NB401 is a battery management chip that integrates high-precision battery calculation method applied to the pack side. It supports 2/3/4 string lithium-ion battery or lithium polymer battery management, and has functions such as monitoring, protection, and metering. The chip integrates two 16-bit ADCs for voltage (or temperature) and current, and integrates hardware protection and wake-up functions, supports SMBus communication, intelligent charging management, and multiple encryption authentications, and has ultra-low power consumption, which can meet the needs of most battery protection or metering applications.