Most NZ homes are on a single-phase 60–80 A supply. The fastest a single-phase home charger can run is 7.4 kW (32 A). To get 22 kW you need a three-phase board upgrade — typically $3,000–$8,000 of switchboard and supply work.
What 7 kW gives you
- ~40 km of range per hour of charging
- Empty to full overnight on most EVs
- Off-peak charging (11pm–7am) at half the day rate on most plans
The average NZ EV driver does 40 km/day. So you're replacing ONE hour of charge each night. A 22 kW charger doesn't help — your car can't take it.
When 22 kW is justified
- You drive 200+ km/day for work
- You have multiple EVs sharing one charger
- You're already upgrading to three-phase for other reasons (heat pump pool, induction range, etc.)
Get a registered electrician to check your supply before you buy a charger. Most "smart 22 kW" units sold online won't actually run at 22 kW from a single-phase board.