Single-Phase vs Three-Phase EV Charging at Home

What's the difference?

Most Australian homes have single-phase power: one "lane" of electricity. Some, often newer or larger homes, have three-phase: three lanes. A three-phase charger can use all three at once.

Your car decides the real speed

Delivered power is the lowest of three things: the charger's rating, what your supply can provide, and the car's maximum AC charge rate.

• A car limited to 7 kW AC charges at about 7 kW on any charger.
• A car limited to 11 kW AC charges at up to 11 kW on a three-phase 11 kW or 22 kW charger — not 22 kW.
• Only some cars accept 22 kW AC. Don't assume yours does; check the manufacturer's specifications.

Worked example (assumptions shown)

Assumptions: you drive 50 km a day, the car uses about 0.17 kWh per km, and about 10% of energy is lost while charging.

• Energy needed: 50 × 0.17 ÷ 0.9 ≈ 9.4 kWh per day.
• At 7 kW: 9.4 ÷ 7 ≈ 1 hour 20 minutes.
• At 11 kW (if your car and supply allow): ≈ 50 minutes.

Either finishes easily overnight. A full charge of a large battery takes longer — that's the scenario where higher power matters more.

When an upgrade may be worth discussing

• Your car accepts 11 kW or more and you regularly need big top-ups quickly.
• Two EVs share the home and both drive long distances.
• An electrician finds your single-phase supply is already heavily used.

Converting to three-phase involves your network provider and can be costly, so get advice before committing. Load management is often a cheaper alternative — see switchboard upgrades.

Frequently asked questions