When I leave mine set on about 3, it will run all night and the batteries will still start the motor in the morning. I don't know if it is the exact same model. If you switch the battery switch so that you are only running the refrig off of one battery, you can then switch to the other for starting. I have also found that the temperature holds well in the refrig if you feel more comfortable turning it off for the night. If you turn it off just before going to sleep--don't open the door all night--and turn it back on in the morning, the contents stay cold. When I am out for an extended period I use a Honda 2000 generator. I can use it to top off the batteries if, for instance, I don't feel like running the motor after having the refrig on all night. Hope this helps...