This Work is devoted to research and development of vehicle traction batteries and their management systems. As the battery technology is reaching maturity, personal mobility vehicles are becoming more popular. Within this Work, three battery systems have been developed: two for personal mobility vehicles and one for stationary energy storage. To achieve the set goals, existing vehicle battery packs were analyzed as well as the lithiumion technology itself. Research of battery cell balancing scientific literature was carried out and a novel three group classification has been proposed. Two of the reviewed balancing methods were selected for further analysis, prototype design and experimental verification. The two methods were: switched resistor balancing method and multi secondary winding transformer method. After successful initial testing, both methods were combined in one new mixed twolayer balancing topology, which is capable to improve balancing performance of reference switched resistor balancing topology under favorable conditions. The developed balancing prototypes have been implemented in lithium-ion batteries both for research project purposes and for educational processes.