A simulation study on parameter variation effects in battery packs for electric vehicles

As one single cell cannot meet power and driving range requirement in an electric vehicle, This is needed to construct battery packs with hundreds of single cells connected in parallel and series. The most important difference between a single cell and a battery pack is cell variation. Not only does cell variation effects pack energy density and power density, but also it causes early fade of battery packs and even results in safety issues. This paper first introduces the characteristic and description of cell variation in battery packs and establishes a pack model with 96 cells connected in series. Subsequently, the influence parameters of cell variation are studied. The results show that temperature and coulombic efficiency are the major parameters which effect cell variation and the results also imply that dissipative cell equalization is sufficient for battery equalization. (C) 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.