Coleman's RoadTrip 16 qt. Thermoelectric Cooler is an essential patio, campsite and road-trip beverage keeper--and it doesn't require a trip to the gas station twice a day for a sack of ice.
The unit comes with two lids, one for regular toting around in powerless situations, the other with a built in refrigeration-type thingy that plugs into a car's cigarette lighter (or A/C adapter for home or amenity-campsite use).
One problem: it only holds 20 cans, so you will have to drink four beverages from your 24-can flat forthwith.