I have a NOCO Genius 1 I use Occasionally and I put it on our tractor that I normally run a battery minder on. The tractor is in an unheated garage, temperature this morning was 18°f this morning out there. The float voltage was sitting at 12.91v, which I give the charger an A for effort, however it was far below what it should have been. The charger was indicating it was in maintenance mode. I should mention this tractor battery is under 2 years old and has almost a perfect internal resistance reading. There is no draw what so ever on the battery.
I hooked my Battery minder 2012 up and sure enough it did its thing and I checked it an hour later and it was floating along nicely at 13.95 Volts.
The Battery minders with temperature compensation have the temp sensor outside the device, the NOCO Genius 1 supposedly has temperature compensation and the sensor is inside the device. I can only assume that the heat generated from the transformer inside the device effects the ambient temperature sensor inside the device and there is not correct internal compensation, or the programing of the logic does not continually hold float voltage at the maximum allowable voltage for the corresponding temperature and this is by design and part of the Genius working its magic, or the float voltage simply is not as high as on the battery minder, which doesnt make sense and would create its own issues.
I cannot find any information in the NOCO manual on the charging algorithm like I have found in battery minder or Ctek manuals.
I am going to run a few more experiments and see what we find. The Battery Minders have been my favorite thus far, I have several and they are top notch in my book. I do like that my NOCO 5 has a "repair" mode that runs the voltage up high and gives the battery a nice equalizing charge, which is why I bought that particular one to begin with.