How to charge an electric car

For decades, fuelling your petrol or diesel car was as simple as arriving at the pumps, choosing the right coloured nozzle and squeezing the trigger. As we enter the era of the electric car, that’s all changed – but the good news is that it’s easier than you might think.

In this guide, we’ll outline when, where and how to charge your electric car, and we’ll explode some of the myths around charging.

How to charge a car at home

Charging your electric car is barely any harder than charging your smartphone, but it's made even more convenient if you have a home charger. These cost upwards of £1000, but allow you to charge faster than if you used a household three-pin socket, and mean you can simply pull up on your driveway and start to charge within seconds. Don't know where to start? Check our reviews of the best home EV chargers.

- If you have a home wallbox, pull up as close as you can to it, bearing in mind which side the car’s charging port is
- If you’re charging from a standard household three-pin socket, park as close as you’re able to the plug socket
- Open the car’s charging flap – this is usually the same as opening a car’s fuel-filler flap
- If you have an untethered charger (one which doesn’t have a cable permanently attached), grab your car’s charging cable and plug it into both the charger and the car
- If you have a tethered charger (one which does have a cable permanently attached), you need only connect it to the car
- Unless you’ve set a scheduled charge, or you’re using a smart charger which is automatically set to charge during off-peak hours, the car should start to charge automatically
- Once the car is fully charged, it won’t draw any more electricity, so don’t feel the need to run out in your dressing gown to unplug it in the middle of the night

Note: Most electric cars will come with a Type 2 cable supplied, ensuring you're ready for a home wallbox. It's likely you'll have to pay extra for a cable with a three-pin plug.

How long does it take to charge an electric car at home?

The majority of electric car drivers who have off-street parking will have a home EV charger installed. Typically these deliver a charging rate of 7kW (kilowatts), although some are slower – but if you have three-phase power (don’t worry, because most homes don’t), you could enjoy up to 22kW.

So, what does that tangibly mean? Charging a 55kWh Volkswagen ID3 from flat to full will take:

- 7 hours and 55 minutes at 7kW
- 5 hours and 10 minutes at 11kW
- 2 hours and 30 minutes at 22kW

But if you don’t have a wallbox, all is not lost, because you can use a three-pin EV charger – sometimes called a ‘granny’ charger for their usefulness if you’re spending a weekend at your wallboxless grandparents’ house. These, as their name suggests, have a three-pin household plug, allowing you to charge. However, so connected, you’ll receive no more than 2.3kW, meaning our ID 3 would take a glacial 30 hours to fully charge. That means a granny charger is really only of any use as a last resort.

The key things to remember about the time it takes to charge to charge a car are:

- The size of the battery (expressed in kWh – kilowatt hours)
- The maximum rate of charge (expressed in kW – kilowatts)

To calculate the time it’ll take to charge from flat to full, divide your car’s battery capacity by the charging rate. Although a word of caution: the total battery capacity in your car’s manual is probably slightly more than the capacity you can actually use. This is called ‘usable capacity’.

How to use a public electric car charger

Fundamentally, using a public EV charger is little different than your home charger, but there are a few more steps:

- Pull up alongside the charger
- Connect the charger to your car
- If you have an account with the charging network provider, you’ll need to authorise and start the charge via an app, which are usually specific to each network. If you don’t have an account, you’ll be able to tap your contactless card.
- You’ll be able to track the amount of electricity and the cost via a screen on the charger or on your car’s own screens
- Keep an eye on the charge level. Once you’ve reached the charge level you need, you’ll have to stop the charging via the app or the charger, else it’ll keep charging until the battery is full – which could be an expensive exercise
- If you’re using the app, you’ll be able to generate a receipt. If not, you may have to note the time and date, the amount of charge you’ve taken and the cost and contact the charging network operator directly

Top tip: Because public charging can be up to ten times more expensive than off-peak home charging, only use public charging for the power you need to get home.

How long does it take to charge an electric car using a public charger? 

If you’re preparing to take the plunge and go electric, this is one of the key questions you’ll want answering – and be prepared to have other people ask you the same. 

The short answer is: it depends.

Generally speaking, public chargers range from 50kW up to 350kW, so the faster the charger’s rate, the quicker your car will charge – but no charger will exceed the maximum rate a car can accept. The basic Volkswagen ID 3 we’ve been using in our examples can charge at 120kW. Plug it into a 50kW charger and you’ll get no more than 50kW, but plug it into a 350kW and the car will limit the charge to 120kW.

But that still doesn't mean the ID 3 will charge at 120kW for the whole time it’s plugged in. That’s because every battery has a charging curve which throttles the amount of power it can accept to protect the battery. It means many batteries will charge slowly from around 0-10%, faster around 10-50%, then tail off beyond 80%. 

It’s not just cars that do this: smartphones also take longer to charge from 80-100% than they do from, say, 40-60%. And like smartphones, it’s better for the battery’s long-term health if you don’t repeatedly charge beyond 80%.

This is also why car manufacturers generally quote their charging times from 10-80% charge.

So then, rapid charge times. On a 10-80% charge, our VW ID3 will take:

- 50 minutes at 50kW
- 26 minutes at 150kW

In both cases, it will take a further 15 minutes to charge from 80-100%, which highlights the significance of the charging curve.

Oh, and there's an increase in the number of lamp post chargers, too. These effectively take their power from the feed supplied to power the street lamp, providing a quick and easy solution for the UK to roll out more chargers. However, bear in mind that these deliver speeds of around 7kW — the same as you'd expect from a home wallbox — so are best considered overnight chargers. Just make sure you move your car once your battery is full, to allow others to use it.

Top tip: Many cars have a pre-conditioning function which gets the battery to the optimum temperature to achieve the fastest charge. This can be done manually, or automatically if you plot a charging stop using your car’s ‘native’ sat-nav system. As useful as Apple Maps, Google Maps or Waze are, when displayed through your car’s infotainment system, they won’t trigger the pre-conditioning.

When to charge your car

Like filling up a petrol or diesel car, you can charge your electric car whenever you like, but because even the fastest chargers can take a while, it’s always best to plan a bit ahead. If you’re leaving at 6am, for example, it’s best to ensure the car is charged the night before.

If you’re charging at home, we recommend you consider a dual-rate tariff, or even better, an EV electricity tariff. These will allow you to charge overnight at significantly less than it’d cost during the daytime. Some cars allow you to schedule charging during these hours of low demand, but the apps provided by some electricity companies, such as Octopus Energy, can do this all for you. You simply plug in when you get home, and the software will automatically start charging when electricity is at its cheapest.

The benefits of doing this are huge. Charging a standard range Kia EV3 from flat to full at the current electricity price cap of 27.03p per kWh (kilowatt-hour, the standard measurement unit of electricity) will cost you £14.86. At the 7p per kWh you’ll pay using Octopus Energy’s Intelligent Go tariff, the same charge will cost £3.85.

Like a petrol or diesel car, you can plug your car in regardless of the level of charge. But remember that while your car will accept power from your slower home charger at a relatively consistent rate, the makeup of the batteries means that the rate of faster public chargers will tail off as you pass 80%. That’s why most car makers measure their fastest charge times against a 10-80% charge.

How to find an EV charger

It’s an odd thing, but as soon as you have an electric car, you start noticing public chargers around you and on your routes. And as you start to use them, you’ll quickly know which you can rely on, and which you can't. 

Every year, we run down the list of the best public charging networks based on feedback from thousands of electric car drivers.

But if you’re travelling a long distance – heading on holiday for example – it pays to plan ahead and choose your charging stops on your route. Zap-Map is a website and smartphone app which lists every charger in the country, and allows you to search by charging speed and network operator. It can give you an indication of whether it’s in operation, too. 

And if your car has Android Auto or Apple Carplay, you can access this information via your car’s infotainment system if you pay Zap-Map for the premium version.

Many cars have navigation systems which are able to plot charging stops on your route, and some are able to do this dynamically based on the level of charge at any given point.

Different types of EV plugs

It’s a myth that there are lots of different types of EV plugs. Indeed there are more types of mobile phone chargers than types of plugs used with the latest batch of new electric cars.

Let’s take a look.

Type 2

Type 2 is the standard for home charging in the UK, and can support AC charging up to 22kW.

The plug has seven pins, and a flat side which prevents it being plugged in the wrong way. It’s ubiquitous, and you might consider it the USB of the electric car world.

Note: the Tesla Supercharger network can provide up to 150kW through a Type 2 socket, but is the only technology to do so.

CCS

CCS, or Combined Charging System to give its full name is very clever. That’s because it uses the same Type 2 plug, but adds an extra pair of pins to allow it to accept a much faster DC charge. The fastest chargers currently available are rated at 350kW, and use the CCS standard.

The beauty of CCS is that it can use the same basic socket as a Type 2; all you need to do is ping off an extra cover to access the entire port.

CHAdeMO

You might view CHAdeMO as Betamax – a technology which was there at the start of the EV revolution, but has since fallen by the wayside. The main cars to use CHAdeMO were the original Nissan Leaf and the Mitsubishi Outlander PHEV. It’s not the standard used by any new electric cars.

EV charging FAQs

Can I charge at work?

Many companies now have charging points outside their offices. And even if yours doesn’t, it could apply to the Workplace Charging Scheme (WCS). This is a voucher-based grant that covers 75% of the cost of both the purchase and installation of car charging points.

Criteria for eligibility includes being a business, charity or public sector organisation that is located in England, Wales, Scotland or Northern Ireland.

To apply, you must explain the need for electric car charging equipment and have dedicated off-street parking. Plus, you must be the owner of the property or have consent from the landlord for a charging point to be installed.

You can find the full criteria along with further information on applying for a WCS on the gov.uk website.

Why do car makers quote 10-80% fast charges?

Every electric car has something called a charging curve which determines the rate of charge a car can accept at any given time. Like your smartphone, cars tend to charge fastest when they’re not quite empty and not quite full. This is largely done to protect the battery, avoid excessive heat and to preserve the longevity of the battery.

So that 10-80% figure is a good indicator of how long you’ll be stopped for if you want to get the most amount of charge into your battery in the more economical amount of time.

Can I charge my electric car in the rain?

Yes, it’s perfectly safe to charge your EV in the rain. The cable, wallbox and charge port on the car are sealed from moisture.

Can I charge my electric car from a three-pin plug?

If you use the correct three-pin charging cable, you can charge from a three-pin socket safely. Two things to remember, though: the charge rate will be as slow as it gets, and could take more than a day to charge a car from flat to full. And if you’re running the cable out through windows or doors, ensure the property is secured, and there is no risk of damaging the cable.

Can I charge my EV using an extension lead?

Yes, you can use an extension lead to charge an EV, but it’s not recommended. That’s because ordinary extension cables aren’t designed to handle the sustained high current needed to charge an electric car. That raises the likelihood of overheating and potentially causing electrical fires.

That risk is compounded when you consider that the slow charging speeds you’ll get from a three-pin socket makes it more likely that the extension lead will be unattended.

Rapid charging vs fast charging – what’s the difference?

Rapid chargers are the public chargers which you can expect to receive a decent slug of power quickly; the chargers you’ll want to seek out when you’re on a long journey.

Fast chargers are rather misleadingly named, because they’re not all that fast. Indeed, it refers to the 7kW charge rate most of us will get charging at home using a home wallbox.

AC vs DC

It might sound like a rock band, but AC and DC are two different kinds of electrical current. AC – alternating current – is the current that will be supplied to your house, but it needs to be converted into DC – direct current – by the car. AC charging rates are slower.

If you use a faster public charger, you’ll be using DC current, which has already been converted, hence it’ll charge your car faster.

How much does it cost to charge an electric car?

One of the big incentives for purchasing an electric car is the promise of cheaper running costs than you’d have with a petrol or diesel-engined model. However, while you will save money if you charge at home, there’s a good chance you won’t if you rely on public rapid chargers.

A What Car? investigation revealed that the UK’s fastest EV chargers can cost as much as seven times more than charging at home overnight; some home wallboxes can automatically begin charging once electricity is at its cheapest. 

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