A:AnswerThe Clock radio requires AC power. It has a battery backup to save your settings in case of a power loss, but you can not use the radio or clock without plugging it in
A:AnswerThe end of the plug has a big brick, but the side that plugs into the alarm clock is very small and you'll be able to snake it through a small hole
A:AnswerThe batteries are for backup. When on battery, the time display goes out, but keeps the time and alarms and settings.
Therefore, it is not useful to run on batteries only.
A:AnswerMy radio also has an empty back where the power plugs in. Mine has tabs and notches that look to be for a cover, but I also did not get one. These may be for another model, or they could be for removing the front face for repair.
A:AnswerThe battery backup is only to keep the settings and time. However, the time display does not operate on battery, so not useful until plugged in.