Works with · Solar & battery

Charge your EV on excess solar with Tesla Powerwall

Connect your Tesla energy site and SundialEV reads solar, grid and Powerwall power and charge level, then sends surplus to your car. You decide how full the Powerwall gets before the car takes surplus.

See the setup Estimate your savings
Setup

Four steps, no new hardware

  1. Sign in with Tesla
    The same Tesla sign-in covers your car and your energy site.
  2. Confirm the Powerwall
    SundialEV finds the site and maps its solar, grid and battery readings.
  3. Set your Powerwall priority
    Choose the charge level the Powerwall reaches before solar goes to the car (95% by default). Optionally, hold the Powerwall in Self-Powered mode while the car charges.
  4. Plug in
    Surplus beyond what the house and Powerwall take goes to the car.
SundialEV device setup, solar step: Tesla Powerwall connected, SolarEdge and Enphase ready to connect
The solar step of setup
SundialEV settings: avoid-hours, sell solar at peak rates, and Powerwall charging priority
Powerwall priority, avoid-hours and sell-at-peak
What it reads

What Tesla Powerwall gives SundialEV, and its limits

Provides

  • Solar production
  • Grid import and export
  • Powerwall power and charge level

Known limits

  • Solar-surplus charging waits until the Powerwall reaches your priority level.
  • Sites without a grid meter report a placeholder grid value; SundialEV detects it and estimates surplus from solar minus your baseline household use instead.

What would charging on surplus save you?

Enter your zip and the calculator uses your utility's real rates.

FAQ

Frequently asked questions

Can I keep the Powerwall charged before the car takes solar?
Yes. Powerwall charging priority sets the level the Powerwall reaches first; after that, surplus goes to the car.
Does it work with Tesla Solar and no Powerwall?
Yes. A solar-only Tesla site works the same way, just without the battery settings.
How is this different from Tesla's Charge on Solar?
Charge on Solar requires a Powerwall and only charges Teslas. SundialEV also tracks savings against your utility's rates and can pause solar charging during a sell-at-peak window. Full comparison.

Put your surplus in the car

Connect Tesla Powerwall in a few minutes.

Get started on web Estimate your savings →