Currently reading: How to charge your electric car at home
Wallbox charger or smart charger? And how do you install your charger once you've chosen it? We answer all your questions about charging your EV at home
Autocar
News
7 mins read
12 May 2021

Around 80 percent of all electric car charging takes place at home, which means it's important to make sure you’ve got the right technology to make plugging in as painless, quick and cost effective as possible. To make the whole process as straightforward as possible we’ve pulled together this guide that will answer all your questions on the different methods of charging.

Are all electric car chargers the same?

There are effectively two options when it comes to home charging - you can either use the slow charger provided with the vehicle or have a wallbox installed. The former uses a standard 3-pin plug to take power from your domestic supply, plus is simple to use and extremely portable. However, with battery sizes increasing all the time these units can take over 24 hours to deliver a full charge and as a result manufacturers recommend they are only for ‘emergency use’. A better bet, especially if you’re committed to everyday EV use, is a wallbox charger. Installed on the side of your house or in a garage, it is capable of delivering faster charging times safely and reliable. It’s also easier to use and doesn’t require numerous cables running from the house.

What is a wallbox charger?

Essentially it’s a standalone charger that’s wired directly into your domestic electricity supply. As the name suggests, it’s mounted to the external wall of your property and allows you to quickly and easily plug your car in to charge. Better still, you can buy fast charging units that will slash the time it takes to replenish the battery, while there are also ‘smart’ units that you can programme remotely to only charge at certain times (such as when your electricity tariff is cheapest) and that can condition the battery to increase its lifespan.

Most wallbox units are fast chargers, delivering electricity at 7kW, although there are simpler and cheaper 3kW slow chargers available.

You’ll require a driveway, garage or some other form of off-street parking close to your house if you want a wallbox, as you can’t stretch the charging lead over a public footpath or road, plus it will need to be installed by a professional electrician.

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How much does it cost to install an electric car home charger?

This depends on your desired charging speed and the ‘smart’ features you want from your charger. Basic 3kW slow chargers start at around £100 or so, while you’ll need around £300 for a faster 7kW unit. ‘Smart’ units that feature wireless control via a smartphone app are anything between £450 and £1,000. On the whole the cost of fitting is included in the price, but there may be an extra charge if significant changes need to be made to your household wiring. Better still, some manufacturers are currently offering a free wallbox and fitting when you purchase one of its EVs, so it’s worth looking at what offers are out there.

What is the wallbox grant?

To encourage drivers to switch to EV, the Government is offering financial incentives through its OZEV (Office of Zero Emissions Vehicles) department. If you buy a new EV, then you’ll currently qualify for a grant that pays for 75 percent of the price and installation cost of a wallbox, up to a maximum of £350. Currently you can apply for a grant for each EV you own, although this is limited to just two vehicles.

How to get an electric car charging point installed at home

The most straightforward way is to arrange the installation through the company selling the wallbox. The price of fitting is often included in the purchase price with the wallbox provider having its own approved installers. If you buy the unit on its own then you can choose your own technician, but they will need to have accreditation from the manufacturer of your chosen device.

It’s worth being aware that the fitter will probably need to check your preferred location for fitting and your home’s electrical circuitry before going ahead. And if you want the wallbox fitted a long way from your fuse box or your wiring needs upgrading, then be prepared to pay a bit more for installation.

What is a smart charger and do I need one?

A smart charger is a wallbox that uses wi-fi or Bluetooth to connect with various apps on your smartphone. In doing so it allows you to remotely tailor your car’s charging schedule, giving you the ability to select when charging happens and how much electricity to put into the battery. As a result, you can make sure you’re only charging when electricity is cheapest, or limit the amount of energy in the battery to 80 percent to avoid overheating the cells and improving longevity. Smart chargers cost more to buy than standard units, but bear in mind that the Government's OLEV subsidy only applies to this kind of equipment, meaning that in most circumstances they actually work out cheaper to buy.

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What wattage wall charger should I buy?

The current that your charger can supply will be based both on your home wiring and your car’s on board charging adaptor. The lowest available is the 3kW slow charger, which even on something like a Nissan Leaf with a modest 40kWh battery will require 12 hours for a full charge, while larger models such as an Audi e-tron will need more than 24 hours.

Most wallboxes deliver 7kW fast charging, which reduces the time by about half compared to 3kW units. Almost all electric cars will be able to charge at this rate, which is ideal for home use when most charging is done overnight.

There are also 11kW and 22kW options, but these require a three-phase power supply, which is rare in domestic applications but often found in industrial or business premises. You can have your home upgraded, but it’s unlikely that the extra cost would justify the quicker charging times.

Can I plug my electric car into a regular socket?

The majority of electric cars come with a portable slow charger that can be used with a 3-pin plug in a domestic power socket. This charges at around 3kW, making it the slowest form of charging, with some larger EVs requiring more than 24 hours for a full charge. Most manufacturers now recommend that you get a wallbox installed for domestic charging, only using the 3-pin charger as an emergency back-up. It's also worth checking a cable is included as standard, as certain manufacturers don't include one.

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How fast can you charge an electric car at home?

In most situations a 7kW fast charging wallbox offers the quickest method of charging at home. With this unit you can expect to full charge something like a MINI Electric in as little as three and a half hours, while a Nissan Leaf 40kWh will take closer to six hours.

For even faster charging you’ll need to upgrade your wiring to a three-phase system (domestic wiring is usually single-phase), which will allow 22kW charging. At this rate a Nissan Leaf with a 40kWh battery can be fully charged in as little as two hours.

How to check if you have a three-phase connection?

The best way to check whether your property has a three-phase electrical supply is to get a qualified electrical engineer to assess your home’s wiring. However, sometimes a quick visual inspection can reveal whether further investigation is necessary. Normally the best way is to locate your fuse box and meter, as this is where the electricity supply enters the house. With a single phase supply there will usually be a single large system fuse alongside the meter and fuse box containing circuit breakers for the various areas and appliances of the house. In three-phase supply there will be three of these larger system fuses, typically each rated at 100amps.

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What’s the difference between an untethered or tethered charger?

This simply refers to the type of charging cable attached to the wallbox. A tethered unit features a permanently attached cable with either a Type 1 or Type 2 connector, and is the perfect choice if you have just one EV as it makes for simple charging - simply park-up and plug in.

With untethered units you use the charging cable provided with the car, which plugs into the charger at one end and EV at the other. This is a more flexible solution as it allows you to quickly swap between Type 1 and Type 2 cables if, say, you run two different EV models with different connectors, such as a Nissan Leaf and a Peugeot e-208.

What is Vehicle to grid (V2G)?

Currently only available to businesses, V2G (Vehicle to Grid) charging effectively integrates an EV with the national grid. When a number of vehicles are connected for long periods at dedicated V2G chargers (such as when parked up during the day while their owners are at work, or overnight), energy providers can use the combined capacity of the batteries for energy storage or access their electricity for extra power during peak periods. For businesses there are financial benefits, with the energy provider paying for the electricity it uses.

The next step is to roll out the technology into a domestic environment, with your car becoming part of your home’s energy supply. This system could prove particularly useful with renewable energy, allowing you to store electricity generated by solar or wind power that would otherwise go to waste, such as during the day when there’s less need for heating and lighting. The only downside is that currently only vehicles fitted with the CHAdeMO charging connector are capable of this two-way flow of energy. That effectively means only models from Nissan, such as the Leaf and EV200 van.

READ MORE

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Comments
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superstevie 12 May 2021

Dear AutiCar, do you know what would be a really useful article for millions of motorists? How someone who doesn't have a house with a driveway can get on with charging an electric car. I'm in Edinburgh, and the average home here is a 2 bedroom flat, which means very little chance to have a wall mounted box. All these sorts of articles, and electric car reviews, focus on being able to charge at home, when a large portion of the driving population do not have this facility. 

Also, it could look at which cities (outside of London and the south east) do well with public chargers. Edinburgh is dreadful, with very few.

Halcyon 23 December 2020

"For even faster charging you’ll need to upgrade your wiring to a three-phase system (domestic wiring is usually single-phase), which will allow 22kW charging. At this rate a Nissan Leaf with a 40kWh battery can be fully charged in as little as two hours."

Autocar, this is not true! Nissan Leaf can AC charge only at 7 kW. You can take full advantage of the 22 kW wall charger only if the car supports charging at that rate and very few cars do. Most EVs are limited either to 7 kW (single-phase) or 11 kW (three-phase) charging. Only a handful of EVs, such as Renault Zoe can charge at 22 kW (three-phase).

Especially the 7 kW (single-phase) charging sucks. Outside UK, most European countries have three-phase domestic network connections, the main fuses are typically 3x25 A (most common) or 3x35 A. The 7.4 kW single-phase charger draws 32 Amps of current, and as you can see this is too much for the typical three-phase domestic network connection. 11 kW three-phase charger is better because it draws 16 Amps of current from all three phases and can be used in all houses with three-phase connection (if there is not too much other load). This is the reason I will never buy an EV with 7.4 kW single-phase charger, because with that I would be stuck charging at a measly rate of about 3 kW (I don't live in UK).

Rods 17 December 2020

Interesting article. Silly question: How are these wallboxes secured? For example, suppose I'm away at work most days with no car outside my house, could I lock the wallbox?If not, what's to stop some other electric car driver who realises my schedule from parking outside and nicking my energy while I'm out?