meaning that the A/C output of the batteries are connected to a dedicated panel, and there is some logic in the software that says if the inverter has a battery, and that battery is full, then turn on the output to the A/C, otherwise, don't output anything? That's interesting. What is the use case? If your load exceeded your capacity, or the duration you run the load would exceed the capacity, what good would that do?
Example: I have a pool pump, a battery, inverter, and panels. When the time of day hits 10 AM, pump starts, and ends at 4 PM. While running, it uses about 1000 watts, but I have 1200 or so coming in from the panels. Therefore, what I see is some of the PV output going to the load directly, and the rest charging the battery. However, if it were to be cloudy, I have nothing that prevents the pool load from starting.
Is that the situation you're trying to protect for?