A four-cell direct methanol fuel cell (DMFC) stack with an air-breathing cathode with an active area of 0.48cm(2) for each cell is designed, fabricated and tested. A pure copper sheet 300 mu m thick with innovative perforated flow plates (dendrite type) is fabricated and used for the cathode. For the anode, conventional serpentine flow channels made of pure copper sheets 250 mu m thick are used. An extensive parametric study is conducted to determine the optimum working conditions for the fuel flow rate (anode), methanol solution concentration, channel-to-land ratio and stack temperature. Comparisons are made with conventional serpentine flow channels. In addition, CO2 (water) bubbles in the anode (cathode) channels are visualized, and the results are presented and discussed. It is found that the maximum stack power of the four-cell DMFC stack is up to 40mW/cm(2) with a limiting current density of 335mA/cm(2) at a maximum volumetric and gravimetric power density of 11.16mW/cm(3) and 3.13W/kg, respectively. Copyright (c) 2014 John Wiley & Sons, Ltd.