Low hydrostatic head electrolyte addition to fuel cell stacks

In a fuel cell stack having at least two fuel cells, each said cell including in a horizontal orientation an anode electrode, a cathode electrode and a matrix between said electrodes, a top half-bipolar plate, a bottom half-bipolar plate and a bipolar plate for each two adjacent cells in said fuel stack, said bipolar plate having a top half portion and a bottom half portion, the top portion of said bipolar plate acting as said bottom half-bipolar plate and the bottom portion acting as said top half-bipolar plate, one of said fuel cells being sandwiched between said top half bipolar plate and said bipolar plate, and another of said fuel cells being sandwiched between said bipolar plate and said bottom half-bipolar plate, a fuel path and an oxidant path each extending in a horizontal direction, and electrolyte conduit supply means for supplying electrolyte and filling said fuel cells with electrolyte, the improvement comprising:

• said conduit means for supplying electrolyte to said fuel cells including a path extending in a back and forth serpentine manner through said half-bipolar plates and said bipolar plate and said matrices in a first direction substantially vertically and transverse to said fuel path and said oxidant path, in a second direction substantially parallel to said matrices and said fuel and said oxidant paths, in a third direction substantially vertically and substantially parallel with said first direction, in a fourth direction with a direction of electrolyte flow opposite to said second direction and substantially parallel thereto, and then in a fifth direction substantially aligned with said first direction to produce an overall head uniformly between cells due to frictional pressure drop in said path for each said cell free of a large hydrostatic head to thereby avoid flooding of said electrodes.