EV Charger Installation at Home: Load, Wiring and What It Costs

A home EV charger turns an overnight park into a full battery, and it is far cheaper per kilometre than public charging. But a wallbox is not a big appliance you plug in, it is a dedicated high-current circuit that runs at close to its limit for hours at a time, and that changes what your home's wiring and switchboard need to handle. Here is what actually goes into a compliant home install, and what it costs.

Single phase or three phase

Most Australian homes are single phase, and a single-phase wallbox charges at up to 7kW, drawing around 32A. That adds roughly 40 to 50km of range per hour, which comfortably fills most cars overnight. Homes with a three-phase supply can run a 22kW charger drawing 32A per phase, charging much faster, though many cars accept less than 22kW on AC so the real-world gain depends on the vehicle.

The key point is that a 7kW charger is a serious sustained load. A kettle pulls 10A for two minutes. A wallbox pulls 32A for six hours. Your wiring, protection and supply have to be sized for continuous duty, not a quick burst.

Your switchboard is usually the deciding factor

Before anything else, the electrician looks at your switchboard and your incoming supply. The charger needs its own dedicated circuit with correct overcurrent protection, and there has to be somewhere to land it. On a full or old board, that means work first. If your board still runs ceramic fuses or has no spare ways, budget for a switchboard upgrade as part of the project. In some cases the total household load with a charger added exceeds what the existing single-phase supply can deliver, and a supply or three-phase upgrade through your network provider becomes necessary.

The RCD type matters here

EV charging has a specific safety requirement that ordinary circuits do not. EV chargers can produce smooth DC leakage under fault, and a standard Type AC RCD can be "blinded" by it and fail to trip. So the circuit must have appropriate protection: either a Type B RCD, or a Type A RCD combined with a charger that has built-in 6mA DC fault detection (many wallboxes include this). This is not a detail to leave to chance, and it is one reason the job belongs with an electrician who installs chargers regularly rather than a generalist. If you want the background on why the device type is the whole game, RCD, RCBO and circuit breaker explained is worth a read.

Load management, so you do not trip the main

If your supply cannot comfortably run a full-speed charger alongside an oven, ducted air conditioning and everything else, the answer is not always a supply upgrade. Many wallboxes support dynamic load management, using a current sensor at the main to throttle the charger down when the rest of the house is drawing heavily, then back up when demand drops. This lets a modest supply live with a charger safely, and it is far cheaper than upgrading the mains. Ask your electrician whether your setup needs it.

Tethered or socketed, and where to put it

Two practical choices shape how much you like the charger years later. A tethered unit has the lead permanently attached, which is convenient day to day but ties you to that connector and leaves a heavy cable to hang up. A socketed unit takes your own Type 2 lead, keeps the wall unit tidier, and is easier to live with if the household ends up running two different cars.

Position matters as much as the hardware. Mount it so the lead reaches the car's port without crossing a walkway, allow for parking nose-in one day and reversing in the next, and think about a second car later. Outdoors, the unit needs a suitable IP rating and is far happier out of direct afternoon sun. Every extra metre from the switchboard adds cable cost, so a garage wall backing onto the board is the cheapest install you will ever get.

Smart features worth having

If the unit is going on the wall for a decade, the features that earn their keep are scheduling, so charging follows an off-peak window or your solar export; per-session energy reporting, which matters if you claim work travel or share the charger; OCPP support, so the unit can talk to third-party software rather than only the manufacturer's app; and firmware updates that do not require a service call. Solar diversion, where the charger uses surplus generation rather than importing, is the feature owners with a PV system consistently say they would not give up.

What it costs

For a standard single-phase 7kW wallbox with a short, tidy cable run to a board that has capacity, a typical installed cost sits around 1,000 to 2,500 dollars including the install but on top of the charger hardware. The number rises with:

• Long cable runs from the board to the garage or carport.
• Switchboard upgrades or a new dedicated circuit.
• Three-phase installs and 22kW chargers.
• Supply upgrades through the network, which are the expensive end.

As always, get itemised quotes so you can see what is hardware, what is labour and what is board work.

Compliance: licensed work, no exceptions

Installing a fixed EV charger is fixed electrical wiring work. In Australia it must be carried out by a licensed electrician, who will install it to AS/NZS 3000 and the EV-specific standard AS/NZS 61851, test it, and issue a certificate of compliance. Portable EV cables that plug into a standard socket exist, but they are limited, draw a lot through an ordinary outlet for a long time, and are not a substitute for a properly installed wallbox. Do not attempt to wire in your own charger.

Choose an installer with EV experience and verify their licence first using our guide to hiring a licensed electrician. If you are supplying your own wallbox or sourcing a used one, check current listings, and note that any second-hand protective device on the circuit must be tested before it is energised, per the AS/NZS 3000 wiring rules for buyers. When you upgrade your charger later, you can sell the old one to another EV owner.

Done properly, home charging is the quiet luxury of EV ownership. The trick is treating the install as the electrical project it is, sizing the supply and protection correctly the first time.