FASTTECH host driver retaining ring question

Ok, I don’t have many 18650 lights, but depending on how I take to my recent order of batteries, I’ll be building some lights to accommodate my growing interest in that form factor. I favor smaller, 16340 lights….habit I guess.

Anyway, I’ve been looking at some of the lights that have the driver retaining rings (FASTTECH has the Convoy hosts and CNQ has at least 1). It just seems better than soldering them in, maybe I’m wrong. Regardless, I like the idea and want to try it out.

Here’s my problem, from the limited understanding of the sizing on these pills and rings, I think the rings only work if you use a 16mm driver. If you use the “normal” 17mm, you just solder as normal. This is what I’d like to confirm.

Ok, I took a look at another thread I’d read before. It looks like you can use the 17mm driver, but can’t use one with components on the battery side….(ie. the KD V2 7135’s I was going to get)

So…. If you have a convoy host, and can chime in, that would be GREAT!

I also like the KD 8x7135 V2 LED 3040mA driver. I like the KD driver with 5mA low for my EDC Ultrafire 602C DIY LED flashlight host I got from Fasttech for $5. I’m using a Efest IMR 16340 to put out 3.8 amps because I added two 7135s on the battery side of the driver. This runs a XP-G2 R5 3C on a copper SinkPAD. This may be too hot for some people. Very hot in 3 minutes. Battery lasts about 10 minutes worth of bursts on high. 3 amps may be better in this small host. Don’t try to run this many amps to a XP-G LED on aluminum. You can get LED’s on copper Noctigon MCPCB that have a direct thermal path at I have added three 7135s to a Convoy S4 on the battery side of the KD 8x7135 V2 LED 3040mA driver with the 50 mA low. This puts out 4.2 amps to a XM-L2 T6 3C on a SinkPAD. I got a Convoy C8 from Fasttech that came with a Nanjg 105c. It’s very similar to the KD driver with 7135 on both sides. I will stack some 7135s on this driver on the battery side but will need to file the retaining ring to clear the 7135s. I may use the brass pill for a C8 from Kaidomain so I can solder in the driver to handle the heat and won’t have to file or grind a retaining ring. You can stack 7135s on the inside of the driver also but then you can’t quickly see how many you added latter with out unsoldering the driver.

Oops, the KD pill for C8 has different threads. I may have to cut new threads in the KD pill because it can use a 20mm Noctigon MCPCB for better heat management and can be screwed down. The KD pill even comes with screws.

I have used the Nanjg 105c in the S3, & S4 Convoy host with no problem. In the Convoy M2 host FT SKU 1138202 can come in handy, so grab some of them when you order your drivers.

You can still us the KD V2 driver without the driver retaining ring. You'll have to solder the ground of the driver to the heatsink. It could get a little tricky as you'll have to have a solder gun hot enough to heat up the heatsink to create the bond. My little trick is to disassemble the components and tin the heatsink beforehand with solder. Then you bridge the driver to the tinned heatsink. Works everytime.

thanks! never thought of pre tinning the heatsink. great idea!

+1, thanks for the idea.