Patent ID: 8099180

Claim:
A device for ascertaining at least one of state variables and parameters of a mathematical energy accumulator model, comprising: a processor, including: an arrangement for calculating an error between a measured battery performance quantity and a battery performance quantity calculated by the energy accumulator model, a differentiated component of the error and an integrated component of the error, wherein the mathematical energy accumulator model corresponds to a battery model that describes electrical properties of an energy accumulator based on the at least one of the state variables and parameters, and wherein the energy accumulator model has correction equations to adjust the at least one of the state variables and parameters according to an actual operating performance of the energy accumulator; an arrangement for weighting a proportional component, the differentiated component, and the integrated component using respective weighting factors for each component calculated as functions of an operating point; and an arrangement for feeding back the weighted components into the energy accumulator model for correction of the at least one of the state variables and the parameters, wherein only the differentiated component corrects an internal resistance state variable during battery charging, and wherein the proportional, differentiated, and integrated components correct the internal resistance state variable during battery discharging.