Patent ID: 6911277

Claim:
A fuel cell stack, comprising: a plurality of fuel cells provided in a stacked relationship; a plurality of reactant gas passages disposed between said plurality of fuel cells; and a manifold system in communication with said plurality of reactant gas passages, said manifold system including a flow control mechanism that is adjustable to provide alternative flow path arrangements through said plurality of reactant gas passages, said alternative flow path arrangements include said flow control mechanism connecting said plurality of reactant gas passages in differing parallel and series flow connections in which a first subset of said plurality of reactant gas passages are connected to said manifold system for parallel flow relative to one another and a second subset of said plurality of reactant gas passages are connected to said manifold system for parallel flow relative to one another and are connected in series flow relationship to said first subset such that said flow control mechanism is adjustable to change which of said plurality of reactant gas passages are connected in parallel flow relationship and which subsets are connected in series flow relationship.