AC200max expansion battery - auto turn on with solar

Every evening when my ac200max shuts off due to no solar input, the main unit and the expansion battery both turn off. This is good, however in the morning when the fixed solar array comes online, only the main unit turns on. The expansion battery stays off.

This leads to a persistent imbalance between the two batteries. Apart from going into the garage and turning on manually turning on the expansion battery every morning, what are my options?

I have the 500w solar charging brick also. Is there some safe configuration I could use to wake and charge the expansion battery as well as the main unit, when I only have a single solar input?

I am sorry after the battery pack is discharged to 0, PV cannot activate it and can only be turned on manually.