Single phase gives you 7kW, which fully charges most EVs overnight. 22kW needs three-phase supply and suits two-car homes, workplaces and fleets. The real difference, what a supply upgrade costs, and when load management and OCPP matter.
The choice between a 7kW and a 22kW EV charger is really a choice about your power supply and how you drive. Most homes are well served by 7kW. A few genuinely need 22kW, and those few pay for three-phase power to get it. This guide draws the line clearly, prices the supply upgrade, and covers two features that protect you regardless of rate: load management and OCPP.
A 7kW charger runs on the single-phase supply most Hunter homes already have. It adds roughly 40 to 50km of range per hour, which means a full charge overnight for almost any EV. Unless you are driving several hundred kilometres a day and turning the car around in a few hours, 7kW covers you. The maths is simple: an empty battery and eight hours of overnight charging is more than enough headway. Paying for a faster rate you never use is money spent to solve a problem you do not have.
22kW needs three-phase power and earns its place where vehicles share a charger or need a fast daytime top-up. Two-car households that both charge nightly, workplaces with staff vehicles, and fleets that turn over during the day are the real candidates. The deciding question is whether you can wait for an overnight charge. If you can, 7kW wins. If you cannot, 22kW is worth the supply work.
Going to 22kW usually means upgrading your supply to three phase, which runs $3,000 to $8,000 depending on how close your street and board are to three-phase infrastructure. That can cost more than the charger. An honest quote prices the supply upgrade as its own line so you can weigh it against the benefit. Before any of this, your board has to be checked. See will my switchboard take an EV charger for the four checks that come first.
We price the supply upgrade and the load management as separate lines, and we fit OCPP chargers. The cheap quote sells you a rate and lets the three-phase surprise land mid-job.
Two features matter more than raw kilowatts. Load management lets the charger throttle itself when the rest of your home is drawing heavily, which can avoid a supply upgrade entirely by sharing capacity intelligently. OCPP is an open protocol that keeps your charger compatible with different management software, so you are not locked to one vendor who can change terms or disappear. For workplaces and fleets especially, insist on OCPP. And if you have solar, ask about solar-smart charging, which times the charge to your generation so you fill the car on your own power rather than from the grid.
Most homes should buy 7kW, add load management, and charge on solar where they can. Buy 22kW only when a real need for fast turnaround justifies the three-phase cost. Either way, demand an OCPP charger so the decision stays yours.