The PLA(People’ s Liberation Army) 7431 factory , The Storage Battery Branch of Guangzhou Yunshan Automobile Factory,is a state-owned military enterprise belonging to the Equipment Department of Guangzhou Military Command .It covers an area of 200000㎡and is located in Guangzhou City ,Guangdong Province ,the forefront of china’s opening-up and reform . It is a second-rate state-own enterprise and a first-rate military enterise.