Systems and methods involve a case, adapter, and portable electronic device, the system includes at least one base; at least two walls positioned on either side of the at least one base; at least one slot defined at least in part by the at least two walls and the at least one base; at least one post extending from the at least one base; and at least one interface including at least one electrically conductive contact extending from the at least one base. In addition, other aspects are described in the claims, drawings, and text forming a part of the present disclosure.