I built a DIY wallbox by using:
- DomBusEVSE module
- RCCB + energy meter + contactor + EV cable
- Connection between EVSE module and raspberry by a RS485/USB adapter
- DomBusGateway software (python) preforming DomBus 2 MQTT AutoDiscovery
When DomBusGateway is installed and EVSE module connected, HomeAssistant automatically creates all entities to manage: - charging by using only solar energy
- charging by adding 25-50-75-100% of energy from the grid
- charging using only solar energy but limiting the charging power just to keep the voltage to the specified value: I use this feature to keep voltage at 248V during these sunny days, preventing overvoltage (253V in single phase) causing solar inverter derating
Although DomBusEVSE supports connection to an energy meter to measure how much power is drained from the grid, if a grid meter already exists it’s sufficient a silly automation to send grid power to the EVSE. The same can be done by hybrid inverter, sending to the EVSE GridPower - BatteryPower so, setting charging in SOLAR mode, it uses only energy from photovoltaic without draining the house battery
This is the link of DomBusGateway github project where it’s possible to download the python software that permits to manage the wallbox by MQTT AutoDiscovery.
