Date:	April 7, 1998

Objectives:

Complete potentiostatic performance evaluation on the 25 cm2 BCS fuel cell stack, made ,( 0.4mg/cm2, 20% Pt on C). Using standard current vs. Potential and Cyclic voltammetric sweeps, a fuel cell profile will be constructed.

Procedure Utilized:

Standard measurement practice of sweep the voltage from an open circuit potential to a minimum potential of 1.0V and back up to the open circuit potential. The will follow the voltage sweep file 4_01.txt or 4_05.txt. The sweep will be carried out as a Tafel sweep.

Environment:

Temperature-	70 degrees F

Barometer-	NA

Relative Humidity-	NA

Results & Conclusions:

The potentiostatic performance evaluation on the 25 cm2 BCS fuel cell stack was completed successfully at 30°C. The production water is faster at elevated temperatures and higher power constraints, as expected. The self humidification is hampering the performance more than expected, and there is a resistance problem in the stack as exemplified by 4-6-98b.