Abstract: A method for detecting defects in an electrochemical device, including obtaining at least one characteristic value dependent on at least one variable received from the electrochemical device and determining at least one defect in said device from the characteristic value obtained. The method comprises a mathematical operation including a wavelet transform, which operation is carried out in order to obtain the characteristic value from the variable received. The invention also relates to a device that carries out one such method, as well as to a corresponding computer program.