Patent ID: 7112379

Claim:
A method of initiating operation of an electric load powered by a proton exchange membrane (PEM) fuel cell stack at least part of which is at a temperature below the freezing temperature of water, said stack having a plurality of cells and having water passages connected to a water circulation system to provide at least one of (i) product water removal (ii) condensate removal (iii) humidification of reactants, and (iv) cooling, each of said cells including a MEA disposed between an anode support plate and a cathode support plate, a fuel reactant gas flow field on an anode side of said cell, and an oxidant reactant gas flow field on a cathode side of said cell, said method comprising: (a) monitoring the current provided by and voltage across said stack; (b) evacuating said water passages so as to provide the pressure of any water in said water passages at least 4kPa (0.6 psi) below the pressure of said reactant gases; (c) with said stack disconnected from said load, providing at least stochiometric requirement of fuel reactant gas to said fuel flow fields and at least stochiometric requirement of oxidant reactant gas to said oxidant flow fields; and (d) after said step (c), connecting said stack to power said load.