A method for detecting a bad contact of a charging cable comprises: measuring a cooling fluid temperature of a cooling fluid flowing through the charging cable; measuring a connector base temperature of a connector base of the charging cable, which connector base carries an electrical contact element of the charging cable; estimating a contact temperature of the electrical contact element by determining the contact temperature from a difference of the connector base temperature and the cooling fluid temperature; and deciding presence of a bad contact, when the estimated contact temperature is higher than a threshold temperature.