Charging an electric car safely at home

A kettle draws a heavy load for three minutes. A car on a portable lead can draw a similar load for ten hours or more, night after night. The Australian Government's EV guidance says a standard power point delivers a maximum of 2.4 kilowatts, and that a full charge that way can take up to 24 hours.

That long, steady load is what finds weak spots. A slightly loose terminal behind the faceplate, or a worn socket that no longer grips the plug firmly, adds resistance, and resistance under load makes heat. An outlet that has run a toaster for years can show its age within weeks of nightly charging.

Plenty of drivers charge this way without trouble. The outlet just needs to be in good condition, on a sound circuit, and checked before it becomes the regular charging spot.

The single most useful habit is plugging the car's lead directly into a wall outlet. The Australian Government's advice, as with any higher-powered home appliance, is to plug the EV charging cable directly into the power point rather than using extension cords or power boards.

Extension leads add joints, and joints are where heat builds. A lead left coiled on a reel traps heat, and household leads are often lighter than the load they end up carrying. Power boards and double adaptors add another plug-and-socket connection, and many aren't made for hours at a heavy load.

If the lead won't reach, that tells you the outlet is in the wrong place. A weatherproof outlet where the car parks, on its own circuit, solves the reach problem and the load problem together.

Get into the habit of touching the plug when you unplug in the morning. Slightly warm can be normal after a night's charge. Too hot to hold comfortably, a smell of hot plastic, or brown marks around the pins or the outlet are not.

If you notice any of those, stop the charge from the car or its app first, then unplug and leave that outlet unused until a licensed electrician has looked at it. Energy Safe Victoria says not to touch or try to repair a loose, cracked or broken power point; cover it and have a licensed electrician replace it.

Many cars let you turn the charging current down from the dashboard or app. It can be a sensible stopgap on an outlet you're unsure of, but it doesn't fix a worn socket or a loose connection. That needs a repair.

Many homes in the newer estates around Point Cook, Tarneit and Werribee park on a driveway or under a carport, so the lead runs outside. Energy Safe Victoria says not to use extension leads or power leads in wet areas unless they're specifically designed for that purpose, and an ordinary indoor outlet on a garage wall isn't made for rain either.

An outdoor outlet should be weatherproof, with a cover that closes over the plug while it's in use, and mounted high enough that splashback and puddles can't reach it. Keep the lead off ground where water pools, out of the mower's path and clear of where a car door or garage door could pinch it.

Feeding the lead through a window or under a door is a common shortcut. It crushes the cable, leaves the plug in the weather and keeps the house open. If the only outlet within reach is inside, it's worth adding one where the car actually parks.

The portable lead supplied with most cars has a control box in the cable that talks to the car and watches for faults. Treat it like a good power tool lead: coil it loosely, hang it up rather than leaving it on the driveway, and keep it off hot concrete on a summer afternoon where you can.

Check it every so often for cuts, crushed sections, cracked plugs and burnt or bent pins. A damaged lead goes out of use until it's replaced. Use the lead that came with the car, or a replacement the car maker approves, rather than a cheap unbranded one.

Energy Safe Victoria says a safety switch is now compulsory on new residential installations, and that it turns the power off within 0.03 of a second when it detects a problem that may put people at risk. If the garage outlet is on an older board without one, sort that out before nightly charging becomes routine.

Sharing matters too. If the outlet shares a circuit with a freezer, a workshop or the laundry, the car adds to whatever else is running. Breakers tripping around dinner time are a sign the circuit, or the whole supply, is being asked for more than it was set up for.

For regular charging, a circuit of its own is the tidy answer: a dedicated weatherproof outlet for the portable lead, or a wall charger. Energy Safe Victoria notes the Wiring Rules call for additional safety switch protection when an installation is altered, and Type AC safety switches can't be installed any more, even like for like.

The Australian Government's EV guidance suggests talking to a licensed electrician about your charging options. In practice, a check makes sense before an outlet becomes the regular charging spot, in an older home, and any time you notice heat, a smell or tripping.

An electrician looks at the outlet and the wiring behind it, what else the circuit feeds, the safety switch, and the switchboard and supply if a wall charger is likely. Fitting an outlet, changing breakers or wiring a charger is licensed work: Energy Safe Victoria says unlicensed electrical work is illegal and potentially fatal, and every job should end with a Certificate of Electrical Safety.