METHOD FOR DETERMINING A STATE OF CHARGE OF AN ELECTRIC ENERGY STORE, ELECTRIC ENERGY STORE, AND DEVICE

The invention relates to a method for determining the state of charge of an electric energy store comprising electric energy store cells and at least one sensor, in which method: in a first method step, operating parameters of the electric energy store are determined; in a second method step, at least one maximum state of charge and at least one minimum state of charge are determined as a temporal integral for each electric energy store cell on the basis of a current (I), a current measuring inaccuracy (ΔI), at least one capacitance, a correction value for the minimum state of charge (formula (IA)) and a correction value for the maximum state of charge (formula (IB)) of the electric energy store cells; the correction value for the minimum state of charge (formula (IA)) is determined by means of a minimum state of charge (formula (IIA)) on the basis of a filtered minimum open-circuit voltage (formula (III)) of the electric energy store; and the correction value for the maximum state of charge (formula (IB)) is determined by means of a maximum state of charge (formula (IIB)) on the basis of a filtered maximum open-circuit voltage (formula (III)) of the electric energy store, wherein a maximum state of charge (SOCmax) of the electric energy store is the maximum of the maximum states of charge (formula (IVA)) of all the electric energy store cells, and a minimum state of charge (SOCmin) of the electric energy store is the minimum of the minimum states of charge (formula (IVB) of all the electric energy store cells.