Recent NiMH-battery modeling supported by finite element thermal analysis

The performance of Ni-MH batteries powering hybrid vehicles is mainly influenced by its operating conditions. A sophisticated battery management is necessary to maximize performance as well as life time. So an adequate battery model is required. This contribution deals with the design of such a model. To begin with a common electric circuit model of the battery is used. Variant battery characteristics given by the data sheet have been dressed into analytical expressions which will feed the electric network. Of substantial interest for all network parameters is the knowledge of the battery temperature. With the aid of the finite element method, variant ambient and cooling conditions have been simulated in advance. Therefrom, the temperature behavior could be considered in the model. With the use of a real life driving cycle, wherein the power request as well as the energy recuperation during a specified time period are given, the battery model has been proved.