A method for determining the wear to a storage battery by monitoring the state of charge of the storage battery includes identifying a plurality of deep discharge events when a state of charge value for the storage battery is less than a minimum state of charge value specified for the storage battery. The method also includes determining the duration of the plurality of deep discharge events and determining a wear variable which characterizes the wear as a function of the total number and the total duration of the plurality of deep discharge events. The wear variable increases as the total number and the total duration of the deep discharge events increases. A monitoring device comprising a measurement unit and an evaluation unit that is configured to use the method may be provided. A computer program having computer program means designed to carry out the method may also be provided.