Humidity and cell pressure were measured at the inlet for both electrodes. Cell resistances as a function of current density (i.e., the sum of the proton-conduction resistance in the membrane and the various electronic resistances, bulk and contact resistances) were determined using Hioki at 1 kHz. Multiple-path serpentine flow-fields (two and three parallel channels for the anode and cathode, respectively) machined into sealed graphite blocks were used for testing.