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.