Abstract: Rechargeable metal-air battery systems comprise a plurality of plate groups (40) disposed within a battery cell (12) and have input and output conduits (13, 14). A fluid electrolyte is circulated through the battery cell by a pump (22) and regenerated by a divester (20) for recirculation through the battery cell (12). The divester (20) divests the particles of active material suspended within the electrolyte of their oxide layer resulting from passivation caused by the electrolyte solution being saturated with oxide. The divester (20) performs its function by bringing the particles of active material into frictional contact with one another. The battery system (10) constructed in accordance with the present invention may be chemically recharged by removing the spent active material suspended within the electrolyte and replacing it with new active material.