In a battery-powered electrical device, an expandable battery compartment for accommodating batteries of varying size, and a method for altering the size of the battery compartment, is disclosed. The battery compartment includes a battery casing defining a substantially cylindrical recess for at least partially encapsulating a battery. The recess has an open end for receiving a battery and a closed end. A first electrical contact element is positioned on or adjacent the closed end of the recess for contacting a terminal of a battery. A cover is configured to be releasably mounted to the open end of the recess for selectively concealing the open end and defining the battery compartment. A second electrical contact element is provided for contacting an opposing terminal of the battery. The second electrical contact element is selectively positionable at multiple locations on the cover to accommodate batteries of varying size within the battery compartment.