Methods for Monitoring the State of Batteries in Automotive Applications

Abstract:
The commercialization of electric and hybrid vehicles leads to an increasing demand for a long life time of their batteries. To achieve this goal, and for safe and reliable operation of the batteries, the current state of the battery is a crucial information. On the one hand, this state comprises the current operating point, e.g. terminal voltage or state of charge, and, on the other hand, the slow varying characteristics (state of health) of the battery, like the capacity or the internal resistance. In this paper, a survey on existing approaches to solve the monitoring task is presented, comprising the full range of currently used cell types in automotive applications. Therefore, the different properties of the existing approaches are pointed out. The main properties of the monitoring tasks in this context are the parameter(s) that can be monitored, the used measurement information, and the complexity. After categorizing the investigated approaches, the methods are discussed, including an assessment in terms of the applicability in automotive applications.