A series of non‐converging frequency‐dependent Mott–Schottky straight lines can lead to significant errors in the calculation of the device‐related parameters (such as; built‐in‐potential, barrier height, carrier concentration, etc.) for the ZnO‐Bi2O3based varistors. These errors are illustrated using the frequency‐dependent slope of these straight lines. To avoid this problem, a method of obtaining the frequency‐independent Mott‐Schottky response has been devised for these devices. This method employs the well‐known lumped parameter/complex plane analysis technique, and thereby resolves the complexity of the frequency‐dependent Mott–Schottky response. Using this technique, it is possible to characterize the Mott–Schottky behavior of varistor materials without incorporating frequency‐dependent phenomenon in the analysis. These parameters are self‐consistent, and satisfy the basic/classical Mott‐Schottky equation. ©1995 American Institute of Physics.