unicast

Hi guys, I'm new to this forum, so let me introduce my setup a little. I currently have 5 kWp (5p3s 340 Wp) on the roof, almost 50 kWh in my homemade battery packs, and an old 5 kW Axpert King I inverter. There is currently no other connection between my system and the power grid besides the PE wire. It has been working pretty well for more than three years and it usually fulfills my power needs from early March to late November, providing about 3 MWh per year.
However, the system is being expanded, mostly because of the harsh European climate with cold, dark, sometimes snowy winters and cloudy, foggy autumns. I also discovered that the 5 kW inverter output limit is a major limitation in some situations. Therefore, another 4 kWp is ready on my barn and garage, and another Axpert King I is prepared next to the first one. I am going to run them in a single-phase parallel configuration.