High-Precision Distributed Lithium-ion Battery Charging/Discharging Monitoring System

Abstract

With the increasing number of fires caused by the failure of lithium-ion battery systems under extreme working conditions, the safety of lithium-ion battery systems is becoming more of a concern. Although the complicated electrochemical reactions inside the battery cannot be measured directly by various meters, electrical parameters such as voltage and current can be used to estimate the battery’s safety condition. In this paper, the Renesas microcontrollers are used to design a distributed series-battery-pack-based charging/discharging monitoring system with a master control unit and slave control unit. First, the functional framework of the system, the hardware circuit, and the scheme for information interaction are all devised. Battery cell voltages are recorded by the slave control unit, and the master control unit collects the data acquired by all the slave control units through internal communication while collecting total battery pack voltage and current. Second, the software programs of each module are written, and the working principles for programs including the master program, data acquisition program, and communication program are provided. Finally, the experimental platform is built to conduct joint software and hardware debugging experiments. The experimental results show that the calibrated monitoring system could perform functions such as high-precision measurement of electrical parameters of a cell and transmission of communication information, ensuring that there is no blind spot during the operation monitoring of the battery pack.