EPS power supply, also known as fire emergency power supply, with the full name of Emergency Power Supply, is an emergency power supply adopted in important buildings nowadays for power guarantee and fire safety. It is mainly composed of input and output units, charging modules, battery packs, inverters, monitors, output switching devices and other components. It is widely used in chemical plants, petroleum industry, hospitals, schools, shopping malls, stadiums, convention and exhibition centers, financial systems, subways, high-speed railway stations, tunnels, expressways and other places.