Vehicle Charging During Power Outage

Powerwall coordinates with Tesla vehicles for enhanced vehicle charging during a power outage without exceeding the energy and power capabilities of your Powerwall. Additionally, Powerwall continuously responds to the changing power needs of your home and will slow or stop your vehicle's charging to keep your home loads powered.

Note: Charging during a power outage will not affect the overall life of Powerwall or your vehicle’s battery.

How It Works

When a power outage occurs, Powerwall will charge your Tesla vehicle based on your charging threshold. Your charging threshold determines how much power you want Powerwall to share with your vehicle. To set the charging threshold, tap ‘Settings’ on the home screen of your Tesla app and adjust the slider. Once your Powerwall’s stored energy level is less than your threshold, Powerwall stops charging your vehicle and continues to provide backup power to your home. If charging stops, you’ll be able to resume charging your vehicle by doing one of the following:

  • Lower your charging threshold
  • Waiting for the power outage to end
  • Waiting for solar to recharge your Powerwall above your set threshold

Solar Integration

If your home is equipped with solar and your vehicle is plugged in and charging while the sun is shining, Powerwall will continue to share any excess solar with your vehicle after Powerwall discharges to your set threshold. Powerwall’s stored energy will remain at your set threshold as long as there is excess solar available. When there is no longer excess solar available, Powerwall will automatically stop charging your vehicle and prioritise powering your home.

When your Powerwall has fully charged, solar production will stop. By sharing excess solar with your vehicle, your solar system can continue to produce energy and help you maximise the value of your solar installation, even during a power outage.

Detailed Charging Behaviour

Depending on what appliances you are running during a power outage, you may notice that your Powerwall slows down charging your vehicle. This is done to prioritise powering your home. Your Tesla vehicle will display a status message on the touchscreen if Powerwall slows or stops your vehicle charging session. Vehicle charging may not automatically restart if charging stops. View how charging behaviour varies during an outage:

Power State Home Electric Loads Charging Behaviour
On grid Any loads Vehicle charges as normal
Power outage with Powerwall above energy threshold (or optionally with excess solar) Low loads Vehicle charges with excess power and energy
High loads Vehicle slows charging to prioritise your home loads
Power outage with Powerwall below energy threshold Any loads Vehicle stops charging

Compatible Home and Vehicle Configurations

This coordinated charging feature is available for Tesla vehicles using a Tesla home charging solution, including Wall Connector and Mobile Connector. Your charging connector must be on a circuit backed up by Powerwall. If your Powerwall does not provide whole home backup, your charging connector should be located on your essential loads sub panel to support charging during a power outage.

Note: No internet connection is necessary to support this charging feature.

Supported Versions

  • Powerwall: 1.46+
  • Tesla Mobile App: 3.10.2+
  • All Tesla Vehicles: 2020.40
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