<p> In recent years, the world has witnessed rapid development of technologies aimed at creating sustainable and environmentally friendly energy sources. One of the most important steps in this direction is the large-scale production of transportation means, including electric vehicles. Today, electric vehicles are becoming increasingly widespread. Uneven charging and discharging of battery cells negatively affects battery performance, increases charging and discharging time, and can shorten battery life. The subject of the study is the behavior of lithium-ion batteries during operation. The aim of the research is to develop a mathematical <br /> model of a lithium-ion battery balancing system based on comparing the effectiveness of active and passive balancing methods. The study includes theoretical and practical aspects such as design, testing, and implementation. The article provides an analysis of existing balancing techniques — a key component of battery <br /> management systems. The methods under consideration are classified into passive and active types according to their operating principles, which made it possible to determine their technical features, advantages, and limitations. The choice of a balancing method depends on the application area and requirements for accuracy, <br /> speed, and energy efficiency. Passive strategies are suitable for consumer devices, whereas active methods are recommended for critical systems such as electric vehicles. Experimental studies confirmed the practical efficiency and reliability of the active balancing system based on an inductive converter under real operating <br /> conditions of a lithium-ion battery module (charging, discharging, high current, high temperature). This system successfully eliminates voltage imbalance, increases usable capacity, extends battery life, and ensures safety.</p>