A Comprehensive Review of Power Electronics Enabled Active Battery Cell Balancing for Smart Energy Management

The lithium-ion battery has gained significant amount of attention in the past decade. It has also become popular commercially as compared to the traditional lead-acid battery resulting in an increase in its usage. Salient features like high terminal voltage, energy density and power density of a single cell have led to these growths. Lithium-ion (Li-ion) batteries, however, have their own limitations. Proper regulation of power during both charging and discharging process is very essential. By not doing so, the life span of the batteries reduces drastically and may also at times lead to undesirable outcomes like fire or explosion. To circumvent these issues, a battery management system (BMS) is employed. The limits of the battery like the operating voltage, continuous charge/discharge currents, temperature, etc. must be observed by the BMS to ensure safe operation of the cells. This article provides a review of the various methodologies employed for balancing of Li-ion cells in a series pack; their advantages, drawbacks, and measures to overcome them followed by a comparison of these cell balancing techniques.