12V coolers just plain ****.... juice that is. They take up too much room for the amount of internal volume, can only cool so many degrees below ambient temperature... useless (my opinon). We had a Koolatron which drew 3.1A. Would drain the marine battery in about 17 hours.
We switched over to the Coleman Stainless Steel cooler plus another smaller cooler for drinks and we are now happy campers again.
If you have room there are the larger 5-6 day coolers which are apparently amazing with the ice.
12V cooler = warmish beer, sobernish
ice cooler = cold beer,