Battery cap for a battery cell of a mobile electronic device

To reduce tolerances of alignment means of battery packs (28) and to simplify the manufacturing process a cap (2) is used which provides the mechanical and electrical connection between a battery cell (4) and a mobile electronic device. The cap (2), separately manufactured and subsequently attached to the battery cell (4), comprises at least one contact (12, 16) for a detachable electronic connection with the mobile electronic device, and first alignment means (44) for engaging with alignment means of the mobile electronic device to align the contact (12, 16) with respect to a corresponding contact of the mobile electronic device.