Hybrid fuel cell for pulse power applications

A hybrid fuel cell demonstrated pulse power capability. It successfully ran a pulse power load simulation synonymous with electronics and communications equipment. The hybrid consisted of a 25 W proton exchange membrane fuel cell (PEMFC) stack in parallel with a 70 farad capacitor assembly. A cyclic regime of 18.0 W for 2 minutes followed by 2.5 W for 18 minutes was chosen as the basic test regime. The operating potential cut-off voltage for pass/failure was set to 3.0 V. At room temperature (23-25/spl deg/C), the PEMFC alone could not successfully power the baseline regime previously described. The PEMFC operating potential dropped below 3.0 V within 10 seconds. The hybrid continuously powered the cyclic regime for 25 hours. The hybrid's operating potential never reached the voltage cut-off, even during the high load of 18.0 W. The tests were aborted after 25 hours of operation with no signs of output degradation, suggesting that continuous operation is possible.