A method for determining at least one characteristic variable for the state of a battery includes: (a) determining the charge throughput of the battery per time step; having, (b) determining a first characteristic figure in order to describe the stratification of the electrolyte concentration in the battery on the basis of a defined initial state for an as-new battery, and of a second characteristic figure in order to describe the stratification of the state of charge in the battery on the basis of a defined initial value for an as-new battery during operation of the battery, in which (c) in each time step, the first characteristic figure and the second characteristic figure are adapted as a function of the charge throughput from the instantaneous state of the battery, and at least one characteristic variable is determined from the first and the second characteristic figure.