I am trying to use a battery from an EV, maybe BMW i3 or even the tesla battery. i3 would be nice since the voltage is in a good range. With a Tesla battery I would need to use the whole pack with 60 to 100 kWh to have a good voltage, which might be a bit oversized.
So am trying to simulate the BYD battery for the existing Kostal inverter.
I also thought about using another inverter. I like the Victron pars for its uninterruptible power supply and fast transfer switches. But they are using only single phase concepts. So I would need 3x the MultiPlus || and the SmartSolar RS to have a tree phase system which lead to additional cost for the inverter of around 7 k€. With this system I would have the UPS but thats not worth it.
I am working as electrical engineer for a german company which builds cell management controller, battery management controller and battery junction boxes for different OEMs so I know what I am doing.
Only unusual thing for me is to not having a description of the protocols and buses.