It depends on what type of cart you are looking at. The shaved ice machine or a snow-cone machine needs some source of electricity. The model of ice shaver we have is also available in a 12 volt version. I believe there are several models of ice shavers and snow-cone machines that will run off a 12 volt car battery.  With the right cooler you can keep ice frozen for hours. This way you can operate a mobile shaved ice / snow-cone stand without needing electric hookups. You could easily adapt any of the Gold Medal carts to hold a 12 v battery and a charger. Plug it in a night and unplug and operate during the day.