Does anyone know if any of the the Inspirion 5379's allow charging by the USB port. I thought one of the two of them could be used when I purchased it.  However if it can I wanted to know if I needed a Special Cable to charge from a USB port into one of the two ports.  Thanks

I'm off on Holiday on Monday and its a longer journey and wanted to keep it charged or running whilst on the Plane to watch a couple of movies.