This recommended practice is intended to serve as a procedure to verify the functional performance, design specifications or vendor claims of any PEM (Proton Exchange Membrane) type fuel cell stack sub-system for automotive applications. In this document, definitions, specifications, and methods for the functional performance characterization of the fuel cell stack sub-system are provided. The functional performance characterization includes evaluating electrical outputs and controlling fluid inputs and outputs based on the test boundary defined in this document.

In this document, a fuel cell stack sub-system is defined to include the following:

Fuel cell stack(s) - An assembly of membrane electrode assemblies (MEA), current collectors, separator plates, cooling plates, manifolds, and a supporting structure.

Connections for conducting fuels, oxidants, cooling media, inert gases and exhausts.

Electrical connections for the power delivered by the stack sub-system.

Devices for monitoring electrical loads.

Devices for monitoring cell voltage.

Humidification devices.

Instrumentation for detecting normal and/or abnormal operating conditions.

Enclosures (that may qualify as pressure vessels), and ventilation systems for the enclosure.

Not included in the sub-system are the following:

Fuel and air processors

Thermal management system

Power conditioner and distributor

Controllers