The disclosure relates to a method for monitoring the state of a battery. In the process, the internal temperature of the battery during a charging process is determined in defined intervals at different time points, and an evaluation unit continuously determines a temperature gradient at least from the temperature values. At least one limit value for the temperature gradient is stored in the evaluation unit, and the evaluation unit generates a signal when the temperature gradient which is determined by the evaluation unit reaches this limit value. When this signal from the evaluation unit is present, the charging voltage of the battery is driven such that there is no battery current, while the internal temperature of the battery is further periodically detected, and the evaluation unit generates an alarm signal when the temperature has fallen after suppression of the battery current.