You are correct. Keep in mind, these trailer reefer's are lame at best. During the day I keep ours at maximum cooling and dial it back one setting before retiring for the night. Try not to open the refer\freezer door too much either. It gets warm real quick. Summer camping, I keep a large cooler outside and have no problems buying 2 bags of ice daily just to keep soda's, beer, condiments and other items you normally keep going into the fridge for in there. Then the refer has a better chance of keeping stuff like ice cream frozen and not a puddle of goo.