A zinc-air cell wherein the zinc was present as a bed of particles and the electrolyte circulated by concentration driven natural convection is described. The circulation was from top to bottom within the bed with return channels on either side of the bed. Velocity measurements were made in the channels by laser-Doppler velocimetry and reached a peak of up to 0.9 mm/s (corresponding to a superficial velocity of about 38 mu m/s in the bed) early in a constant current discharge. Velocities were satisfactorily predicted by the mathematical model described in Part I. The potential drop across the anode chamber was measured and showed fair agreement with the mathematical model. The model was used to make predictions concerning changes in cell design or operation.