A circuit interrupting device for use with a electrical power distribution system includes a housing containing a circuit interrupting mechanism. A battery tube is positioned in the housing. A battery assembly is configured to be inserted into the battery tube. The battery assembly includes a battery assembly body having a first end and a second end. A battery is positioned in the battery assembly body. The battery assembly is configured such that both a positive contact and a negative contact are exposed from the second end of the battery assembly body. In some embodiments, the battery assembly includes a keyed portion mates with the battery tube to ensure alignment of the battery assembly in the battery tube.