The invention concerns a method for estimating the state of health (SOH) of an electrochemical element, comprising: initiating a charging or discharging operation of the electrochemical element; measuring values representing deformations of the electrochemical element while the charging or discharging operation is being performed, the deformation values measured forming a deformations image signal according to the quantity of electricity passing through the electrochemical element over time; comparing the deformations image signal and a reference image signal, one or more differences obtained by the comparison characterising an estimation of the ageing of the electrochemical element.