This video shows a Cool Box with ice and fans that pull the warm external air in over the ice, it then circulates around the box before shooting cold air back out through the three holes at the rear. I am using two AC 220 – 240v 50/60 Hz 1 Phase 15/14 W fans. Most others use 12v fans. I find them too flimsy and not powerful enough for the job at hand.To run these fans on a 12v BATTERY or SOLAR PANEL yet maintain total mobility I needed to convert the 220 – 240v AC to 12v DC.To do this I have used a 300 watt Power Inverter which works perfectly adequately. Incidentally, this particular power inverter has a USB Socket on the side which could come in very handy in isolated situations. This uses a Variable Speed Controller to enable me to control the speed of the fans and also Individually Switched Fans.