Table 1 summarizes the steady state

Table 1 summarizes the steady state current and water removal from both the anode and cathode as functions of the load resistance and temperature. All these data are steady states—the fuel cell was operated in excess of 4 h for the conditions tabulated to verify steady state operation. In particular the conditions at 95 and 105 ◦C were tested continuously for over 100 h to verify the steady state operation. The results in Table 1 show that the PEM fuel cell was operated in an autohumidification mode over a wide temperature range (35–105 ◦C), with varying load resistances. All these steady states can be characterized as "ignited" except for operation at 105 ◦C wit h a 15 Ω load resistance, where the fuel cell current was extinguished. The fuel cell did not operate stably at either 35 or 50 ◦C with a low external resistance. At those conditions the relative humidity sensors were pegged at ∼100% RH and the fuel cell current and voltage were erratic. We believe at those conditions liquid water condensed in the fuel cell and caused flooding. At all the other conditions the water vapor pressure in the both the anode and cathode effluents was less than 100% RH, therefore, no liquid water was present at the anode and cathode.