BYD Co, China's largest rechargeable battery maker, will buy control of the country's sixth-largest mini-car maker for 269.5 million yuan ($US33 million) in preparation for making batteries for electric vehicles, the country's Business Daily Update said. BYD said in a statement it agreed to buy 77 % of Xian Zhen Chuan Automobile Ltd, a State-owned company that makes 800 cc cars under the Flyer brand. The price is a 6.4% premium to Xian Zhen Chuan's net asset value.