I have a rather unique problem I hope you guys can help me with.
I put together an S2+ shorty with a 660 nm XP-E and Nanjg AK-47 1 amp driver. I’ve knocked off 2 7135’s leaving me with 350 ma. The problem is it’s still too bright!
Is there a way to reduce to 175ma with a resistor perhaps? Any other ideas?
What about modes?
It’s default AK-47 firmware with 3/5 modes. Low mode (I’m assuming 5?) is about right but 100 is way too bright. It’s for a co-worker and he keeps cycling the modes by mistake. I figured if I could cut the current in half then lock it down to 10, 100 it wouldn’t matter so much if the modes were cycled.
Just to give a little context, I work on a small ship and do a fair amount of night sailing. We’ve been painting ordinary penlights with red nail polish to read our analog gauges but they are too bright under very dark conditions so I built this light as a replacement.
Firmware is changeable, you would probably want a light without memory which would always start in a moon mode.
You can either flash the new firmware yourself or buy a replacement driver with custom firmware.
Of course you could build a very simple flashlight with a resistor but you would loose higher modes and batteryvoltagemonitoring.
Just google led resistor calculator and try it.
I plan on learning programming/flashing next winter when I have more time. Thanks, I’ll google tonight to see what I can find. Can I put a resistor on one of the led wires?
A resistor would lower the output of all of your modes, but wouldn’t keep the driver from cycling through them. It will also reduce your efficiency. You’d be better off with a firmware that gives you the modes you want.
I never tried it but theoretical you solder a resistor between led and driver. It doesn’t matter which wire just desolder a wire somewhere and put a resistor with the correct value in it.
I just used this: http://led.linear1.org/1led.wiz
With 3.9V for the battery and 3V for the LED and 100mA, the result is 10ohm and a normal 1/4W would work.
Just play a bit with the numbers so that you can buy some small value resistors and then try if it gives the result you want.
I’m looking to reduce output on all modes actually and if I cut the current in half then shorting star 4 should give me 2 modes(?) at the reduced output. I just find that 100% at 350 ma is too bright. It lights up the whole wheelhouse.
Thank you Werner, I’m going to get some 1/4 watt resistors and try it out.
If runtime is not a problem, I think picking up a filter would be an easier solution to your problem.
Something like this should fit: [Fenix diffuser]
or use this: [neutral density sheet]
You’ll need to cut the sheet to fit. Sorry, I couldn’t find any neutral density lenses that would sit well inside the flashlight (~20mm) or inside the Fenix Diffuser (~24.1mm).
The neutral density sheets come in a variety of different choices. Pick the one that best suits your need.
You might also consider using the Fenix diffuser and the ND sheet in combination with each other.
Runtime is no issue. We use the light about 15 minutes total on each cruise. I like the diffuser idea, thanks for that. I have lots of stock glass 20mm lenses so I’m going to try to buff one to create the same effect.
You guys are great. Thanks a heap everyone! 
Sounds just about perfect for a single AA alkaline or eneloop host with a 15mm version of the nanjg 110. Bump up the sense resistor to lower output current from stock 700-800mA down to whatever you want. No modes just dim red light on cheap cells.
That sounds perfect for lights for the rest of the fleet. AA is a good thing for these guys so I don’t need to worry about charging. I just need to source out the host and driver. So far all my hosts and drivers are from Mountain and Simon’s shop on aliexpress. I guess I need to broaden my scope a little. Thank you.
If you search on eBay fo cree xpe q5 led you’ll see a bunch of very cheap single AA lights in the $2 range in black and gold. The hosts are of indifferent quality but they have the 15mm version of the nanjg 110 driver and the xpe led. Here’s what the driver looks like from one I opened up. 
The sense resistor is labeled R270(.27Ohm) and stock are supposed to put out ~550mA on a single cell and 700 mA on two so I’d stick with one cell and a .8 ohm resistor should give around 180 mA. Kaidomain has them in bulk for $2.50 each for ten if you don’t want the cheap host. The switches and connectivity in them are crap but what the heck.
While googling around what Rufusbduck suggested I found this (shudder). Who in their right mind….?
10 ohm 1/2 watt resistor inline on the LED leads will reduce the amps. (i have did that mod with several small lanterns)
Thank you Den, I will try that tomorrow. Btw, I don’t know how close to the border you are but did you see this post I made earlier?
I just replied to it 