Power battery requires high-power charging and discharging performance, which is mainly used in electric bicycle, electric tricycle, low-speed electric vehicle and other fields. The market demand shows a steady growth trend. The power battery market is divided into primary market and secondary market. The primary market is the new car market and the secondary market is the maintenance market. At present, the lead-acid battery replacement cycle is about 2 years. The sales volume of lead-acid batteries for electric bicycles in China will grow steadily at a compound annual growth rate of 5.4% from 2016 to 2021. The electric tricycle has the dual functions of transportation and carrying goods. It is widely popular in rural areas, second and third tier cities. The booming express industry basically relies on the electric tricycle to deliver the last kilometer. On October 26, 2015, the State Council of China issued several opinions on promoting the development of express industry. According to the opinion, in 2020, China will basically realize express delivery with outlets in villages and villages, and the annual business volume of express delivery will reach 50 billion pieces. National standards for special electric tricycles for express delivery, as well as production, use and management regulations, will be studied and promulgated. The rapid development of China's express delivery industry and the acceleration of urbanization are bound to promote the explosive growth of electric tricycle market. In 2015, China sold 15 million electric tricycles, a year-on-year increase of about 30%. It is estimated that by 2020, the number of electric tricycles in China will be close to 100 million. With the healthy development of industry standardization, lead-acid batteries for low-speed electric vehicles have become a new growth point. At present, the low-speed electric vehicles using lead-acid batteries are mainly concentrated in Shandong, Henan and other provinces. Since 2014, local industry specifications have been issued one after another, and the industry standardization has been improved. For example, on June 12, 2014, Shandong Province issued "Shandong Automobile Industry Standard (small pure electric vehicle)", and "Shandong small electric vehicle production enterprise access conditions", March 2014 In June, Luoyang City, Henan Province issued the Interim Measures for the production and management of low speed four wheel electric vehicles in Luoyang City. In 2015, Shandong Province produced 347000 small electric vehicles, a year-on-year increase of about 53.7%, and the output increased by more than 50% for three consecutive years. Shandong province put forward the plan goal of producing 1 million micro electric vehicles annually by 2020.