The present invention is notably directed to methods for estimating a degradation of an electronically controlled electro-mechanical switch. The methods comprise determining a change of state of the contactor. They also comprise, computing, for each determined change of state, a wear increment WI of the contactor by: identifying a wear coefficient using a mapping between a last measured current through the contactor and a current range associated with a given wear coefficient; computing the actual wear WN of the contactor by adding the computed wear increment WI to a former known wear WI−1 of the contactor.