First light build, Convoy S2+ with Red LED?

I can’t find a good flashlight with a red beam that I like, so I was thinking of making one. This would be my first time modding a light. I am thinking about using the Convoy S2+ for the host. I have no idea what LED I should use or where to get it. Can anyone tell me how they would go about this project, and where I might find the right LED/resources? Thanks.

Hello :slight_smile:
I think Mountain Electronics sells a couple of red LEDs on MCPCB that could fit in a convoy host

Thanks! That’s super helpful. Do you think I will need to find a new driver board for it as well, or just pop out/desolder the old MCPCB and replace with a new one?

My knowledge ends here sorry, wait until some other people reply.

So Djozz tested the red first gen. XP-E up to 3.2 amps, but the butter zone for that particular 620nm red emitter was 2.2 amps. A linear driver with six 7135 regulators should be a good fit for a conservative single emitter setup. This driver from kaidomain should fit in the S2+ host. You also want to make sure you buy a 16mm diameter MCPCB so that it fits in the host. Keep in mind, the red emitters from MTN are the 660nm “deep red.” They look a bit richer then your typical red. Here also on kaidomain, you can get your hands on a 620nm red on a 16mm board if you desire a more typical seen red.

mtn elec has a regular red, too, not just the 660 nm. I used one in a bike taillight, with a Convoy 4x7135 driver (custom firmware based on Biscotti)

I think mtn has everything you would need to build one, even the host. You can use one of his 17mm 8 amc7135’s driver and remove amc7135’s to reach your desired reduced current.

Funny, before seeing the last few comments I had just placed an order with mtn. Picked up a red S2+ host, 20mm 3 LED MCPCB with all XP-E photo red and a 17mm DrJones H17Fx Driver w/ lucidrv2 - 7135 + FET along with the spacer and a couple lenses to try out. Can anyone tell me if thats a sensible parts list? I am slightly worried that the driver will be too powerful, because at 100% it is direct drive and Cree says the XP-E photo red max drive current is 1A. I don’t understand electronics that well, but if 3 identical LEDs are wired in parallel, at 3A each LED would get 1A. Is that right?

Parallel wiring can be kind of tricky, speaking as one who has a couple of times mangled the soldering needed.

The LEDs come pre-soldered to the board so hopefully that won’t be a problem. I’m not the best at soldering but I will do fine if I just need to connect a couple wires to reasonably sized pads.

The XP-E2 red is, I think, a little better than the XP-E red. But I can’t tell much difference, I’ve used both in Convoy S2+ lights happily.

I went with the “photo red” which is >650nm. I think that will be better for preserving night vision. This is the board and LED choices they have (pre-soldered): (3) Color / White LEDs on 20mm Sinkpad 3XP MCPCB - Mix and Match

Voltage drop of red LEDs is lots lower than that of white LEDs, so use a current-controlled buck driver for best results.

7135s will cook. FETs would almost instantly destroy the LED.

Or as crappy as it might sound, use a crappy driver with the appropriate resistance to limit current.

  • Photo Red 660nm XP-E2 from Sofrin or 660nm SST-20 Deep Red from Hank (intl-outdoor) if you want real red and not orange-rosy red
  • 30dg or 40dg TIR in 3535 size for universal beam patter, OP is way to narrow in buildings (tunnel vision, not nice) and 60dg is too wide (a wall of darkness in front of you in the woods)
  • 5 or 6 AMC Biscotti driver from Simon so the “moonlight” mode is fairly low and the led is not overdriven

A dual channel driver would be ideal but these are hard to get.

So… I’ve already ordered the Photo red XP-E LEDs because they were available presoldered to a board that will fit the S2+. Now I am trying to figure out what driver will not burn it out. Someone said they used this driver with the 3*XP-E2 Red and it worked, can anyone tell me if it will burn out my LEDs? QLITE REV.A 7135*8 3.04A LED DRIVER (QLITE REV.A 7135*8 3.04A LED DRIVER - 17mm)

So that driver (max 3.04A) driving 3 LEDs in parallel is one option I found. I really like the firmware available for it. A little bummed it only goes to 3 amps, I figured with 3 emitters they could handle more than that, but maybe red LEDs are different. My idea is to build the nicest light I can, with good modes and as high lumen as possible on hi. Not really into a single mode light. The other requirement is that it does not put out any light less than 650nm, or as little as possible. That makes it a true red that will have almost no impact on night vision. This is also the first time I’ve built a light and my only electronics experience in the past was soldering though hole components on a couple of headphone amplifier kits.

8x7135 is definitely going to have an effect on night vision :slight_smile:

You can find higher powered drivers (I love the 5A 12 mode convoy driver) but an S2+ is going to get too hot to hold comfortably after a
few minutes even at 3A. If you want high sustainable lumens go with a lower power driver or a bigger host.

You got me. I’ll admit, I want to make the brightest light I can for no real reason :smiley: . I will probably run it at lower current 99% of the time. I just want to make sure I can run it at 100% without immediate catastrophic failure.

KD sells some flashlights:

with S2 body style here


with C8 body style here

Jaxman E2L with triple red LED here

Those are good suggestions, but I am not seeing any of them that have the specific type of red emitters I want (>650nm). So far the only factory light I’ve seen with the exact emitter I want is a Sofrin AAA single emitter light. here

Yes curious wich temperature hold these linear 7135’s for burn all voltage excess
I would like to know how these xpe deep red can work good on a boost AA driver like a sk68 or sp10s