High temperature fuel cell stacks, like solid oxide fuel cells and molten carbonate fuel cells, are far too large and heavy. The reasons for this include the very high power density of the technology, which is a prerequisite for packaging the stacks in the limited space available, as well as some severe problems with the other technologies in a road vehicle that uses air to supply the cathode side of the fuel cells. Proton exchange membrane fuel cell stacks have been most commonly used in FCEVs, and today this is the only technology considered by the industry for FCEVs. Karl Kordesch used an alkaline fuel cell stack in his famous car in 1970, and others used phosphoric acid fuel cell stacks ( Eichelseder and Klell, 2012). In the early days of FCEV development, a number of different FC technologies were installed in road vehicles.

Wind, in Compendium of Hydrogen Energy, 2016 1.4.1 Fuel cell stacks The AFC could thus be shut down completely – and the electrolyte could even be completely drained from the system – and the vehicle could still be moved by the battery power. A diode was installed to prevent the batteries from electrolyzing water in the AFC when the AFC voltage was lower than the battery voltage (e.g., because no reactants were supplied to the AFC). The batteries were thus automatically recharged by the AFC. When the propulsion system was operated with low electrical output power levels, the voltage of the AFC stacks exceeded the voltage of the lead–acid batteries. Seven 12 V lead–acid batteries, located in the engine compartment of the vehicle, were electrically connected in series and operated in parallel to the hydrogen/air AFC. The fuel cell system was therefore easily accessible from the passenger cabin as well as through the trunk. The picture was taken from the passenger cabin looking toward the opened trunk lid. The two manometers located on the left- and right-hand side of the soda lime container are used for pressure and flow indication. The soda lime container is therefore subdivided into six compartments in order to enable a simple visual identification of the soda lime condition by tracing the blue region of used soda lime, located near the air inlet duct, toward the fuel cell supply line. Fresh soda lime is red and turns blue when used for carbon dioxide scrubbing due to an optical indicator. The transparent plastic container located on top of the stacks contains soda lime. Each stack has a voltage of 30 V and an electric output power of 2 kW. Six-kilowatt alkaline fuel cell (AFC) stacks in the rear of Karl Kordesch's car.

City car driving 1.4.1 chevy nova