I bought the Convoy M21A SFT40 (12 groups) and it preforms really well in both throw and output. I prefer the smaller version C8+ for the size and assumed it would preform the same in a slightly smaller form factor.
I bought the Convoy C8+ SFT40 (12 groups) and it doesn't perform as well. It's not bad, but the output is lower. Maybe the M21A has a P4 bin and the C8+ a N3 bin SFT40. I can't explain why the maximum output would be so different.
I don't know if I should risk buying an other C8+ SFT40 and hope for a better bin or if there is something off with my current C8+. I believe both lights use the same reflector and driver.
I am using my Efest 18650 IMR, 20A max continuous discharge. C8+
0180, 2000 on ceiling bounce test
M21A SFT 40, 21700 Shockli 22A max continuous discharge
0250, 2000 on ceiling bounce test.
I used the Efest 18650 in the M21A and it has the same reading of 0250, 2000 on the ceiling bounce test. I don't think the battery is the problem based upon this test.
I tried the 18650 battery in the M21A and get the same result as the 21700 bettery. It's unlikely to be the battery. The M21A shows a higher output from my lux meter. I don't need it to see the output difference.
-Is the difference quite notable as well as measurable?
I think I read somewhere that the 6amp 17mm (c8+) and the 20mm (m21a) are not actually exactly the same output (the 20mm being a little above and the 17mm a little below). I am not 100% sure of this though.
I don’t have any sense of the scale of the difference, but the above could account for it if it’s not too dramatic.-
If your wanting a higher output c8+ the ramping driver is capable of closer to 8 amps I think. Although it has an unusual UI and no thermal protection. I have one and love it, but look into it first if you get one!
Edit: ignore this, see below, they are different drivers. Still true about looking at ramping driver for potential higher output.
Actually, scratch that, the c8+ is listed with only a 5000mA 12 gro UI p driver vs 6000mA for the m21a. They are both 12 groups but have different max outputs.
I will buy the ramping driver option and thank you for your reply.
Yes the output between my C8+ and M21A is noticeable to the eye and the higher lux readings confirm this. The M21A is brighter. I though both the C8+ and M21A was using a 6amp driver? Maybe that is wrong?
I have tried creating an account on 2 image hosing sites; but they are being very slow sending the verification code.
No problem, I thought so to but looked up they are actually rated differently (5 vs 6 amps). Yeah I like the ramping driver but it’s not a normal ramping driver. It really just allows you to preset three custom levels accessed with 1, 2, or 3 half presses directly.
This review found it running at 6amps with a 30q cell.
My knowledge of the effect of different cell and emitter forward voltages on current is a bit limited to comment with too much certainty here, but I am under the impression it definitely runs at a higher current than the 5amp one with any decent cell. I’ve seen measurements between 6 and 8 amps with an sst40. Once Simon’s Convoy store opens again you can order the driver by itself to swap if your happy soldering.
I can order from Simon, that's excellent news and the Samsung 30Q 18650 cells are 15amp continuous discharge. I have the Samsung 30Q cells too.
I can solder, so it shouldn't be a problem. Thank you for all your help and the review of the Convoy C8+ using the Osram KW CULPM1.TG was very helpful.
It didn't turn out well and doesn't compare to the M21A.
I have been trying to source either 7 or 8 amp driver, but it has been difficult to find a suitable driver. I will get one sooner or later and will have it tested at the lab with an intergrating sphere.