Abstract: Fuel cell based backup unit apparatus for storage subsystems are provided. With the apparatus, at least one fuel cell is provided as part of a fuel cell power generation array that is used to provide backup power to a storage subsystem of a computing device, such as a RAM cache. A regeneration mechanism is provided for regenerating the fuel in the at least one fuel cell. A logic and control module is provided for controlling the overall operation of the backup unit including determining when to provide backup power and when to initiate regeneration of the fuel cells. A DC/DC voltage conversion module may also be provided for converting a DC output from the fuel cell power generation array into an output useable by the storage subsystem. In a hybrid embodiment, both a fuel cell power generation array and a lead-acid battery pack cache backup array may be utilized to provide backup power for a storage subsystem.