Watt Budget Charging calculator

Your electric car in Home Assistant

Battery level, range, charging status: once your car is in Home Assistant, you can time charging around solar or off-peak hours, and Watt Budget reads the level on its own. These guides start from scratch, brand by brand.

Guides by brand

XpengTested

G6 tested; P7+, G9, X9 and L03 probably compatible. WiCAN Pro dongle and the XPENG Direct app, local and subscription-free.

Read the guide →Renault · DaciaNew

Official Home Assistant integration (MyRenault or MyDacia account), no hardware to buy. Charge limits adjustable on recent models.

Read the guide →MGNew

Community SAIC MQTT Gateway (Home Assistant app + MQTT), with a secondary iSMART account so you keep the app on your phone.

Read the guide →ŠkodaIn transition

Free public API opened by Škoda (key created in MyŠkoda) and an official integration expected with Home Assistant 2026.11. The old MySkoda integration is shutting down.

Read the guide →Kia · Hyundai · GenesisNew

Community “Kia Uvo / Hyundai Bluelink” integration (HACS), Kia Connect or Bluelink account. AC and DC charge limits adjustable.

Read the guide →TeslaNew

Three official integrations: Teslemetry (simplest, a few euros a month), Tessie, or Tesla Fleet (free but technical). Real-time data and full commands.

Read the guide →Peugeot · Citroën · DS · OpelNew

Community “Stellantis Vehicles” integration (HACS), with your MyPeugeot, MyCitroën, MyDS or MyOpel account. Preconditioning and charge limit with e-Remote.

Read the guide →Volkswagen · Cupra · SEAT · AudiIn transition

VW Group Connect (HACS) through the EU Data Act portal, after the 2026 lockout. Battery level and charging read-only; commands depend on the brand.

Read the guide →BMW · MiniNew

Official BMW CarData service (continuous data) and the community “BMW CarData” integration (HACS). Replaces the old integration, stopped in 2025.

Read the guide →FordExperimental

marq24's community FordPass integration (HACS), with a separate Ford account. Fetching an access token at setup is tricky.

Read the guide →NissanNew

Community “NissanConnect [EU]” integration (HACS), NissanConnect Services account. Leaf since 2019, Ariya, Micra EV.

Read the guide →VolvoNew

Official Home Assistant integration, with a free API key created on Volvo's developer portal. Preconditioning and locks.

Read the guide →PolestarNew

Community “Polestar API” integration (HACS), log in with your Polestar ID. Read-only, quick setup.

Read the guide →Mercedes-BenzNew

Community “MercedesME 2020” integration (HACS), with a separate Mercedes me account invited to the car. Pre-climate and locks.

Read the guide →BYDExperimental

No reliable cloud access: a WiCAN Pro OBD dongle reads the battery level in the car, locally, with parameters shared by the community.

Read the guide →
Your brand isn’t here yet?

Your car already shows up in Home Assistant and you’d like to share how, or you’re waiting for a guide for your model? Let me know: the next guides will follow requests.

Write via the contact page →

Guides marked “New” were written from each integration’s official documentation and are waiting for their first testers: follow one and tell me what gets stuck.

Next: connect Watt Budget to Home Assistant

Once the battery level is available in Home Assistant, Watt Budget can read it every minute: no more typing the starting percentage, and the calculation takes your home battery and solar surplus into account.

  1. Make Home Assistant reachable over HTTPSWith Nabu Casa or your own domain. Then add the cors_allowed_origins lines to configuration.yaml and restart.
  2. Create a long-lived tokenIn your Home Assistant profile, Security tab. Paste it with the address into Watt Budget: Settings › Home Assistant (shown in expert mode).
  3. Enter your sensorsCar level (one or two sensors), home battery in kWh or %, surplus and Solcast forecast if you have them.
  4. Check“Read now” checks everything; tick “Refresh every minute” for automatic updates.
Direct connection

Watt Budget reads your sensors straight from your browser, on your own Home Assistant.

Open the detailed guide in Watt Budget

What does a charge really cost you? Off-peak tariffs, solar, rapid chargers and XCombo codes: Watt Budget works it all out, free and without an account.

Open Watt Budget