A surgical system comprising: a surgical instrument (500, 650) comprising a battery compartment; a protruding member (858, 958, 1158) positioned proximate the battery compartment; and a battery unit (800, 900, 1100), wherein the battery unit (800, 900, 1100) comprises: a casing; a plurality of cells positioned within the casing, wherein at least a portion of the plurality of cells are not electrically connected to one another; a discharge switch (812, 912, 1112) having an open position and a closed position, wherein, when in the closed position, the discharge switch (812, 912, 1112) electrically couples an anode (824, 826, 924, 926, 1124, 1126) of the battery unit (800, 900, 1100) to a cathode (824, 826, 924, 926, 1124, 1126) of the battery unit (800, 900, 1100); wherein the discharge switch (812, 912, 1112) is mechanically biased towards the closed position, wherein the discharge switch (812, 912, 1112) is held in the open position by a non-conductive portion (820, 822, 920, 922, 1120) of the casing, and wherein the discharge switch (812, 912, 1112) is translated into the closed position by the protruding member (858, 958, 1158) upon attachment of the battery unit (800, 900, 1100) into the battery compartment of the surgical instrument (500, 650). a surgical instrument (500, 650) comprising a battery compartment; a protruding member (858, 958, 1158) positioned proximate the battery compartment; and a battery unit (800, 900, 1100), wherein the battery unit (800, 900, 1100) comprises: a casing; a plurality of cells positioned within the casing, wherein at least a portion of the plurality of cells are not electrically connected to one another; a discharge switch (812, 912, 1112) having an open position and a closed position, wherein, when in the closed position, the discharge switch (812, 912, 1112) electrically couples an anode (824, 826, 924, 926, 1124, 1126) of the battery unit (800, 900, 1100) to a cathode (824, 826, 924, 926, 1124, 1126) of the battery unit (800, 900, 1100); wherein the discharge switch (812, 912, 1112) is mechanically biased towards the closed position, wherein the discharge switch (812, 912, 1112) is held in the open position by a non-conductive portion (820, 822, 920, 922, 1120) of the casing, and wherein the discharge switch (812, 912, 1112) is translated into the closed position by the protruding member (858, 958, 1158) upon attachment of the battery unit (800, 900, 1100) into the battery compartment of the surgical instrument (500, 650). a casing; a plurality of cells positioned within the casing, wherein at least a portion of the plurality of cells are not electrically connected to one another; a discharge switch (812, 912, 1112) having an open position and a closed position, wherein, when in the closed position, the discharge switch (812, 912, 1112) electrically couples an anode (824, 826, 924, 926, 1124, 1126) of the battery unit (800, 900, 1100) to a cathode (824, 826, 924, 926, 1124, 1126) of the battery unit (800, 900, 1100); wherein the discharge switch (812, 912, 1112) is mechanically biased towards the closed position, wherein the discharge switch (812, 912, 1112) is held in the open position by a non-conductive portion (820, 822, 920, 922, 1120) of the casing, and wherein the discharge switch (812, 912, 1112) is translated into the closed position by the protruding member (858, 958, 1158) upon attachment of the battery unit (800, 900, 1100) into the battery compartment of the surgical instrument (500, 650).