Jesse, 
We have a plug in cooler (Coleman) and like it to supplement the fridge in our van. We bought the 120 volt adapter and use the adapter before we leave to pre cool the items we want to bring, we also use the adapter when ever possible when we are camping or parked at friends or relatives. We use the 12 volt option when we are driving but I do not leave the 12 volt hooked up when we stop unless it is only for a few minutes. I would be concerned about running the battery down. (if you have 2 batteries this would not be as big of a concern) If we are camping at sites with no 120 volt power then we bring a ice box type cooler for drinks etc. 

Hope this helps, 

George 

'85 Westfalia

>> Anyone have a suggestion for a cooler for a Vanagon? My wife and I want
>>a cooler for the Vanagon for food and stuff...anyone have any
>>suggestions of good coolers to buy? What about the the ones that you
>>plug in...any info on these and how they work?