Lumintop GT nano on the way

Yes, 10180 Li-Ion cell with the Nano body. I wasn’t aware they came in NiMH. I haven’t used the Nitefox head with the Nano body a whole lot but so far no problems and boy, the little sucker is bright. I’m sure it’s not advisable for extended period use but I’ve used it for 1 to 2 minute periods with no ill effects so far.

A problem with using Li-Ion cells with lights that aren’t recommended for their use is sometimes you’ll lose some of the functions such as strobe, low mode, etc.

Earlier in this thread, forum member "jon_slider" mentioned some NiMH 1/3 sized AAA batteries that are almost the same size as a 10180 Li-Ion battery and that was the first time I had ever heard of this size and do not know anything else about them:

Just got mine. Very cool. It wont replace my larger 18650 based lights but cool nevertheless. My first impression was from the box size. The box is smaller than a pack of cigarettes.

A member posted this on CPF….

“I was excited to see you post this extension for the Nano, so I quickly ordered one and it came last night. I popped a good 10440 cell in it and turned it on. All was well till I kicked it into turbo. A few seconds after being in turbo the light went very purple. I pulled the body off and the battery was not being popped up via the spring at the tail of the body. Not sure if that was the cause of the issue or not.

Now, when I put the 10180 battery in the output is lower and the overall light is purple with a small tan spot in the middle. Seems like it may have been overdriving the LED somehow… bummer. At least this happened on a fairly cheap light, I guess.

Just a warning to others, but I’m sure it’s an anomaly of bad luck for me”

No issues for me….

No Blue issues for me Jon…

When I purchased my Nano from Vinh, there was no mention of a copper board or anything else. When I received it, it definitely had a copper board. Later after visiting his site on CPF, he said he didn’t sell them without a copper board.

There’s been many reports now of the Nano’s LED turning purple when turning on turbo but thankfully I haven’t had any such problem and have used turbo in my example in short bursts without any problems.

Anyway, now I notice that Vinh recommends buying the Nitefox light if you want a 10440 tube. BUT he cautions, use it at your own risk!

It looks like these Nano heads can handle 10440 tubes or not.

thanks Gebe and chooma for the reports

do you use protected, or unprotected 10440?

Got one today and am using Ultratac K18 tube with Efest 350mAh 10440 no problems yet.
Has a decent clip on it that works well with Nano plus has spot for trit.
As a bonus the Lumintop shorty 10180 tube fits and works on the K18 head.
The K18 is currently only $19.99 on Amazon without lithium battery package.

Happy so far!

This is my first experience with Narsil, so I have carefully read the NarsilM v1.3 User Manual included with the GT Nano and the main NarsilM forum thread.

According to the GT Nano manual, the factory default for the "Auto Step Down" setting is "Temperature", but the results from my light's "Driver Temperature Query" are very inaccurate and there does not seem to be any adjustment to correct this.

When I do a triple-click "Battery Status Query" followed by a double-click "Driver Temperature Query" with the light stabilized at 24º C room temperature, the light reports that the driver temperature is 38º C which is 14º too high.

If I continue on by doing a double-click "Firmware Version Query" followed by a 2 second button hold, the light blinks 4 times confirming that I have successfully reset the light to the factory defaults.

After resetting the factory defaults with the light still at ~24º C room temperature, the "Driver Temperature Query" initially reports that the driver temperature is 44º C which is now 20º too high but in a few hours it drifts down to reporting 38º C again.

I have not yet used the "Auto Step Down" configuration mode to select "Temperature" which then turns the light on at 100% brightness while you hold the light to feel it's temperature and then click the button when you feel the desired temperature level that you want to set the thermal limit to. I am not sure how well this will work with a low capacity battery in a small light.


Some issues I wonder about:

1) Does the "Driver Temperature Query" from Narsil lights report the temperature accurately and is there an easy adjustment to correct an inaccurate temperature readout?

2) Is there any way to confirm that the "Auto Step Down" configuration mode is set to "Temperature" or should I just enter this mode and quickly click within 5 seconds which keeps the previous configuration which (since I have not set my light) would be some unknown factory default temperature limit?

3) Is it always recommended to do the "Auto Step Down" mode "Temperature" calibration (where the light runs at 100% brightness until you click) both initially before first using the light and after resetting the factory defaults (since this is supposedly the factory default setting)?

4) How does the light behave thermally if you never do the "Auto Step Down" mode "Temperature" calibration (where the light runs at 100% brightness until you click) since this is supposedly the factory default setting?


I doubt any of this makes much difference when using the GT Nano with the miniature 10180 Li-ion battery but it may be important for thermally protecting the LED when using a larger 10440 Li-ion battery and I am also curious what thermal strategy others use with NarsilM in the larger GT-series and other NarsilM lights.

For anyone who wants to know, an email from Lumintop tells me that only the first batch of Nanos in 2019 had aluminum boards and also that the 10440 tube is still under testing and will be released as soon as available. So that means….absolutely nothing.

thanks for sharing info

I got replies from all 3 email inquiries to lumintoponline.com, lumintoplighting.com and lumintop.com

they all said the copper nano is not yet in stock

I wrote back to ask each of them, whether all 3 sites are part of the Lumintop company, or if any of them are separate private resellers.

Unprotected Efest IMR10440.

I wrote Narsil/NarsilM, but doesn't mean I remember everything

1) --> Temp and voltage calibration are compile time settings - there's no UI to set them, and no way to see what they are set to

2) --> Don't think there's any way to see the current setting. If in doubt, set it the way you want it

3) --> Hhmm. I think so if that's what you want.

4) --> Not sure. Based on the driver design, you cant be sure the temp is accurate, and heat depends on amps, which depends on what the battery can deliver, which is based on how charged the battery is, plus how much resistance there is (springs, wires, etc.). There's no definitive answer here. I'm surprised lights are still being shipped with NarsilM actually. I gave up on it a couple years ago.

Also I don't know what their factory default is. NarsilM can be custom configured with compile time settings, and I don't know what the exact source code is they used. They don't even tell me a light is using my firmware, yet alone ask me to help tweak it for the specific light.

Thanks for the response.

One of the reasons I purchased this light was to experience Narsil and it is definitely a bonus having the historical figures involved contributing to this forum.

I have not changed the factory default thermal limits and the highest temperature my light has reported while repeatedly pushing it to Turbo is 54º C (which is not an accurate reading). I am using the included 10180 Li-ion battery which only lasts a few minutes with multiple low voltage blinking warnings before the final low voltage cutout where the light will not turn on. This highest temperature is 16º C (29º F) above the 38º C (which is also not an accurate reading) that the light reports when at a room temperature of 24º C (75º F); so the actual highest temperature of the light that I have been able to achieve is most likely 24º C + 16º C = 40º C (104º F).

I will monitor the temperature and thermal step down capabilities more carefully once I have a 10440 battery with 4 times the capacity of the 80mAh 10180 battery.

Just keep in mind the performance of the cell. All 10440 cells are not alike. Some have lower resistance than others, but none of them can compare with the better 18650's or 21700's. Also the 10440's increase resistance with age/use, faster than the bigger cells.

Got my Nano today:

  • switch LED is not working (should be RED from the pic), tried to enable it through the config UI but it didn't help. The LED is there and looks like the resistor is there, so not sure how they disabled it. I was expecting it to be factory configured with the LED off, but allowing you to turn it on. Probably a good idea to have it disabled because when NarsilM sleeps, it doesn't do LVP, unlike Anduril, and with such a small capacity cell, not a good idea to keep the LED ON.
  • appears to be pretty decent throw, considering the battery
  • I got a copper MCPCB, and appears to be DTP. I got pointy needle type of leads on my meter, and you can see bump outs of the center pad, so I pocked one of the leads through the top layer and got continuity with the MCPCB base.
  • charging works! Light went green, batt measured 4.16V

Of course I took the driver out, and as expected, it has a 20 pin ATTiny85, no pogo pin I/F, and also the CPU is on the top surface of the bottom PCB so blocked from any type of clip. Dismantling the 2 PCB's looks risky for me to do - easy to get apart but re-assembly would be tricky to align it, and level them perfectly.

Would like Anduril2 in it so could do voltage and temp calibration, and enable the switch LED, since Anduril2 monitors LVP even when asleep.

As many have reported as I did in my post earlier. No biggie as who cares as it’s probably a battery drain anyway but it’s weird that Lumintop would tout it as a nice feature.

Red Led comes on when battery gets weak.

Nice but if it doesn’t work at all?

GT Nano Manual