Owners of a Delta AC MAX EV charger can now read it and start or stop charging from an ESP32, without the vendor app and without the cloud. The new delta_wallbox component was merged into ESPHome on 23 October 2026 and is set to ship with ESPHome 2026.11. It talks to the charger over Bluetooth Low Energy and exposes the data as ordinary ESPHome sensors, so it lands in Home Assistant like any other device.

What it reads and controls

The documentation lists the Delta AC MAX (Basic) as the supported model. Through the component you get:

  • sensors for the charger state, configured current limit (in amperes), charging power (kW), energy of the current session (kWh) and session length (minutes),
  • text sensors for the model, serial number, firmware version, Bluetooth firmware version and current error code,
  • two buttons: start charging and stop charging.

Two things are worth knowing up front. The state sensor publishes the raw byte the charger sends, and its values are not decoded yet. The current limit is read-only, so you can see it but not change it from ESPHome.

Under the hood the driver sends Modbus frames over BLE characteristics. After connecting it pairs, logs in, optionally sets the charger's clock and then polls it, every 15 seconds by default (update_interval).

Setup

You need the password and the six-digit pairing PIN that the Delta app shows when the charger is first set up. The login name defaults to admin and can be changed with user. To find the charger's MAC address, turn on esp32_ble_tracker with debug logging and look for a device whose name starts with JV.

The charger pairs with a passkey, so esp32_ble needs io_capability: keyboard_only and auth_req_mode: sc_mitm_bond. The rest is a ble_client with the charger's MAC address and a delta_wallbox block with the password and PIN, ideally kept in secrets.yaml. If you add a time_id pointing to a time source, the component syncs the charger's clock on every connection, so the charger's own logs carry the right time.

The component runs only on the ESP32 and was tested with the ESP-IDF framework. For anyone who wants solar surplus charging or simple automations such as "stop charging at the start of the peak tariff", a cheap ESP32 placed near the charger is now enough.