An enclosure of a power source for medical treatment devices includes a handle portion extending from a first surface of the enclosure. The handle portion includes a standoff extending away from the first surface, and a flange extending transversely from the standoff and defining a plane that is generally parallel to the first surface. Together, the first surface, the standoff, and the flange define an open annular space. A power cable may be wound about the standoff to at least partially occupy the open annular space. One or more notches in the flange are configured to seat the power cable to secure its loose end(s). In this manner, the power cable can be safely stored to reduce the risks that the power cable may become damaged, may interfere with other devices in the treatment area, or may be misplaced.
