You see the front panel in the first photograph, well you remove that in order to connect the battery cord when you receive the unit. All APC units are shipped with the batteries disconnected.
The front panel is actually quite annoying. These units are extremely heavy and I have lifted a unit twice from the floor (crouching at the rear of the unit) with one hand grasping by mistake the front panel. Of course the panel detaches accidentally and the front of the unit slaps down hard on the floor. Not enough to cause damage as it has happened before the front of the unit reaches 10cm from the floor. It is something to be careful of though. Drop one on your foot and you will not be walking properly for a while. Live and Learn.