Silly question.
I have 400W panel power (40V 10A)
This is used to charge 2 of 100Ah batteries for the invertor.
The invertor is not connected to mains ie. Only the panels charge the batteries. Output of invertor is connected to db via a changeover switch like a genny installation.

Panels charge batteries via controller.

My silly question is what happens with the panel power when the batteries are fully charged ?