A battery-powered system includes a device and a battery. The device includes a recess for receiving the battery and an electrical contact disposed at the bottom of the recess. The device includes front and back guide elements and a spacer with a raised portion and a ramp. The battery has front and back guide elements constructed to mate with corresponding front and back guide elements of the device such that when the guide elements are mated, the battery is in a locked position. A battery electrical contact is disposed along the device-facing major surface, constructed to operatively couple with the device electrical contact. The spacer is constructed to reduce wear and damage to the electrical contacts by reducing contact with the electrical contacts while the battery is moved long the spacer.