The present invention includes a portable battery with a shaped positive terminal that may be used as a tool for engaging a battery door fastener. The terminal protrudes from the positive end of the battery similar to a traditional cap and base battery terminal. The shape allows the positive terminal to engage with a battery door fastener and, when the battery is rotated, drive the fastener into either an open or closed position. This allows the battery door to be locked or unlocked without the hassle of locating a separate tool. To replace a battery, a person uses the replacement battery to disengage the battery door fastener, opens the battery door, replaces the used battery, then closes the door and reengages the fastener with the used battery. The shaped terminal may also serve as a three dimensional identifier for which end of the battery is the positive terminal.