Disclosed is a portable fluid dispensing device for infusing a fluid into the body of a user and/or for sensing an analyte within the body. The device includes at least one housing to retain a source of energy to energize the device, the source of energy comprising at least one electrochemical cell to produce electrical energy upon exposure of the cell to air, and a seal to prevent exposure of the at least one cell to air when the source of energy is not in use and to enable exposure of the at least one cell to air prior to energizing the device with the source of energy. The at least one housing includes an opening to provide access to the seal to enable actuation of the seal to control exposure of the at least one cell to air.