The paper presents a proposal of using additional statistical parameters such as: standard deviation, variance, maximum and minimum increases of the observed value that were determined during measurements of temperature fields created on the surface of the tested electrochemical capacitor. The measurements were carried out using thermographic methods in order to support assessment of the condition of electrochemical capacitor under classic durability tests based on methods of determination of capacity and equivalent series resistance. The possibility of using some statistical parameters in assessment of the electrochemical capacitor quality was illustrated. The applied measurement methodology and the results of research associated with the classic methods of supercapacitors’ assessment are presented. The obtained results indicate that the variability of some statistical parameters of temperature fields can be directly related to changing the values of standard parameters describing electrochemical capacitor, which are capacitance and equivalent series resistance.