Multi-RS Solar-ac coupling-ac in conected to grid,solar excess with battery full will go to grid?

Hello all,

I’m from Portugal and I have a solar grid tie installation with SAJ.
Now, I’m planning to add the Multi-RS Solar in ac coupling.
From what I have read it should works as:
- ac in with power from grid
solar excess from my grid tie will be used by Multi-RS to charge his battery
in case Multi-RS battery is full, solar excess with be sent to grid (? this is my doubt)
- ac in with NO power from grid
solar excess from my grid tie will be used by Multi-RS to charge his battery
in case Multi-RS battery is full, Multi-RS will shift the frequency in order to my grid tie stop generating energy

Have also another question, can I use the Multi-RS solar in Portugal?
Where can I check that?

Thanks in advance,
Mario