A fuel cell stack includes fuel cells with anode and cathode water transport plates having porosity of at least 50%, thereby to significantly increase the amount of water stored within the water transport plates when the stack is shut down, which doubles the heat of fusion as the ice in the pores melts during a startup following freeze. The transmitters are coupled to select an operational mode from a group of operational modes and to operate in the selected operational mode. A second input data representative of the second parameter of the cryogenic medium in the cooling system is estimated. A state machine running on the portable computer system’s Super IO compares the identification signal and a power available signal from an internal charger to determine state of the external power source and indicate the state to a user. A metallic cap with a peripheral rim is also provided to protect the ends of the composite material of the face insert.