Plug holder for installing plug end

A plug holder for installing a male plug end of a battery charger on a vehicle, the plug holder comprising:

• an outer housing having a front end defining a plug opening and a back end defining a back opening, wherein the outer housing is attachable to a vessel hull and configured to hold a male plug end of a battery charger within the outer housing such that it is accessible through the plug opening;
• a removable sleeve that fits within the outer housing and is shaped to secure the male plug end within the outer housing such that it does not move when connecting or disconnecting to the male plug end, wherein the removable sleeve is configured to receive the male plug end only in an upright orientation;
• at least one key element on the removable sleeve configured to mate with a corresponding key element on an inner wall of the outer housing, wherein the key element and the corresponding key element are configured to require that the removable sleeve can only be inserted into the outer housing in a predefined orientation that maintains the male plug end in the upright orientation;
• a back stop removably connectable to the back end of the outer housing to cover the back opening, wherein the back stop is configured to retain the removable sleeve and the male plug end within the outer housing;
• wherein the outer housing and the back stop are also configured such that the male plug end can be maintained loosely within the outer housing without the removable sleeve.