Abstract
Battery systems as a vital part of the electrical vehicles are facing major difficulties, the most important matter is the cells unbalancing. The cells unbalancing leads to individual cell voltages differ over time, decreasing the battery pack capacity that consequently will fail of the total battery system in the long run. In addition, cell equalization acts an important role on the battery life preserving. Several cell balancing topologies have been proposed for battery pack equalization such as; switched shunt resistors, inductor/transformer base, shuttling capacitor and energy converters. Quite a few researches focused the capacitor base cell balancing. This paper is presents a review, comparisons and develop the capacitor based topologies for balancing battery string. With the aid of MATLAB/Simulink® modeling, the switched capacitor topologies have been proposed including circuits, cells balancing simulation, implementations, balancing speed, complexity and system efficiency, as well as, propose a new control strategy for the single switched capacitor.