Why Home Charging Speed Matters More Than You Might Think

Most electric car owners do the vast majority of their charging at home. It's cheaper than public rapid charging, it happens while you sleep, and you start most mornings with a comfortably full battery. But the speed at which your car fills up at home shapes everything: how often you plug in, whether you can top up between the school run and a long drive, and whether an off-peak tariff actually saves you money. Understanding the numbers takes the guesswork out of it.

The Three Things That Decide Your Speed

Home charging speed is never a single figure. It's the result of three limits working together, and the slowest one always wins.

• The charge point's output — how much power your wallbox or cable can deliver.
• Your car's onboard charger — the hardware inside the vehicle that converts AC power into DC for the battery. Many cars accept 7 kW on single-phase, some manage 11 kW, and a few reach 22 kW.
• Your home's electrical supply — a standard UK single-phase supply with a 60 to 100 amp fuse comfortably supports a 7 kW charge point. Three-phase supplies are unusual in houses, but where they exist they allow 11 kW or 22 kW.

If you have a 22 kW charge point and a car with a 7 kW onboard charger, you will charge at 7 kW. No cable, app setting or software update changes that.

Charging from a Standard Three-Pin Socket

The humble domestic plug delivers around 2.3 kW — roughly 10 amps at 230 volts. In practice that adds about 7 to 8 miles of range per hour for a typical car using around 3.5 miles per kWh.

For a 60 kWh battery, a full charge from empty takes the best part of 26 hours. That's perfectly workable for a plug-in hybrid or a genuinely low-mileage routine, but it's slow for a pure electric car. Three-pin charging also demands care: sockets aren't designed for hours of continuous load, so use a properly rated outdoor socket on its own circuit, keep the cable untangled, and avoid extension leads altogether.

Dedicated Charge Points: 7 kW and Beyond

A dedicated home charge point is the standard solution, typically delivering 7.4 kW on a single-phase supply — about 25 miles of range per hour. That's roughly three times faster than a three-pin plug, and it takes a 60 kWh battery from empty to full in around eight and a half hours. Overnight, that is plenty for almost everyone.

If your home has a three-phase supply, an 11 kW or 22 kW unit becomes possible, cutting that to about five and a half hours or under three. But check the car first: many models cap AC charging at 7 kW or 11 kW, so the extra capacity may sit unused. Three-phase also usually means higher installation costs and a conversation with your electricity distributor.

Since 2022, new home charge points in Great Britain must meet smart charging standards, meaning they can schedule charging for off-peak windows and help balance demand on the grid. That's a real benefit if you're on a time-of-use tariff.

How Your Battery and State of Charge Affect Things

Battery size matters just as much as charger power. A 40 kWh city car on a 7 kW point refills in under six hours; an 80 kWh family SUV takes closer to eleven. Divide the usable capacity by the charging power to get a realistic estimate, then add a little for conversion losses and cold weather.

Charging also tapers as the battery fills. Below 80% you'll generally see the full rate; above it, the car slows things down to protect the cells. On AC charging the effect is gentler than at a rapid charger, but the last 10% still takes a disproportionate amount of time. Many drivers simply set an 80% limit for daily use and charge to 100% only before a long journey.

Planning Your Routine Around Real Figures

Once you know your numbers, the routine writes itself. A few practical habits make a genuine difference:

• Work in miles per hour, not kilowatts. If your car does 3.5 miles per kWh, a 7 kW point adds around 25 miles an hour. That's far easier to match against a daily commute.
• Use scheduled charging. Set the car or charge point to run during your tariff's cheap window — typically midnight to 5am. Five hours at 7 kW is around 35 kWh, or roughly 120 miles.
• Plug in little and often. Topping up from 50% to 80% takes far less time than a deep recharge and keeps you flexible if plans change.
• Precondition in winter while still plugged in. Warming the cabin on mains power preserves range and costs nothing extra.
• Check your supply before upgrading. A qualified installer will assess your fuse, earthing arrangement and cable route — some properties need an earth rod or a load management device.

Get those fundamentals right and home charging stops being a calculation you run in your head. It becomes quiet background infrastructure: you plug in, you wake up, you drive.