A passive cooler doesn't work on electricity but with pre-cooled cooling elements. This ensures that the cooler can be used anywhere. You can use a cooler with cooling elements when you go to the beach or a barbecue in the park. Please note that the cooling elements also take up space in the cooler, so you can't use the full capacity. The cooler with cooling elements is meant to keep your food and drinks cool, but it can't cool back.