Byd Co., LTD. (Stock code: 1211.HK), founded in 1995, was listed on the main board of Hong Kong on July 31, 2002. Headquartered in Shenzhen, Guangdong, China, BYD is a high-tech private enterprise with three industrial clusters of IT, automobile and new energy.

Byd has built nine production bases in Guangdong, Beijing, Shaanxi, Shanghai, Tianjin and other places, with a total area of nearly 7 million square meters, and has set up branches or offices in the United States, Europe, Japan, South Korea, India and Taiwan and Hong Kong of China, with a total number of nearly 200,000 employees.

In March 2007. The company spun off its mobile phone components and modules, printed circuit board assembly and other businesses, and applied for listing on the main Board of Hong Kong. On December 20, 2007, the spin-off BYD Electronics (International) Co., Ltd. was listed on the Hong Kong Stock Exchange, raising about RMB 5.9125 billion. A-shares were listed on June 30, 2011.

In April 2016, BYD Shanwei Company obtained the world's largest single order for pure electric bus (4.466 billion yuan). In August, BYD Co was ranked 175th in China's Top 500 Companies 2016.

On September 2, 2018, the Top 500 Companies of China 2018 was released, and BYD ranked 155th.

Qingdao Ruijie Intelligent Instrument Co., Ltd. is located in the advantageous geographical location, beautiful environment of the coastal city of Qingdao, is a collection of research and development, design, production, marketing and technical services in one of the private science and technology enterprises. Focusing on the new energy vehicle industry, the company provides special test power supply, test equipment, automatic test system and test solutions for power lithium batteries, charging piles, vehicle inverters, motor and other components.

Strong technical force, the main R & D personnel have many years of instrument development experience. Since its inception, the company is market-oriented, customer-centric, accurately grasp the market segments in related fields, high starting point, high standard has developed automatic test system, lithium battery test equipment, power measuring instrument, safety test equipment, AC and DC power supply five categories of products, in the stability, reliability, operability and main performance indicators and other aspects of enterprising.

The company's products are mainly used in lithium battery manufacturing, charging pile, electric vehicles and other emerging industries, but also widely used in household appliances, power adapters, motors, power tools, information communication, lamps, electronic transformers, electronic components, low-voltage power distribution and other industries, as well as metering, quality inspection, commodity inspection and other national institutions and research institutes.

Qingdao Ruijie for BYD cars, batteries to provide new energy testing equipment, quality products and services have been recognized by customers.