Here is a graph of my panel/battery voltage
The batt and panel have the same voltage until the 14.6v batt set pt is reached.
At that time, panel V seems to rise, this is PWM, connecting and disconnecting the panel to limit power to the battery to maintain the set pt V. Connected, the panel voltage = batt V, disconnected, the panel voltage is Voc, the controller's V meter reads this as an average and as more time is spent disconnected, the panel V rises. The lower panel V after it peeks ~20V is due to low light conditions, the controller goes to float (13.4v) ~noon.
Data captured from a View Star 1024BN
Here's my concept of 50% PWM duty cycle, the controller displays 'PV 17.9v, 2A', 'Batt 14.8v, 2A'
