In Germany, the Fraunhofer ISE is undertaking the LiteFCBike project, which is developing a compact fuel cell system offering a fully-fledged replacement for a pedelec battery. The Fraunhofer ISE is currently presenting this hydrogen technology at the Hannover Messe.
The basis for the FC system is the “Conodrive” drive concept, a retrofittable drive that drives the rear wheel with a special drive roller. In cooperation with the Conodrive developer José Fernandez, the aim of the project was to develop a light and practicable system for users.
Developers have used the same Polymer electrolyte membrane fuel cells (PEMFC) as are used for automotive applications. To save weight and volume, two fuel cell stacks with open cathode are used with no liquid cooling circuit. In order to fluidly connect all components, the researchers developed a compact fluidics module to which all components are connected, making pipes and connectors superfluous. Easily available metal hydride cartridges are used as “tanks” that can be filled with a suitable small electrolyser. A pressure tank would also be possible with a larger space available (load wheel) in order to achieve significantly greater ranges with short refuelling times.
During nominal operation, the fuel cells produce about 70 watts of electrical power and recharge the buffer battery. In the support phases, the usual 250 watts used for a pedelec are available. The total dimensions of the complete system with tank and control electronics are 348 x 153 x 47 mm, the net energy content of a refuelling about 270 Wh.