Application of different charging methods for lithium-ion battery packs

The Series and Parallel configuration of batteries combination is the most common pack design for delivering the required energy and capacity for Electric Vehicles. However, this combination is hard configured and inflexible to follow the degradation rate of the cells. This problem can be more evident in Second Life Batteries (SLB), which are found in stationary systems and low-speed vehicles. Therefore, this paper presents a self-re-configurable BMS to control and manage a pack of SLBs with relays that can handle the pack’s configuration. The system was built and tested using six different approaches to calculate the performance and efficiency of the pack. The results suggested that a Series configuration ACSC with relays that enable and disable the cells with upper voltage thresholds is the fastest method for charging SLB efficiently. However, Parallel connection was the technique that could reduce the voltage deviation. Despite that, the six methods are suitable for charging the SLB, and the application will depend on the need.