A caseback has multiple, arc-shaped, ferrous, metal contacts that serve a dual purpose. The metal contacts i) establish an input connection between a battery for the wearable electronic device and charging prongs of a charger and ii) establish a magnetic coupling between the wearable electronic device and multiple magnets in the charger to hold the metal contacts of the wearable electronic device and the charging prongs of the charger in place during a charging of the battery. A male extension extends from a surface of the caseback to couple into a female receptor of the charger. i) The ferrous metal contacts' relationship with a positioning of the magnetics in the charger in combination with ii) the male extension coupling into the female receptor use magnetic and mechanical coupling to establish and control an alignment of the metal contacts with the charging prongs in three dimensions, a Z-axis, an X-axis, and a Y-axis.