for a short time, which indeed makes this emitter special, as it combines high luminance with good light quality and warm light color at the same time. The cool white SFT-40 was purchased from Mouser in November 2022, while the warm white SFT-4…

[Hoop]

@Manulovich

Who doesn’t care?

Huh? You I guess?

@Manulovich

The 3000k version has the same design as the cold version.

The phosphor is different. The 3000k variant is a 95 CRI LED which has a 4A max rating. I’d choose the 5A driver for the 3000k SFT-40. Running it at 8A uses a lot more power for not much additional output. It’s mostly heat.

@Manulovich

Moreover, the 4A limitation makes practical sense only for 5000-5700k sft-40, because there is a spread of up to 1500-2000k depending on the power.

The 70 CRI variants have no such limitation, they are rated to 8A.

[ebastler (Moritz)]

@Hoop

Running it at 8A uses a lot more power for not much additional output. It’s mostly heat.

SFT-40 3000K 8A vs 5A: 35% higher output for 60% higher power
SFT-40 6500K: 8A vs 5A: 37% higher output for 60% higher power

I would say that is within the margin of error, and definitely deep within sample-to-sample differences. Why is 37% worth it and 35% not?

Nichia 519A are rated to 2.2A, and yet flashlight people are barely running them <5A. So I would say running a SFT-40 WxH that is specced at 4A with 8A is not far fetched. Especially since it shows the identical lumen over current behavior as the WxE/WxS versions that are specced at 8A.

[Manulovich (Puh)]

Maybe we don’t really understand each other. For example, the 519Ar 9080 and r8000 models have the same design, while the power does not rest on different phosphors. As the power increases, the efficiency drops exactly the same in%, and the same thing happens here.

For example, the SFT-40 3000k in the 5A test gives ≈74% of the flux at 8A (1030/1400), and the SFT-40 6500K gives ≈72% (1820-5A versus 2520 at 8A), which is within the margin of error even between LEDs in the same strip. In other words, 8A on the 3000k version is more profitable to use than on 5000k, if only because the color temperature and hue remain the same over the entire range, with the same increase in lumens in%. And in the 5000k version, we get 4500k at low current, 5000k at 4A and 6500k at 8A.

[Hoop]

@ebastler

SFT-40 3000K 8A vs 5A: 35% higher output for 60% higher power
SFT-40 6500K: 8A vs 5A: 37% higher output for 60% higher power

I for some reason thought there was about a 20% difference in output in the case of the 3000k variant. My mistake.

[ebastler (Moritz)]

Might be different behavior between bins/batches… I based my calculation off koef3s tests, but you never know how different bins behave. Esp with Luminus often having Engineering Samples available that might be (significantly) different from the final production LEDs.

[Hoop]

Pretty sure I inverted the Vf and lumens plots when I did the calculation.

[Oli]

I’ve been using the short S6 with the sft40 3000k 5a linear with a 18350 Keep Power 1200mAh 10 amp battery as my primary EDC for over a year now. The amp draw currently at 100% is 5.6a. At 35% it is 2.0a.
I’m going to switch it up and get one with the 8a buck.
I’m going to try the new Keep Power 1600mAh 5 amp that has a pulse rating of 8 amps.

8A Discharge 18350 1600mAh Li-ion Battery UH1835P2

I guess I’m not up to speed on what that driver is doing when we’re not at 100%.
Any thoughts on that battery working for 20 to 40 seconds of 100% power? And any guesses as to what the amp draw will be at 35%? Most of the time when I’m running 100%, I can live with 10-20 second intervals. If I have to I’ll keep running the 10 amp battery but I’d really like the extra capacity.

[zoulas]

How hot does this light get and how quickly does it heat up.

[Oli]

I think that new keeppower 1600 mAh battery might be the same as the vapcell H16. The positive terminals look identical.
I’ll probably get both the 5a buck and 8a. And maybe both of those batteries. Then I’ll be able to test amperage of all three drivers at various battery voltages with three different batteries. With enough S6s in various locations I won’t have to worry about battery capacity.

[Quadrupel]

Yeah,only cowards follow data sheets.

[Oli]

I like data. I very much appreciate that you provided that link earlier in this thread. I have been blissfully unaware for over a year that I’ve been " potentially” exceeding the manufacturers published data by putting 5.6 amps into the spring which is going into the driver and is ending up at the led at an unknown amperage. I have some questions that I can’t find answers to so I’m going to gather some more data on my own. I promise the 8 amp driver will be used ”for off-road use only".
Long live Evel Knievel.

Edit. I appreciate all of the data that has been presented in this thread.