Abstract: Embodiments of the pertinent invention relates to apparatus, systems and methods for diagnostic testing of an electrochemical cell stack, such as a fuel cell stack or an electrolyzer cell stack. According to one embodiment, the apparatus comprises a multiplexer for switching current to one or more cells in the electrochemical cell stack, a voltage monitor for monitoring the voltage between the anode plate and the cathode plate of one or more cells, a power supply module for supplying power to the multiplexer and a gas supply module for supplying fuel gas and non-fuel gas to the electrochemical cell stack. The apparatus further comprises a control module electrically connected to and configured to control the multiplexer, the voltage monitor, the power supply module and the gas supply module to conduct automatic diagnostic testing of the electrochemical cell stack.

Abstract: A mobile power supply system for use in vehicles, and components of the mobile power supply system. The power supply system is a regenerative fuel cell system. The system combines a fuel cell unit, an electrolyzer unit, and a hydrogen storage unit. Design improvements over known regenerative fuel cell systems are incorporated into the system of the present invention.