^^^ like the Violets.
Welcome to the family Sky King. Glad you are enjoying.
Voltage controls temperature. An alternator (car running) runs 13V + and a car battery in good condition and full charge should be about 12.8. The wall wart is rated at 12V.
Other factors like moving air (drafts in cars, both the heater and A/C) compensate for the higher voltage somewhat and can even lead to lower than optimal temps, but still likely to be in the low vapor zone. Compensate with slower draw speed if you are in cold or windy conditions.
An old weak battery? Probably wouldn't start the car...
Dee-O-Gee.