Testing the new fan in the window, temporary installation. The plan is to put this up in the vents in the peak. I also have a twelve volt temperature sensor that can be set to turn the fan on and off at whatever temp it is set to. On first turning the fan on voltage dropped from 13 down to 12.7 volts. I ran the fan for about a half hour and the battery didn’t drop anymore. At least not on the Harbor Freight charge controller, I wonder how accurate that thing is.
The noise is a bit much but not terrible I think once I get it mounted where I want it things will quiet down a bit.
This is a Heng 12 volt fan from Amazon.
Okeler DC 12V LCD Display Digital Temperature Controller Sensor Thermostat Fahrenheit
12.7 volts is a fully charged battery 12.42 is 80% of charge.