FWIW I’ve only just started playing with Home Assistant and am playing with getting this working. I also am using Amber Energy (in Australia) who have a dynamic wholesale price and decent Home Assistant integration giving a feed of the price.
In my case I’m so far just using the automatic HA Envoy integration which seems to include an inverter sensor sensor.envoy_<ENVOY_SERIAL>_inverter_<INVERTER_SERIAL> that goes to the battery. This sensor gives a negative value when the battery is charging, and a positive value when it is discharging.
I’m still fiddling with this but using the following posts I’m pretty sure I can setup sensors and integrations of that one sensor to give me everything needed for the battery;
When I get this working nicely I’ll post an update.