An electrochemical cell system for generating electrical current using a metal fuel and an oxidant, the cell system comprising: an electrochemical cell comprising: (i) a fuel electrode comprising N permeable electrode bodies (12a-12d) arranged in spaced apart relation in order 1 to N, wherein N is an integer greater than or equal to two, the fuel electrode comprising metal fuel on the permeable electrode bodies (12a-12d); (ii) an oxidant electrode spaced apart from the fuel electrode; and (iii) a liquid ionically conductive medium communicating the electrodes for conducting ions to support electrochemical reactions at the electrodes; wherein the fuel and oxidant electrodes are configured to, during a discharging mode, oxidize the metal fuel on the permeable electrode bodies and reduce the oxidant at the oxidant electrode, thus generating a potential difference for application to a load; a plurality of switches (150, 180, 190, 200) for selectively coupling each permeable electrode body of the fuel electrode to the load, each switch being associated with one electrode body; one or more sensors associated with the permeable electrode bodies, configured to determine the presence of consumable fuel on each of the permeable electrode bodies; and characterised in that the electrochemical cell system comprises a controller configured to control the plurality of switches during the discharging mode so as to disconnect from the load each of the permeable electrode bodies which the one or more sensors detect has the fuel depleted therefrom, such that the permeable electrode bodies are subsequently disconnected from the load, starting with the electrode body that is closest to the oxidant electrode. an electrochemical cell comprising: (i) a fuel electrode comprising N permeable electrode bodies (12a-12d) arranged in spaced apart relation in order 1 to N, wherein N is an integer greater than or equal to two, the fuel electrode comprising metal fuel on the permeable electrode bodies (12a-12d); (ii) an oxidant electrode spaced apart from the fuel electrode; and (iii) a liquid ionically conductive medium communicating the electrodes for conducting ions to support electrochemical reactions at the electrodes; (i) a fuel electrode comprising N permeable electrode bodies (12a-12d) arranged in spaced apart relation in order 1 to N, wherein N is an integer greater than or equal to two, the fuel electrode comprising metal fuel on the permeable electrode bodies (12a-12d); (ii) an oxidant electrode spaced apart from the fuel electrode; and (iii) a liquid ionically conductive medium communicating the electrodes for conducting ions to support electrochemical reactions at the electrodes; wherein the fuel and oxidant electrodes are configured to, during a discharging mode, oxidize the metal fuel on the permeable electrode bodies and reduce the oxidant at the oxidant electrode, thus generating a potential difference for application to a load; a plurality of switches (150, 180, 190, 200) for selectively coupling each permeable electrode body of the fuel electrode to the load, each switch being associated with one electrode body; one or more sensors associated with the permeable electrode bodies, configured to determine the presence of consumable fuel on each of the permeable electrode bodies; and characterised in that the electrochemical cell system comprises a controller configured to control the plurality of switches during the discharging mode so as to disconnect from the load each of the permeable electrode bodies which the one or more sensors detect has the fuel depleted therefrom, such that the permeable electrode bodies are subsequently disconnected from the load, starting with the electrode body that is closest to the oxidant electrode.