A portable system for power generation based on hydrogen and a single proton exchange membrane fuel cell (PEMFC) has been built and operated. The fuel cell is fed in the anode with hydrogen stored in a metal hydrides cartridge, and in the cathode with oxygen from quiescent ambient air (‘air breathing’). The control electronics of the system performs DC–DC conversion from the low voltage (0.5–0.8V) and high current output (200–300mAcm−2) of the single fuel cell, up to 3.3V to power an electronic application. System components assist fuel cell operation, including an electronic valve for anode purging, a fan in front of the open cathode, two supercapacitors for auxiliary power requirements, four LED lights, and a display screen. The influence of the system components on fuel cell behaviour is analyzed. The cathode fan and anodic purging help excess water removal from the electrodes leading to steadier cell response at the expense of extra power consumption. The power system is able to provide above 1W DC electricity to an external application during 20h using 1g of H2. An application consisting of a propeller able to display a luminous message is chosen to test system. It is shown that one single air breathing PEM fuel cell powered with hydrogen may provide high energy density and autonomy for portable applications.