Basic Driver Questions for Triple Build


I have been a long time flashaholic but have done very little modding. I have some basic understanding of electronics and am pretty handy but there are still some small things I am confused about. I want to do a few triple builds off a Convoy S2+ host, 18350’s probably, Nichia 219C and a version using Samsung high CRI’s, Dragon/H17F/Moonlight driver.

I hope the community here can help me. Here goes!

  1. When a driver lists an output current as 3A is that split across the three emitters, or is it per emitter? I assume per, so in a triple Nichia 219C build, each LED would get 3 amps at 100% right?
  2. Why is 3A the sweet spot for many drivers (ie Moonlight Special, Dr. Jones H17F)? I know that LED’s are more efficient at lower currents but 3A, the 219C gets something like 800 lumens right? Ok, why not 4A for 950 lumens? I realize that more current means more heat but how was it decided that 3A is the sweet spot? 2400 lumens at 3A is plenty for me but I am trying to decide how one decides what the “right” current is. I am mostly asking this question to figure out if I should stack extra 7135’s on the Moonlight driver to get higher output.
  3. I’ve found output charts but are there perhaps runtime charts for different emitters at different outputs? Maybe that is a determining factor related to Question 2. In other words, how long do you want to run a flashlight on high.
  4. Any advice on how to best drive Samsung LH351D’s? They look like they put out more lumens than 219C’s at the same current but also require a higher voltage.

Thanks for your help!

Well, for figuring (1) if you run the LEDs in series you add the voltages of the LEDs but the current remains the same. If you run them in parallel the voltage remains the same but you add up the current of all the LEDs. (2) 3A may not be the “sweet spot” but it is the current widely when manufacturers rate the LED output.