The separator must be porous for ions to
flow between the anode and cathode. To prevent development
of the electrical conductance between the positive and negative
electrodes stemming from dendritic formation of lead particles,
the separator should preferably be micro-porous. In a flooded
or a gelled electrolyte lead-acid battery, the separator typically
will have protrusions (i.e., ribs) projecting from the planar surface
of the substrate, and typically aligned in the lengthwise
direction of the plate