Unfortunately there is no step-by-step guide how to implement a new battery device. As I implemented an ESS/inverter/grid-meter device for my SolarEdge home system by myself and as I am not a good java programmer I did it this way:
- Implement a device like described in the getting started guide
- Look at the code how the others did it. Sounds trivial. In fact the main thing is to get the battery´s data via modbus. This mainly depends on the device’s documentation.
So, often it is necessary to add own device specific channels in the interface file.
The first milestone is to be able to read the device´s data, e.g. SoC, ActivePower, Charge/Discharge-Power.
The next step would be controlling the battery. Therefore you have to implement the applyPower-Method that tells the battery what to do. Stefan described it in this thread