Alfen Modbus for Home Assistant

Home Assistant integration for Alfen Eve NG9xx series EV chargers via Modbus TCP.

Features

• 🔌 Real-time monitoring - Voltage, current, power, energy for all phases
• 🚗 Car status detection - Connected, charging, disconnected states
• ⚡ Load balancing control - Set maximum charging current dynamically
• �️ Max current protection - Prevents setting current above station limit
• �📊 Session tracking - Energy consumed and duration per charging session
• 🔄 Auto-renew max current - Prevents timeout to safe current mode
• 🏢 Multi-socket support - Works with dual socket chargers
• 🌐 SCN support - Smart Charging Network (partial)

Requirements

• Home Assistant 2024.4.0 or newer
• Alfen Eve NG9xx charger with:
  • Firmware 4.2.0 or newer (Modbus TCP support)
  • Firmware 6.4.0+ recommended (fixes power budget reset bug)
  • Active Load Balancing license enabled
• Modbus TCP enabled on the charger

Installation

HACS (Recommended)

1. Open HACS in Home Assistant
2. Search for "Alfen Modbus"
3. Click Install
4. Restart Home Assistant

Manual

1. Copy custom_components/alfen_modbus to your config/custom_components/ folder
2. Restart Home Assistant

Configuration

1. Go to Settings → Devices & Services
2. Click Add Integration
3. Search for Alfen Modbus
4. Enter your charger's IP address and port (default: 502)

Enabling Modbus on Alfen Charger

1. Acquire the Active Load Balancing license from Alfen
2. Enable Active Load Balancing via the Alfen Service Installer app
3. Set Data Source to "Energy Management System" for slave mode

See the Alfen Smart Charging Manual for details.

Sensors

Category	Sensors
Device	Name, Manufacturer, Serial, Firmware, Platform
Station	Max Current, Temperature, Backoffice Connection
Socket	Voltages (L1-N, L2-N, L3-N, L1-L2, L2-L3, L3-L1)
	Currents (L1, L2, L3, N, Sum)
	Power (Real, Apparent, Reactive per phase + Sum)
	Energy (Delivered, Consumed per phase + Sum)
	Mode 3 State, Availability, Charging Phases
Derived	Car Connected, Car Charging, Session Wh, Session Duration

Controls

Control	Description
Max Current	Set the maximum charging current (load balancing)
Phase Mode	Select 1-phase or 3-phase charging

Known Issues

• Power budget may reset to 0A when no car is connected (fixed in firmware 6.4.0-4210)
• Reallin power meter (post-2021): Chargers with a Reallin power meter produced after 2021 only export a subset of measurement values. Per-phase energy, apparent energy, and reactive energy sensors will show as "unavailable" (NaN). This is a hardware limitation, not a bug.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Changelog

v1.0.0

• Stable release - First stable release for HACS
• Binary sensors - Added car_connected and car_charging binary sensors
• Improved config flow - Enhanced UI with descriptions and connection testing
• Options flow - Reconfigure host, port, and settings after setup
• pymodbus 3.11 compatibility - Updated API calls for latest pymodbus

v0.2.0

• Max current protection - The max current slider now dynamically limits to the station's actual max current (Register 1100), preventing values higher than the hardware allows
• pymodbus 3.11 compatibility - Updated API calls to use device_id parameter (replaces deprecated slave)

v0.1.9

• Initial release

License

This project is licensed under the Apache 2.0 License - see the LICENSE file for details.