Abstract: The present invention relates to methods and apparatus that can be used for efficient end-of-line (EOL) testing of electrochemical stacks once they are assembled, and prior to break-in or operation of the stack. Rapid test methods and test methods that can be performed in parallel to detect different types of defects are described. Embodiments of the methods and apparatus can be used for testing PEM fuel cell stacks and electrolyzers.

Abstract: Methods and apparatus for detecting electrical short circuits in fuel cell stacks are provided. The methods involve supplying a reactant and an inert gas to a fuel cell stack and measuring the open circuit voltage of fuel cell assemblies in the fuel cell stack. The sensitivity of the methods can be adjusted to detect an electrical short circuit having a resistance at or below a particular threshold short-circuit resistance value, by using a suitable reactant concentration in the method. The methods can include determining a set-point reactant concentration that can be used to detect an electrical short circuit having a resistance at or below a particular threshold short-circuit resistance value.

Abstract: Systems and methods to provide a low voltage interface coupleable between an energy storage device or a DC power source (e.g., fuel cell stack, battery) and one or more AC signal diagnostic systems. The low voltage interface reduces a voltage of the DC power source and supplies the reduced voltage to the one or more AC signal diagnostic systems without affecting the results of the measurements obtained by the one or more AC signal diagnostic systems. Such functionality provides a safer method for performing advanced analysis (e.g., EIS, frequency analysis) while utilizing lower cost and/or smaller components.

Abstract: Methods and apparatus for detecting electrical short circuits in fuel cell stacks are provided. The methods involve supplying a reactant and an inert gas to a fuel cell stack and measuring the open circuit voltage of fuel cell assemblies in the fuel cell stack. The sensitivity of the methods can be adjusted to detect an electrical short circuit having a resistance at or below a particular threshold short-circuit resistance value, by using a suitable reactant concentration in the method. The methods can include determining a set-point reactant concentration that can be used to detect an electrical short circuit having a resistance at or below a particular threshold short-circuit resistance value.

Abstract: Systems and methods to provide a low voltage interface coupleable between an energy storage device or a DC power source (e.g., fuel cell stack, battery) and one or more AC signal diagnostic systems. The low voltage interface reduces a voltage of the DC power source and supplies the reduced voltage to the one or more AC signal diagnostic systems without affecting the results of the measurements obtained by the one or more AC signal diagnostic systems. Such functionality provides a safer method for performing advanced analysis (e.g., EIS, frequency analysis) while utilizing lower cost and/or smaller components.