Design and Experimental Implementation of Passive Battery Management Systems Using ARM-Based Microprocessors

In this study, a battery management system using passive balancing technique is proposed in order to enable the batteries in the lithium-ion battery pack to be charged in a balanced way. Lithium-ion batteries have higher energy and power density than other battery types. Besides these advantages, it is dangerous due to risks such as explosion and ignition. Considering these effects, lithium-ion batteries need to be protected by specially designed circuits during the charging process. In this context, a passive battery management system that can protect battery groups from overcharging and balances the amount of energy in the battery cells has been introduced. The passive balancing circuit measures the voltage value of each battery cell, compares it with other battery cells in the system, and in case the specified limits are exceeded, the charge current of the battery cell is controlled by operating the switching element in the resistance area. In the designed battery management system, ARM based microcontrollers are used as master and slave. Thanks to the developed system, it is aimed to measure the voltage and temperature values of the batteries and prevent them from being exposed to negative situations such as overcharging and high temperature. Lithium-ion battery group with a capacity of 32 Ah, 20 series and 11 parallel, is used in the battery pack. In the study, analog data have been transferred to the microcontroller using an analog to digital converter unit and multiplexer. Thus, a balanced charge and discharge process of the cells has been realized with passive balancing current. It has been proven with the experimental results that the designed system works successfully