Abstract: A method and system are provided for measuring impedance and voltage characteristics of individual cells of multi-cell electrochemical devices, for example a battery or a fuel cell stack. The electrochemical system comprises a plurality of cells; a measuring device including a plurality of inputs connected across the plurality of cells to generate voltage and current signals indicative of voltage and current characteristics of the plurality of cells; a current supply/draw means for superimposing modulated current values through the plurality of cells; and a controller for controlling at least one system operating condition based on the voltage and current characteristics received from the measuring device, the controller being connected to the measuring device.

Abstract: A fuel cell power system has a plurality of fuel cell power modules, each module including a fuel cell and associated peripheral devices. Each fuel cell power module is controlled by its own local controller. A master controller controls each of the local controllers in accordance with overall system requirements. Optionally, a bypass allows the master controller to shut down and bypass a particular fuel cell power module, providing this system with greater flexibility, robustness and reliability. The modular system architecture also simplifies manufacturing, maintenance and repair.

Abstract: The electrical energy produced by a fuel cell under test is typically dumped in the form of heat energy radiated from a controllable variable load included in a conventional fuel cell testing system. This practice is wasteful since the electrical energy produced is not immediately employed to do useful work, stored for later use or sold to a power company after appropriate conversion. According to aspects of some embodiments of the present invention there is provided a fuel cell testing system having an energy conversion system that converts electrical energy produced by a fuel cell under test into another reliable form of energy that can be employed for some useful end, as opposed to simply dumping it as radiated heat energy.