2004 BMW 530i electrical issue

My 04 BMW 530i suddenly wouldn't hold a charge on the battery. I had the battery fully charged, and checked. The parts store said it was good. I began driving the next day, and the interior began to get a little smoke. The smoke seemed to be coming from the dash. The in dash display, radio, and cd player went out. As I continued on the gauges flipped off and on but finally stayed on (gauges), but the display, and audio never came back on. I got the vehicle back home and the battery died again.