Abstract: A method for monitoring the state of health of at least one contactor in a battery pack, wherein the battery pack comprises at least one battery cell, a first interface line and a second interface line, wherein at least one switchable first contactor is arranged in the first interface line between the interface and the at least one battery cell, and at least one switchable second contactor is arranged in the second interface line between the interface and the at least one battery cell, comprising steps for the measurement of a first differential voltage across the open first contactor and/or the measurement of a second differential voltage across the open second contactor, and the monitoring of the state of health of the first contactor on the basis of the measured first differential voltage and/or determination of the state of health of the second contactor on the basis of the measured second differential voltage.