Integrating the wallbox with Home Assistant

3 min read · Updated 06/2026

The wallbox can be controlled directly from Home Assistant via Modbus TCP. The integration used is the "Heidelberg Energy Control" HACS plugin: Kontron eSystems uses the Heidelberger/Amperfied Modbus register layout under license, which is why the plugin is also compatible with the Kontron wallbox.

Enable the Modbus server on the wallbox

In the web interface, go to "Connections → Modbus Server" and enable the toggle. Without this being enabled, no external system — including Home Assistant — can reach the wallbox via Modbus TCP.

"Modbus Server" page in the web interface with the toggle enabled (screenshot in German).

Install and configure the plugin

In Home Assistant, open the HACS store, search for "Heidelberg Energy Control" (repository: github.com/Schrolli91/heidelberg_energy_control) and install the plugin. Then add a new integration entry and fill in the connection details: as host, the same address you use for the web interface (e.g. `myWallbox.local` or the IP), port 502, device ID 1.

Configuration dialog of "Heidelberg Energy Control" with the fields Name, Host (myWallbox.local), Port (502) and device ID (1) (screenshot in German).

Control the wallbox from Home Assistant

After setup, 17 entities are available in Home Assistant — among them charging enable, target charging current, energy of the current session, vehicle state (connected/charging) and current charging power. The wallbox can be used in automations, dashboards and energy views from there.

Home Assistant card of a wallbox showing charging enable, target current, session energy, vehicle charging/connected state and charging power (screenshot in German).