BYD, the world's largest maker of cell-phone batteries, has been expanding into the auto business with electric cars. In Detroit for the first time, the Chinese company showed off its F6DM, a hybrid-vehicle powered by the company's own lithium-ion batteries. The first BYD hybrids are scheduled to go on sale in China later the year. The entire hybrid system, including the engine controller, generator and electric motor was designed by BYD's own engineers.