I like the spacing overall, except for “low” being ~3.5 lm instead of ~8 lm. That can be fixed with a tiny firmware change.
Efficiency should also be pretty decent at the 43 lm and 160 lm modes, with no driver changes.
DrJones H17F driver from Mountain Electronics. Has everything you are seeking in a driver. It’s the most advanced and best clicky switch driver available in my opinion.
Which cell is it?
Ok, should really be strong. To anybody else I would recommend using a clampmeter though, but I’m sure you know everything about the resistance of shunts and wires and take this into account.
Suspicious … :cowboy_hat_face:
Received mine today (Manker E-14); I ordered it from GearBest on the 16th. A little over 14 days seems to be typical for me from GearBest.
It is a nice little light. Mine has no glue on the head which is great as I ordered the extended tube from Bangood so I can use an 18650 for longer run times. I will have to be careful though as it heats up pretty fast. It will double as a handwarmer in the winter.
Just waiting for sunset now.
Bob
Sharpie do you use Clamp meter ?
Dmm ism’t going to measure the current right in many cases , i had the same issue with 3 dmm’s , including a quality one .
Finally received my 18650 tube today, four weeks after receiving the S41! (ordered at the same time)
At 10 Amps you would lose 0.15 volts here, with some unavoidable contact resistance even more.
@sharpie
post a pic of your DMM and leads please
FWIW, one can measure lumens with a cheap lux meter and a white box and a bit of time to assemble and calibrate. It’s usually easier than reliably measuring amps.
Yep, just checked mine (Nichia S41 from the second batch) and am getting 8.5A-9A with an Efest 18350 and 10.5A with a 30Q 18650 (batteries fresh of the charger).
Measurements taken with a quality DMM and short, heavy-gauge, solid-copper leads.
Maybe not the best test equipment, but it has proven to be spot-on with other factory lights/drivers (measures right @ 3.04A with an 8x7135 Qlite, etc.).
while you wrote i was in the mancave...
I don’t have an accurate way to measure amps over about 2 or 3, but if I do a math-based estimation, here’s what I get:
- 1720 OTF lm measured on an Efest 18350 cell
- 1720 / 4 = 430 OTF lm per emitter
- Add ~10% to cover optics losses: 473 emitter lumens
- Check djozz’s 219B measurements
- There’s a data point at about ~473 lm and 2.4 amps
- 2.4A * 4 = 9.6 amps
Or, without the 10% optics boost, it looks like it’d come out at about 8.8 amps.
So, I’d expect a measurement to be somewhere near that. It’s reassuring to hear that others have measured 8.5A to 9.0A with the same light and battery.
It’s not a direct measurement so don’t put much stock into it. However, I’ve found in the past that similar estimations tend to come out very close to reality, thanks to the high-quality data djozz provides.
Edit: I haven’t attempted a measurement at 30 seconds. With this much power in such a small light with a small battery, I doubt a 30-second turbo measurement would mean much. The output curve almost certainly has a steady decline all the way from zero to when the cell runs dry, and it shouldn’t really stabilize anywhere. That’s the nature of direct-drive hot rods, especially with the heat and power limitations of something so small.
Does anyone know of a magnetic ring that fits on these?
For what purpose?
You could put a ring-shaped magnet around it, or maybe try to fit one into the tailcap somewhere, but neither one seems like it’d be very useful for attaching it to metal surfaces.
Magnetic rings are sometimes used for brightness selection, like on the V11R and RRT01 and Darth, but the S41 has no electronics inside to use that as an input mechanism.
One could also add a grip ring, but those typically aren’t magnetic.
I think perhaps I just don’t understand the question.
Something like what is available for the convoys. Just a simple magnet that goes on the tail cap so you can stick the light to things and work with both hands.
I suspect he is looking for a magnetic ring to go on the end so the flashlight can be held by a magnetic surface.
Bob
Ah, that makes sense. Those look pretty nice. 
I’ve never seen one wedged around the button like that before.
It looks like that area is about 18mm outer and 14mm inner on the S41. I haven’t found any of that size online though.
Yeah, I miss having a magnetic tail after having one on my olight s2 baton. I find that I still carry it a lot just because of the magnet even though I have lights that outperform it in every other way.