Skip to main content

Can I charge my EV from my battery in a blackout?

Short answer. Sometimes, but it is usually switched off on purpose. An EV charger can draw several kilowatts, enough to drain a battery fast, so on our installs the charger is often left off the backup circuits unless you ask for it. Some brands manage it automatically; Tesla’s Powerwall slows or stops vehicle charging to protect your home loads.

Safety first. Never open a switchboard, remove a cover from your battery or inverter, or touch any wiring. Anything beyond the app, a light you can read from a safe distance, or your own router is a job for a licensed electrician. If you see smoke, smell burning, hear arcing or see water on or near the unit: keep everyone away, switch off at your main switch only if it is safe to do so, and call 000 if there is any fire or smoke.

Why chargers are often left off backup

Our typical install backs up the whole home unless you ask us to leave some circuits out, and an EV charger is the usual exception. The reason is simple: a charger is a big load, and a battery has a limited amount of energy and a limit on power. See whole home vs essential circuits.

What Tesla does

Tesla says Powerwall coordinates with Tesla vehicles on a Tesla home charger, Wall Connector or Mobile Connector, so charging during an outage does not exceed the Powerwall’s energy and power. The charger must be on a circuit backed up by the Powerwall. You set a threshold; while the Powerwall is above it, the car charges, slowing if the house needs power, and once below it, charging stops and the house keeps its backup. Tesla notes no internet connection is needed for this.

Other brands

For Sigenergy, GoodWe, Sungrow and SolaX, whether the charger is backed up is a design decision. If you want it, tell us at the site visit and we will say honestly what it will do to your backup time. See how long will my battery run my house?.

If your charger is backed up

  • Charge only what you need, not to full.
  • Check the battery level first in the app.
  • Expect a long charge to flatten the battery quickly.

We install home EV chargers: home EV charger installation and EV chargers.

When to call us

If we installed your system, call us on 0483 903 020. Our service help for existing customers is free: we start by working through it with you by phone. If you are not yet a customer, a service call is $250 + GST, which covers one hour on site within 20 km of Mullumbimby; travel further out is quoted separately. Contact us or call 0483 903 020 (Mon-Fri 7am-6pm, Sat 7am-4pm). We do not repair systems we did not install.

Quick questions

Will my EV charger work in a blackout?

Only if it is on a backed-up circuit. Many installs leave it off on purpose to save the battery for the house.

Can I add the charger to my backup later?

Often yes, but it depends on your system and its power limit. Ask us.

Does Powerwall charge a Tesla in an outage?

Yes, if the charger is on a backed-up circuit; Tesla says it slows or stops charging to protect your home loads.

Can my car power my house?

Only with specific vehicle-to-home equipment. Ask us before buying.

Sources

Last checked 7 October 2026. Only the manufacturer’s, the network’s or the government’s own documents are used; app menus and defaults change between models and versions, so if your screen looks different, call us rather than guess.

Related guides

Check Your Battery Rebate & 0% Loan