New Temperature-Compensated Multi-Step Constant-Current Charging Method for Reliable Operation of Battery Energy Storage Systems

Battery lifetime represents a significant concern for the techno-economical operation of several applications based on energy storage. Moreover, the charging method is considered as one of the main critical elements in defining and influencing the operating lifetime of batteries. Several charging techniques have been addressed in the literature, however almost all of them are suffering from lack of temperature feedback in order to maintain battery lifetime. This paper presents a new high-reliable charging method for battery energy storage systems (ESSs). The proposed temperature compensated multi-step constant current (TC-MSCC) method is developed based upon the modified (MSCC) charging method. It enhances the operating lifetime of batteries by employing a feedback from the battery temperature to control the duration and starting time of each charging current step. Compared with the traditional charging methods addressed in the literature, the proposed TC-MSCC method achieves faster charging than the conventional constant current (CC) and the constant-current constant-voltage (CC-CV) methods. Moreover, the proposed TC-MSCC method possesses longer operating battery lifetime with reduced thermal stresses compared to the traditional MSCC methods. The proposed charging method is verified by simulation and experimental results using 9 Ah lead-acid battery. However, the new proposed TC-MSCC method is generalized and can be applied to various types of batteries. The detailed performance comparisons and results show the superiority of the proposed methods over the most widespread charging methods in the literature.