A battery with a cell housing having at least one fluid entry port for the passage of a fluid into said cell housing; a first fluid consuming electrode disposed within said cell housing; a second electrode disposed within said cell housing; and a fluid regulating system disposed so as to selectively allow fluid to enter into said at least one fluid entry port so as to reach said first fluid consuming electrode, wherein said fluid regulating system comprises: a moving plate disposed adjacent an outer surface of said cell housing and having at least one plate aperture for moving in and out of alignment with said at least one fluid entry port, and an actuator comprising a shape memory alloy component for moving said moving plate when heat is applied to said shape memory alloy component. An alternative independent claim includes an actuator for moving said moving plate, and a lid covering said moving plate and providing a passage for fluid to said moving plate.