Physics Based Model of a Valve Regulated Lead Acid Battery and an Equivalent Circuit

Abstract

Lead (Pb)acid batteries are a lowcost power source for applications ranging from hybrid and electric vehicles (HEVs) to largescale energy storage. Efficient simulation, design, and management systems require the development of low order but accurate models. In this paper we develop a reducedorder Pbacid battery model from first principles using linearization and the Ritz discretization method. The model, even with a loworder discretization, accurately predicts the voltage response to a dynamic pulse current input and outputs spatially distributed variables of interest. A dynamic averaged model is developed from the Ritz model and realized by an equivalent circuit. The circuit resistances and capacitances depend on electrochemical parameters, linking the equivalent circuit model to the underlying electrochemistry of the first principles model.