I bought an S70S because they were on sale for a very good price lately and I wanted to see their construction. I decided to post my mods as I haven’t really seen any other threads on modding this light.
First off, I really did not like the stock User Interface. I ordered a 30mm FET driver designed for the L6 from Mountain Electronics using the D4 UI or RampingIOS. Unfortunately the ramping is not so smooth due to using a single FET on a 2S driver. I’m thinking Richard doesn’t have time to modify the code to make the ramping perfect. It’s fine, though.
I trimmed the edge with a Dremel to make it 29mm. I’ve heard some S70S use a 27mm driver so verify which you need before ordering.
Here are the factory driver wires.
Make sure to label one of the white wires as there are 2 of them.
Here is where to attach the wires to the MTN driver.
In order to have a custom lighted switch I had to get creative. There are no outputs for a switch light on the MTN driver. I had to run switch light power directly from the positive side of the mcpcb. You can see the extra red wire here.
Don’t try running it from the main led black wire on the driver. It will cause a small current flow and the main led will glow when off.
Here is the stock switch pcb.
I removed the stock leds and used my own blue led on the 1000 ohm circuit where the green led used to be. This was too bright and had too much drain. I later went back and swapped it to the 5000 ohm circuit. Even 5000 ohms is too bright. I’m going to try a 24,000 ohm led soon to reduce parasitic drain even more. I also rotated the switch pcb so the light looks better.
Here is the final look.
Here are the notes I made along with performance data. I forgot to measure stock candela. After the driver swap I measure 125kcd or 707 meters.
Parasitic drain on the stock light is very high at 4.43 millamps. I think this is due to the particular green LED used and the small 1000 ohm resistor. When I installed the new driver I wired up the stock green led as a switch light. I know the MTN driver only draws 0.078 milliamps once the mcu goes to sleep. The green led drew 6.45 milliamps! I swapped to blue led and a 5000 ohm resistor and got the drain to 1.2 milliamp. I will try a 24k ohm resistor next to see if I can get the drain down to below 0.3 milliamp. (EDIT: I swapped to 24k ohm and get a 0.320 millamp drain. This still seems high considering the BLF Q8 can get 0.123 milliamps and that’s with 2 leds.)
The factory rating of 3800 lumen turned out to be a pretty low 2900 to 3000 lumen stock. The FET driver definitely wakes up the stock xhp70 to about 5,000 lumen.
I get a definite donut hole pattern with this light which is something I didn’t see with the stock Convoy L6. You would think the heavy OP reflector would blend it better. The stock centering ring height is 0.8mm. I tried shimming it up to 1mm, then 1.4mm with no real change. No biggie.