I’m looking at maybe getting a Convoy S2+ with the latest no-pwm driver. The stock led is a SST40, which advertises 1800 lumen at 5amps. How much do I sacrafice in brightness/efficiency if I ask Simon to replace the SST40 with the 219C? I like the CRI and color of the 219C much better, but would like to know how much efficiency I’m losing.
The SST40 will be much brighter than the Nichia 219. I don’t know the exact output of the Nichia at 5A, but the SST40 in the S2+ configuration is pushing 1600 lumens easy before the stepdown with the 5A driver. 1800 lumens is more plausible at 6A (with Simon’s 20mm driver). The tradeoff between high CRI and tint vs raw output is pronounced in this case. Plus, you’re comparing a 5050 size LED to a 3535 size LED. The bigger LED will handle higher outputs better than a smaller one as well. The SST40 is also a very efficient LED and operates at a low forward voltage so it pulls lots of current (and makes a lot of light/heat).
I also don’t think the SST40 has a poor beam profile anyways and the color isn’t bad in a SMO reflector, way better than a XP-L2 or xhp50.2, If you opt for the SST40, get the 5000k one he sells. I really like it. In my opinion, the only high power LEDs that have a better beam is the Samsung LH351D and Luxeon V. If you want high output and a nice beam with high CRI, get a Samsung LH351D 5000K 90 CRI. I love that emitter. At 5A, it easily makes 1500 lumens, but is at the limit of the LED so you need to limit the current with thinner driver wires or a lower output cell.
May I go off the topic a bit. What about Convoy S2+ SST40, 5000k vs. Wurkkos FC11 in terms of tint and efficiency? I have owned a few LH351D lights, but never had FC11, and I notice that the tints of LH351D are not consistent. Some lean towards warm and are less green than the others while some are whiter and more green.
The Wurkkos FC11 is tempting. But 2lumen “firefly” isn’t very low. I’d rather it be sub lumen. The UI also doesn’t allow for going straight to the lowest setting. It does seem a very efficient and good CRI LED, but I’ve never actually held it. I like the side button too, and the USB recharge. UI and low are too much of a deal breaker for me even with all the good parts.
With a regulated driver like the Convoy SST-40 driver, thinner wires or a lower output cell won’t lower the current like they will with a FET driver.
The Samsung LH351D should be ok at 5A. It’s a 3A rated emitter, but Texas Ace tested it as seeing its output peak at around 9A with really good cooling. It’s generally not recommended to get close to the point where output peaks in regular use, especially in a light that won’t have the best thermal performance like the S2+ with its threaded pill, and efficiency will certain suffer. But I bet the LH351D will handle 5A just fine.
The 219C is a little more questionable. It’s rated at 1.8A, and saw a peak output at just shy of 7A in Texas Ace’s test. Probably still ok, but there’s less margin to ensure survival of the LED.
I’m actually planning to order a couple of these new 5A drivers, and one of the uses I have planned is replacing the 7135 based driver in an S2+ that a assembled with a 219C.
I would not run a single 219C with an unregulated FET turbo.
LH351D should be able to handle it with it’s low Vf.
Moonlight mode/0.1% on the Convoy “12-mode” CC driver isn’t very low. The FC11 has a visibly lower min output.
I’d take LH351D over SST-40 in anything but a large light built for sheer output.
I tried single LH351D in BLF A6, on turbo it was getting dangerously blue.
Thanks for the input about the moonlight on the Convoy vs. FC11. Good to know.
By not running the 219C on an unregulated FET turbo - does that apply to the Convoy S2+’s driver on the SST-40? Or was that a comment about iamlucky’s driver replacement plan?
[quote=iamlucky13]
Oh, I didn’t consider that. So maybe it’s not a great idea to ask Simon from Convoy to send me a S2+ SST40 but replace the LED with the 219C? Maybe if I want the 219C, just stick with the original 7135-based driver?
The 219 will work fine with the original 8 x 7135 driver. You’ll get a nice beam and good color at around 3-4 amps without stressing it. The 219C wasn’t designed for really high output like the sst40.
Whoops, either typo or I was getting things confused. Meant to say I wouldn’t run it on the 5A Convoy driver, although setting it to a mode group that maxes out at 50% should be okay. In that case getting it with the 4/6/8x7135 driver would be just as good though.
Here is compare from LedCalc between 3 Leds. Data is from LED datasheets. Current in mA is X axis, lumens are Y axis. LH351D is most efficient LED at all.
Edit with new one graph suggested by river345:
I’m not sure whether the LH351D 96 bin is actually widespread, for 90CRI LH351D Mtn Electronics have P6 for 4000K and S6 for 5000K, the SST-40 70CRI bin is N5. I’m not sure which 70CRI bin is widespread for LH351D.