Comparative Analysis of Cell-to-Cell Voltage and Internal Parameters Variation for the series/parallel battery pack

Abstract

This paper presents the effect of the internal parameter for the number of the parallel of battery packs. Battery packs are consisted of high-power INR-18650 25R cells. Internal parameters are extracted by discharge capacity experiments and open circuit voltage (OCV) - hybrid pulse power characterization (HPPC) experiments, which are electrical characteristics experiments. Internal parameters such as OCV, voltage deviation, temperature and internal parameters are compared according to parallel connection. This paper proposes a series/parallel-equivalent circuit model made by cell extension and compares the actual battery pack model with the extended battery pack model at a cell. A comparison of the actual battery pack and extended cell model shows analysis of changes in the parallel connection of the battery pack correlated with the safety of battery packs.