This will be our second trip in our TM this weekend. The first trip, the refrigerator didn't work, and we knew that before we left so we took food in an ice chest. This time the refrigerator is working. We want to lower the unit late Thursday afternoon and leave early Friday morning. We would like to put our food in the refrigerator before lowering the unit. Can we run it on battery, with the fan going of course, overnight? If not, what??? Any advice would be greatly appreciated.