A cartridge comprises a housing that can be easily attached and detached from an electrolyzer so that the hydrogen generated can be stored within the cartridge. The housing is further configured to easily attach and detach from a fuel cell so that the stored hydrogen can be released to the fuel cell for power generation. In preferred embodiments, the cartridge comprises a cathode that serves to generate hydrogen when joined to the electrolyzer, as well as to store hydrogen. With this arrangement, a single device (the fuel cell cartridge) can function to generate hydrogen when connected to form part of the electrolyzer, to store hydrogen (whether attached to either the fuel cell or electrolyzer or neither--in stand alone form), and/or to supply hydrogen to the fuel cell, when connected thereto.