Modeling and Simulation Evaluation of Current and Temperature Inconsistency in Parallel Connected Lithium-Ion Batteries

Abstract

At a working case, there exists the current and temperature inconsistency in batteries group, especially in parallel connected ones. To investigate influence of the cell properties and thermal boundary condition inconsistency on battery performance, at first a equivalent circuit model (ECM) of individual cell is established to identify parameters of ECM in various temperatures and validated by experimental measurements. Then, the model of parallel connected batteries group is developed to simulate the operations of parallel connected batteries group. The simulation results indicate that, both cell resistance and thermal boundary condition inconsistence have significant influence on currents and temperature imbalance in parallel connected batteries group, thus, decreasing contact thermal resistance between cells not only benefits temperature conformity, but also reduces current imbalance among cells.