The electrical response of the direct methanol fuel cell, based on solid polymer electrolyte, to variable load is reported. The dynamic power response of the direct methanol fuel cell is of importance particularly when the cell is used for transportation applications. The study reports the dynamic characteristics of a small-scale cell (active area 9 cm(2)), a large-scale cell (active area 272 cm(2)), and a three-cell stack. The effect of operating conditions (i.e., flow rate, cathode pressure and solution concentration) on the voltage response is described and the effect of a change of scale is discussed.