Abstract: A video conversion device, containing electronic circuitry for conversion of a High Definition Multimedia Interface (HDMI) signal fed through input terminal to a Serial Digital Interface (SDI) signal which is outputted through output terminals, is connected to a conventional video camera battery pack. The body has four L-shaped slideway formations to receive slides on a battery plate to form a push-on physical connection with the camera. One side of the body is recessed, with four lugs or slide formations complementary to the slideway formations, at the edges of the recess, to be fitted into the slideways formed in the base of the battery pack to the slideway slots in the conversion device, and the battery pack can be quickly fitted to the conversion device via a push-on connection. The battery pack supplies power to the circuitry of the conversion device through terminals which is then supplied to the camera.