Current Variation in Parallelized Energy Storage Systems

An electric vehicle battery pack may employ cells connected electrically in parallel to meet energy and power requirements. For the battery management system, cells connected in parallel are often treated as a single larger component. However, research has identified that the state of charge and cell current may not be equal due to differences in capacity, impedance and cell temperature. In this paper, the authors develop a parallel cell model validated against experimental data. The model is used to evaluate cell energy variation and the impact this can have on the design of highly parallelized battery systems.