SmartCharge - EV Charging Station Monitor

A Home Assistant integration for monitoring EnBW electric vehicle charging stations in Germany and tracking how green the energy is when charging your EV.

Features

• Car Green-Charging Tracker: Add your car and its GPS tracker to see live CO₂ intensity and accumulated charging stats using the Electricity Maps Home Assistant integration
• Persistent Accumulators: Energy, CO₂, and cost totals survive Home Assistant restarts — nothing is lost
• Proximity-Based Billing: Costs are automatically billed when the car is near a configured station. One-off session base fees are applied once per session start; per-kWh cost accrues continuously
• Multiple Station Types: EnBW public stations, custom home wallboxes, and temporary one-off stops — all handled with accurate billing
• Auto-Discovery: Optionally let SmartCharge detect nearby EnBW stations automatically while the car is charging and prompt you to add them
• Easy Configuration: Search nearby stations on a map or enter a station ID directly — one config entry per station
• Custom Friendly Name: Set a custom static part of the sensor's friendly name during setup or reconfiguration
• Single Entity per Station: One sensor per station showing available or occupied, with a dynamic name like 2 / 5 - StationName. For stations with more than 9 charge points, the available count is spaced (e.g. 1 0 / 10 - StationName)
• Charge Point Details: Every charge point's status, power, and connector type exposed as entity attributes
• Occupancy Tracking: Persistent occupancy histograms by hour-of-day and weekday, accumulating over time and surviving restarts
• Map Integration: GPS coordinates as attributes so the sensor appears on the HA map

Installation

HACS (Recommended)

1. Click the badge above, or go to HACS → Integrations → search for "SmartCharge"
2. Install the integration
3. Restart Home Assistant

Manual

1. Download the integration files into your custom_components directory:

   custom_components/smartcharge/
   

2. Restart Home Assistant

Configuration

1. Go to Settings → Devices & Services
2. Click "Add Integration"
3. Search for "SmartCharge"
4. Choose what to add: a Car (green-charging tracker) or a Charging Station

Adding a Car

5. Enter a Car Name, the Car Device Tracker entity, the Charging Power sensor entity (in kW), an optional Odometer sensor (in km, for per-km stats), and the CO₂ Intensity entity (e.g. from the Electricity Maps integration — auto-selected if found)

Six sensors are created and grouped under a single device named after the car.

To track multiple cars, add the integration once per car.

Adding a Charging Station

Choose from five station types:

Search Nearby Stations (Recommended)

Drag the map pin to your area, adjust the radius, pick a station from the results, and configure the update interval and tariff.

Browse EnBW Map & Enter Station ID

Manually look up a station on the EnBW map and enter its ID.

Find Station at Car's Current Location

Search for an EnBW station at the car's current GPS position. The search expands from 50 m → 100 m → 200 m until a station is found.

Temporary Station (removed after next drive)

Register a one-off charging stop using the car's current GPS position as the station location. The entry is automatically deleted once the car's odometer increases — i.e., after driving away. Requires at least one car entry to be configured.

Custom Wallbox

Add a fixed wallbox at the car's current GPS location. Provide a live price entity (ct/kWh) and optionally a live CO₂ intensity entity (gCO₂/kWh). When a CO₂ entity is provided it takes priority over the car's configured CO₂ entity. Requires at least one car entry to be configured.

Note: Temporary stations and wallboxes create a lightweight config entry with no sensor entities. They exist solely to supply location and tariff data to the car tracker's proximity-billing logic.

Auto-Discovery

When Automatically discover charging stations while charging is enabled in the car options, SmartCharge will search for nearby EnBW stations each time the car starts charging at an unrecognised location. If stations are found, a notification appears in the HA UI prompting you to add the station permanently. Only one discovery attempt is made per charging session.

Car Tracking (Green Charging)

When you add a Car config entry, SmartCharge creates a device grouping six sensors per car. All sensors update together every poll cycle (≈ 5 minutes).

Car Sensors

Sensor	State	Unit	Icon
CO2 Intensity	Live grid CO₂ at the car's GPS location	gCO₂/kWh	mdi:molecule-co2
Accumulated Energy	Total kWh charged (persisted across restarts)	kWh	mdi:ev-station
Accumulated CO2	Total gCO₂ produced for that energy (persisted)	gCO₂	mdi:smog
Accumulated Cost	Total charging cost — proximity billing (persisted)	EUR	mdi:currency-eur
CO2 per km	Average gCO₂ per km driven (requires odometer)	gCO₂/km	mdi:leaf
Cost per km	Average charging cost per km driven	EUR/km	mdi:cash-marker

The CO2 Intensity sensor has no additional attributes. CO₂ and cost accumulators are persisted across restarts.

Cost Billing (Proximity-Based)

When the car is within range of a configured station that has a tariff set, charging costs are billed automatically:

• A base fee (if configured) is added once when a new charging session begins
• A per-kWh cost accrues continuously while charging at that station
• A billing session ends when power drops to zero or the car moves away

For wallboxes, the price is read live from the configured price entity each poll cycle.
For temporary stations, the tariff is fixed at the time of adding.

Updating Car Settings

Use the integration entry → Reconfigure to update the car name, device tracker, power sensor, odometer sensor, CO₂ intensity entity, or auto-discovery toggle. The same settings are also accessible under Configure (Options).

Getting Station IDs (Manual Fallback)

If you prefer to enter a station ID directly, you can find it using your browser's developer tools:

1. Open the EnBW charging map
2. Open your browser's developer tools (press F12), then go to the Network tab
3. Click on a charging station on the map
4. In the Network tab, look for a request to the EnBW API, e.g.:

   https://enbw-emp.azure-api.net/emobility-public-api/api/v1/chargestations/134057
   

5. The number at the end of the URL (e.g. 134057) is the station ID

Tip: You can also find the API subscription key in the request headers under Ocp-Apim-Subscription-Key if you want to set a manual key in the integration options.

Devices

Each config entry creates a device in HA. Going to Settings → Devices & Services → SmartCharge shows a device card per car or station.

• Car device: named after the car name you entered during setup. Independent top-level device.
• SmartCharge hub device: a single parent device created automatically when you add your first charging station.
• Station devices: each station is a child of the SmartCharge hub, named after its static friendly name (e.g. MVV_station_829151). Clicking the hub shows all stations underneath it.

Temporary stations and wallboxes have no associated sensor entities or device card — they are configuration-only entries invisible on the Devices page.

Entities

Car entry (6 sensors per car)

See the Car Tracking section above.

EnBW Station entry (1 sensor per station)

• State: available (at least one charge point is free) or occupied (all charge points in use)
• Dynamic Name: Updates to show availability, e.g. 2 / 5 - Hauptstraße 10, Stuttgart. For stations with more than 9 charge points, the available count is spaced (e.g. 1 0 / 10 - StationName).
• Icon: Switches between mdi:ev-station and mdi:ev-station-unavailable

Attributes

• total_charge_points: Total number of charge points at the station
• available_count: Number of currently available charge points
• occupied_count: Number of currently occupied charge points
• latitude / longitude: GPS coordinates (enables map display)
• address: Physical address
• Per charge point (keyed by EVSE ID): Status, power in kW, and connector type, e.g. available | 50 kW | CCS
• occupancy_weekday: Average occupancy % by day of week (accumulated over time)
• occupancy_hourly: Average occupancy % by hour of day (accumulated over time)

Reconfiguring entries

Entry type	Reconfigure	Options (Configure)
Car	Car name, tracker, power sensor, odometer, CO₂ entity, auto-discovery	CO₂ entity, auto-discovery
EnBW Station	Update interval, friendly name, tariff	Update interval, API key mode, tariff
Wallbox	Price entity, CO₂ entity	Price entity, CO₂ entity
Temporary Station	Tariff price, base fee	Tariff price, base fee

Dashboard: Occupancy Histograms with Plotly Graph Card

You can visualize the occupancy data as color-coded bar charts using the Plotly Graph Card (install via HACS → Frontend).

type: custom:plotly-graph
raw_plotly_config: true
defaults:
  entity:
    type: bar
    showlegend: false
    marker:
      colorscale: Portland
      cmin: 0
      cmax: 100
  xaxes:
    type: category
    showgrid: true
  yaxes:
    range: [0, 100]
    title: Occupancy %
    dtick: 25
    showgrid: true
entities:
  - entity: &station sensor.YOUR_STATION_availability
    name: Hourly
    x: $ex Object.keys(meta.occupancy_hourly || {})
    "y": $ex Object.values(meta.occupancy_hourly || {})
    marker:
      color: $ex Object.values(meta.occupancy_hourly || {})
  - entity: *station
    name: Weekly
    x: $ex Object.keys(meta.occupancy_weekday || {})
    "y": $ex Object.values(meta.occupancy_weekday || {})
    xaxis: x2
    yaxis: y2
    marker:
      color: $ex Object.values(meta.occupancy_weekday || {})
layout:
  title: Station Occupancy
  height: 500
  grid:
    rows: 2
    columns: 1
    subplots: [[xy], [x2y2]]
    roworder: top to bottom
  xaxis:
    dtick: 2

Note: Replace sensor.YOUR_STATION_availability with your actual station entity ID. The YAML anchor (&station / *station) ensures the entity is defined only once. The meta variable provides direct access to the entity's attributes. Bar colors follow a continuous gradient (Portland colorscale) from low (blue) to high (red) occupancy. Other built-in colorscales: Jet, RdYlGn_r, YlOrRd, Viridis — see Plotly colorscales.

Service Calls

Refresh Data

service: smartcharge.refresh_data

Automations Example

Notify when a charge point becomes available

automation:
  - alias: "Notify when charging station available"
    trigger:
      platform: state
      entity_id: sensor.my_station_availability
      to: "available"
    action:
      - service: notify.mobile_app_phone
        data:
          title: "Charging Station Available"
          message: >
            {{ state_attr('sensor.my_station_availability', 'available_count') }}
            charge point(s) now free!

Troubleshooting

No entities created

• Check that your station ID is correct on the EnBW map
• Verify internet connectivity
• Review Home Assistant logs for errors (custom_components.smartcharge)

electricityMap API key errors

If you see electricityMap returned HTTP 401 in the logs, your API key is invalid or expired. Update it via Settings → Devices & Services → SmartCharge → Reconfigure (or Configure) on the car entry. The warning is logged once and then suppressed until the key is updated.

Accumulated stats reset unexpectedly

Energy, CO₂, and cost accumulators are persisted to .storage/smartcharge.car.<entry_id> and survive restarts. If values appear to reset, check that the .storage folder is writable and not excluded from your backup strategy.

Data not updating

• Check the update interval setting in the integration options
• Verify the API is accessible
• Restart the integration

Development

For a local non-Docker approximation of the CI checks, run:

python scripts/validate_local.py

The script validates JSON metadata, checks that strings.json and translations/en.json stay in sync, and runs black --check plus flake8.

For community discussions:

• EnBW Charging Community Thread

License

MIT License - See LICENSE file for details

Support

For issues and feature requests, please open an issue.