How to charge your electric car at home
Wallbox or smart charger? And how do you install it? We answer popular questions about home EV charging
With more new and used electric cars being sold, increasing numbers of people are wondering how to charge them at home; at least the 60% of those fortunate enough to have a driveway (40% for those living in urban areas).
For these people, for its sheer ease and convenience home charging is very popular with, according to the Energy Saving Trust, 80% of EV charging taking place there.
Another appeal of home charging is that it's cheaper than charging anywhere else, while depending on your energy supplier, it may be even cheaper at night when you don't need your car. You wake up each day effectively with a ‘full tank’ and so are less likely to require a street-side charger on your way to work.
It all sounds straightforward but there are many things to consider when it comes to charging at home, from picking the right type of charger to making sure you're benefiting from the financial incentives available.
Read our guide below for all the advice you need for charging your EV at home.
*How do I charge my electric car at home?*
There are a couple of options when home charging. Most drivers use a wallbox but some plug their car directly into a standard three-pin socket. However, this solution is very slow with many car manufacturers limiting the current drawn directly from a socket to 2.3kW. It means that a car with a typical 64kWh battery, such as the Kia Niro EV, can take more than 24 hours to fully charge. Bigger lithium-ion batteries used in models such as the Tesla Model S or Mercedes EQS can take days. For these reasons, it's not surprising this method is called trickle charging.
For most people, with charging speeds more than three times as fast as a three-pin socket and the convenience of mounting the box directly onto the wall of their house or garage, a wallbox unit is a far better solution. Cables also don’t need to be run into the house through open doors or windows.
*How often do I need to charge my car from home?*
It depends how often you drive, how big your car's battery is, how you charge it and what the outside air temperature is. According to the RAC Foundation, electric cars are driven an average of 26 miles per day. Some early versions of EVs, such as the Nissan Leaf Mk1, have a small battery and so a real-world range of just 80 miles. Even so, with most commuters travelling less than 10 miles to work, even this is sufficient for up to four days of commuting without recharging. However, this assumes the car has been charged to 100% when charging to 80% is the recommended limit for preserving an EV's long-term battery health.
For a longer range with less charging frequency, simply choose an EV with a bigger battery. The average size is 40kWh but 62kWh, such the battery in the VW ID 3, should provide about 250 miles or nine days of average-mileage driving without charging. If your car has a large battery but you charge it only from a three-pin socket, expect its charge level to still be low the next day. A wallbox charger will replenish most batteries to 80% overnight, meaning you won't have to charge again for a few days.
Another factor in determining how often you'll need to charge your car is the ambient temperature. EV batteries perform less well in cold weather and their range can fall by between 10-30%, so expect to charge more frequently, especially in winter.
*What is a wallbox charger?*
A wallbox charger is a stand-alone unit wired directly into your domestic electricity supply. It’s mounted to the external wall of your property and allows you to quickly and easily plug your car in to charge.
You can buy fast charging units that will reduce the time it takes to replenish the battery, as well as ‘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. Other chargers can be linked to solar panels, helping reduce your bills and carbon footprint.
Most wallbox units charge at 7kW, although there are simpler and cheaper chargers that charge at slower speeds of around 3kW.
The biggest caveat for home charging is that you need access to a driveway, garage or some other form of off-street parking close to your house, as you can’t stretch a charging cable across roads or footpaths.
*How much does it cost to install an electric car wallbox charger for home use?*
Prices for home chargers depend on the desired charging speed plus any ‘smart’ features you might be after.
Basic 3kW slow chargers start at around £100, whereas you’ll need around £300 for a faster 7kW unit. ‘Smart’ units that feature wireless control via a smartphone app cost between £450 and £1000.
In general, 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.
Keep an eye on major car manufacturers - some offer a free wallbox and fitting when you purchase one of their EVs.
*What is the wallbox grant?*
To encourage drivers to switch to EVs, 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% 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.
However, as of April 2022 the government changed the eligibility criteria, meaning most homeowners with off-street parking were no longer able to apply for the grant.
Instead, the incentive is now limited to homeowners living in a flat or apartment (provided they also have off-street parking), tenants of rented properties (with the landlord’s permission) and small business owners.
*How do you install a charging point 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, you can choose your own technician but they will need to have accreditation from the manufacturer of your chosen device.
The fitter will probably need to check your preferred location for fitting and your home’s electrical circuitry before going ahead. 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 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% to avoid overheating the cells, so improving their longevity.
Smart chargers cost more to buy than standard units but bear in mind that the government's OZEV subsidy only applies to this kind of equipment, meaning that if you meet the criteria then they actually work out cheaper to buy.
As to whether you need a smart charger, well that’s up to your budget and needs. However, there’s no denying that having one will allow you to make the most of your energy tariff and ensure that your car is always charged and ready when you need it. It costs more to buy but it shouldn’t take long to reap the rewards.
*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 charging time by about half compared with 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. However, if you there are multiple EVs in the household, a 22kW charger will be ideal for sharing.
*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 three-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 three-pin charger as an emergency back-up. It's also worth checking if a cable is included as standard, as certain manufacturers don't include one now due to the increasing size of EV batteries and the subsequent impracticality of charging using this method.
*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 fully charge a car such as a Mini Electric with a 32.6kWh battery 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. However, if you usually charge overnight then the benefits of upgrading your whole domestic wiring system will be negligible.
*How can I check if I 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 a three-phase supply there will be three of these larger system fuses, typically each rated at 100 amps.
*What’s the difference between an untethered or tethered charger?*
The terms simply refer 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. It 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 and which plugs into the charger at one end and the EV at the other. This is a more flexible solution as it allows you to quickly swap between Chademo and CCS 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 and select retail customers, 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 EV owners and users there are financial benefits, with the energy provider paying for the electricity it uses.
The next step is for V2H (vehicle to home) or V2X (vehicle to everything) charging, with your car becoming part of the energy supply to your home or the wider grid. The former 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.
With V2X the benefits are even more far-reaching, albeit some way off yet. Essentially, the set-up would allow you to ‘trade’ energy wherever you park up and plug in. So you could leave your car at the airport parking and receive a discount on parking if the site uses some of the energy in your car’s battery to balance the grid supply at peak times.
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 e-NV200 van. However, various firms are close to being able to deliver similar technology for the more popular CCS charging system, with British company Indra leading the charge.
