State of health estimation of battery pack with passive balancing topology

The diversity and number of devices that operate directly on electricity are continuously increasing with technological advancements. The initiation of electric vehicle production in countries like Turkey has heightened the demand for battery management systems. For the safe use of electric vehicles and other large battery systems, the development of battery management systems is necessary. In this project, a battery management system is designed to determine the health status of lithium-ion batteries. This BMS measures the state of health (SoH) of the lithium-ion battery with internal resistance measurement method, state of charge (SoC) with open circuit voltage measurement method and parameters such as voltage, temperature, current are measured with the necessary sensors and processed in the microprocessor. The results are compared according to safe ranges and functions are performed accordingly. In this way, the battery is both protected and the necessary information about the health status is obtained. The design of the circuit board was made on Proteus. The production was done completely by ourselves and the necessary tests were carried out.