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: Methods, systems, and techniques are provided for acquiring fuel cell polarization data, obtaining fuel cell polarization parameters from the fuel cell polarization data, and validating the reliability of the obtained data and parameters. In some aspects methods for acquiring and parameterizing proton exchange membrane fuel cell polarization data include measuring at least one current-voltage point for an operating fuel cell, and determining at least one polarization parameter of the fuel cell by evaluating a closed form solution using the at least one current-voltage point.

Abstract: Described herein are a channel, system and method for monitoring voltages. Typically, the system includes multiple channels, each for sampling one of the voltages. The channels are physically and electrically coupled to a back end board on which is mounted a field programmable gate array (FPGA) that instructs the channels to simultaneously sample the voltages. Optionally, the channel is powered using an power supply that is isolated from the back end board, and transmits information over an electrically isolated connection to the back end board. The channel also includes voltage signal processing circuitry for processing the voltage signal on board the channel, and has stored on it channel identification information composed of at least one of an operating mode of the channel and a serial number of the channel, which can assist with voltage signal processing.