Abstract: A portable fuel cell system that is compact. The integration of a snorkel into the chassis allows the fuel cell to operate inside a backpack. The fuel cell system includes a thermal management system to keep the surface of the chassis at a comfortable temperature for the user. A boiler is mounted on a side of the fuel cell stack such that waste heat from the fuel cell stack is efficiently transferred to the boiler to vaporize fuel. A burner is positioned away from the fuel cell stack so that the system can be more compact. A thermal management system, including a blower, a heatsink, and a cooling air shroud, regulates the temperature of the fuel cell system.

Abstract: A fuel cell power system that includes multiple strings that each have multiple sub-stacks of fuel cells. Each sub-stack is electrically isolated from other sub-stacks and each sub-stack can be independently controlled by a DC control module on a printed circuit board. The DC control module of a sub-stack can regulate or shut off the output power of the sub-stack if the sub-stack becomes weak or fails. A sub-stack can be shut off while other sub-stacks in the system continue to operate. The output power of other sub-stacks can be increased to compensate for sub-stacks that are shut down.