The invention provides for a fully electrically rechargeable metal-air battery systems and methods of achieving such systems. A rechargeable metal air batten' cell may comprise a metal electrode an air electrode, and an aqueous electrolyte separating the metal electrode and the air electrode. In some embodiments, the metal electrode may directly contact the electrolyte and no separator or porous membrane need be provided between the air electrode and the electrolyte. Rechargeable metal air battery cells may be electrically connected to one another through a centrode connection between a metal electrode of a first battery cell and an air electrode of a second battery cell. Air tunnels may be provided between individual metal air battery cells, in some embodiments, an electrolyte flow management system may be provided.