Portable Fuel Cell generators are electrochemical devices that continuously convert the chemical energy of the fuel (hydrogen) and an oxidant (air) into DC electrical energy.

A polymeric membrane fuel cell conventionally comprises a negative electrode (anode) and a positive electrode (cathode) including a suitable catalyst and arranged with a stacked relationship in a polymeric electrolyte. In these cells hydrogen operates as a fuel and it supplies the anode, whereas oxygen or simply air enters the fuel cell from the cathode side. More specifi cally, hydrogen atoms are split into protons and electrons which migrate toward the cathode through different paths, protons through the polymeric electrolyte whereas electrons provide a continuous or direct current which can supply an outer circuit. Near the cathode, protons and electrons are recombined with oxygen to again provide water molecules. This reaction is facilitated by the provision of a catalyst, a chemical substance speeding up the process, and intervening into the reaction without being consumed. From a chemical energy to electric energy transforming standpoint, the system can be nearly assimilated to a battery, however it is not subjected to discharges, and the reactor merely produces electric power due to the presence of fuel.

Thus, if the fuel cell is used instead of a secondary battery, the recharging time will be related to the time necessary for replacing the cartridge, instead of several hours which would be necessary for recharging an accumulator pack. Moreover, transforming chemical energy into electric energy, without combustion, provides an absolutely clean and non-polluting process, since the single residue will consists of water steam.

Conventional portable power generators convert chemical energy of the fuel into heat and then to mechanical energy, which is finally converted into electrical energy. A portable fuel cell by-passes all these energy conversion processes and provide a reliable, constant supply of electrical energy without moving parts and operating at low temperatures.