It’s in production and XHP50.3 HI will be available soon
Hello Simon,
I am looking for a M2 compatible forward click switch do you have any?
Also I’d like a single mode (“tactical”) driver (not a 12 group that “may” change group by accident when switch quickly on/off/on/…) That could power 5A for a SST40, SFT40, or osram big flat white : it’s it possible?
Thank you
This sounds great, I’ll have to get some in my store
yeah, looking forward for those 17mm boost driver :)
Hey Simon will you start selling the 12amp driver used in the S21D individually?
I have some S21A i want to turn into quads.
I don’t think you should buy it separately, or at all. Really bad design, without any current regulation.
I also plan to replace it with an 8A, or install a 6A with a resistor modification.
Graph from the S21D topic ->
Looks like the FET driver has better thermal regulation though. Convoy’s other drivers aren’t programed to drop below 35%, this is fine on some lower amp models, but for some they get over 80°C
The 8A buck has no thermal regulation, only a timed stepdown over approx 9 min
Oh, I didn’t know that, thanks. Unfortunately, they all have something flaw.
Simon designs good hosts, but sadly the engineer who designs the electronics for him is not very good.
I would like to see a uncooled runtime graph.
In ZeroAir’s test, you don’t see this warming at all.
But it’s good to know that it was timed and not triggered by temperature.
Any chance of you using the SFP55 3 volt LED in one of your 3x21700 series lights? It does about 18,000 lumens at 150 watts.
Very interesting discussion. The yellow graph that I did below is S21D with 519a without any cooling. If you look at ZeroAir’s actively-cooled graph, the step-down is different from mine. ZeroAir’s Turbo runtime settles at 6 minutes at 1150lm/1750lm= 66% , whereas mine settles at *10 minutes* , at 37% .
Doesn’t this difference in both time and output imply that there is a temp sensor, and it triggers and affects step-down?
ZeroAir Graph (Active Cooling)
My Graph (No Cooling)
Maybe use a fan and you’ll get your answer 
Sorry, this is a different driver than what I was thinking. I thought it was the same as the 8A buck driver in the L21B and other 22mm models
No prob. You have great knowledge of Convoy lights. I actually thought it might be timed response too because my S21D always seemed to settle around 9-10 minutes.
But learned something interesting by looking at that ZeroAir’s active-cooling runtime that Tartarus referred too.
Just had a look at the driver and it looks exactly the same as what’s in the L21B. Maybe Simon changed the firmware for that model? If you look at the Convoy L21B SFT40 review on 1Lumen you can see it behaves differently.
Maybe I’ve been wrong this entire time and it has some kind of thermal regulation if kept below X temp. My 4X18A SBT90.2 drops to 35, but using a fan it then starts to increase in output. It’ll never drop below 35 though.
I’ll run a cooled test on an L21B later tonight
@PiercingTheDarkness - we’re on the “same channel.” I’m thinking the same thing and now also want to do runtime with active cooling!
To add to the data points, unlike S21D which always seems to settle/level out at around 9-10 minutes, my M21B with GT-FC40 runtime curve levels out at 2 minutes, whereas M21B with B35AM settles at 15 min. Both lights have 12-group UI.
BTW, the BAM’s Tmax is the lowest of my Convoy’s, around 46° C at 12 min into the Turbo runtime, then it settles down to 42° C at 30 min once temp regulation kicks in. I’ve learned something more about Convoy temp regulation algorithm from this discussion. Very interesting.
Hi Simon,
Is there going to be an 8 amp xhp70.3 driver for single cell tail switch lights?
I have some good news to add to the data points. I did a Turbo runtime with a cooling fan next to the S21D and it does make a difference. From 100% start, output dips to 46% at 10 minute mark (vs ~37% non cooled), then it actually started rising over next 20 minutes, to 53% at 30 min (non cooled never rose from 37%).
During the run, external temp at the head of flashlight hit a high of 54° C at 4 min, but subsequently cooled down to ~43° C the rest of the time. Non-cooled hit “Hi” on IR gun (meaning above 60° C) within first 5 minutes, and stayed there the rest of the run.
That is interesting, but in actual use it’s most likely still going to be stepping all the way down, unless used somewhere with cooler temps or it’s a windy night.
If the turbo is reset, without cooling, it responds as if on a timer every single reset.
Zeroair’s graph is strange though because if it’s a temp stepdown then how could that be at only 35.8°C unless his sensor is inaccurate. I’ve tested the same models in some of his reviews and even with a fan my recorded temps are much higher
Hi Simon, can i have a convoy M3-C with 519A 2700K 
or any other 26800 lights 
1. Agreed
2. Agreed. I might have an answer; something I haven’t posted yet but basically my S21D hits a high by 3 minutes or so and stays high above 60 C for the next 30 min. That’s why it never recovers to be higher than 37% despite of the presence of temp regulation. As for the clock work leveling between 9 and 10 minutes, I agreed and have no idea why. Maybe the algorithm is: once T=55 C, decreased to x output over next 7 minutes and stays there?
3. Agreed. I have the Rowenta fan on Turbo mode right next to the flashlight. Don’t know how he got 35.8° C.