How to charge an electric car

All you need to know about EV charging

The days of green and black pumps are over, so get ready to plug in and embrace kilowatt hours rather than litres and gallons as we learn how to charge an electric car. To keep your EV moving, you’ll need to make sure your lithium-ion battery is topped up just like your smartphone or laptop.

Fortunately, the actual process of charging an EV is simple. Plug in the cable to your car, wait for the charge to start, and leave it for anywhere between 30 minutes and several hours depending on the charger… more on that in a minute.

There are plenty of other factors that you need to consider, too, for example finding an EV charger, checking the charger has the right connector and getting the best price for your energy.

Our complete electric car charging guide will take you on a step-by-step journey to completely understand how to charge your EV, from how charging works to how long charging an EV takes and how much electric car charging costs.

Types of electric car chargers explained

Depending on where you charge, whether it’s at home, motorway service stations, GRIDSERVE Electric Forecourts®, retail parks, shopping centres or work, you’ll come across a range of different electric car charging points.

While they’ll all work in mostly the same way, the main difference will be the power capability – that’s to say the speed at which they can charge your car.

Some chargers might also have different connectors (more on that below) but rest assured, no matter how you’re charging it’s the same plug in and go process.

What are rapid, fast and slow chargers?

Chargers are rated in kilowatts (kW), which means the power that they can deliver and therefore the speed that your electric car will charge. Higher-powered chargers will have a higher kW rating and will add charge to your battery faster, these are known as rapid chargers or ultra-rapid chargers.

On the GRIDSERVE Electric Highway we have two types of High Power chargers at Electric Super Hubs, Electric Retail Hubs and Electric Forecourts®, which are capable of up to either 350kW or 360kW. That’s what’s known as ultra-rapid charging and will top you up in minutes.

Then there are our Medium Power chargers, which are capable of 50kW and are often referred to as rapid chargers. You’ll find rapid chargers rated at anywhere up to 90kW. Most modern cars are capable of 50kW with around 90-100kW capability common among most mainstream models. Some electric cars are now starting to be capable of achieving the full 350kW, such as Genesis, Hyundai and Kia models.

There is also slow charging (or what we call Low Power) which is more common at home or at work, where you’re parked for longer – these range from 3kW up to 22kW.

As an example, the Volkswagen ID.3 with 58kWh battery would take eight to 12 hours on a 7kW home charger to get from 0-100%, while on a public rapid charger, you’ll achieve 20-80% in about an hour. On an ultra-rapid charger, that’s closer to half an hour.

What is the difference between AC and DC charging?

AC (alternating current) charging and DC (direct current) charging is all about the type of power that’s being delivered. AC charging is slower and is what you’ll find at home (or on Low Power units) whereas DC charging is what is used at public charging locations for rapid and ultra-rapid charging, such as those on the GRIDSERVE Electric Highway.

When you’re plugged in to an AC unit, the power travels through the cable and into the car. A converter in the vehicle will then convert this into DC to store in the vehicle’s battery. With DC charging, that conversion is already done by the charger, meaning energy can be sent straight into your electric vehicle battery. That’s why it’s faster and more efficient.

What is the difference between CCS and CHAdeMO?

Electric vehicle charging cables have a connector at each end: one plugs into the car, the other into the charger. Which connector you use depends on your EV and the type of charger you use.

While it might look like a foreign language, Combined Charging System (CCS) and CHArge de Move (CHAdeMO) just relate to a type of DC charging connector. Most EVs now use CCS cables, with earlier electric cars such as the Nissan LEAF using CHAdeMO cables. At GRIDSERVE charging points, you’ll often find both CCS and CHAdeMO cables available for use.

You might also come across Type 2 connectors. These are for AC charging and what you’ll use when plugging into your own cable into your home wallbox. Most electric vehicles come with an untethered cable that you can store in the boot for any on-the-go AC charging but pretty much all DC charging units will have cables tethered to the charger – just like a petrol pump.

Preparing your electric car for charging

Electric vehicles are pretty clever so there’s very little you as the driver needs to do to prepare your EV for rapid charging. Aside from checking the electric vehicle charging station you’re visiting has the correct connector, the car will take care of the rest.

If it’s cold, we’d recommend driving a little to your charging destination as batteries charge quicker when they’re warm. Some cars will even pre-condition the battery in advance if you put a charging station as the destination in your sat nav.

It’s also worth considering if you really need to charge yet. Plan your journey so that you can charge when your battery is depleted. Plugging in above 80% will take longer to add charge than if you’re at 40%. You can read more on battery health and charging speeds below.

Where is the electric car charging port?

We’ve all turned up at a petrol station and had the sudden panic of which side the fuel filler cap is on followed by further fear of if there’s an available spot on the right side.

Fortunately for electric car drivers where your EV charging port is located is slightly less vital as the majority of charging points are placed at the end of a parking bay. This means it doesn’t matter if your charging port is located on the left or right, front or back. For those interested, the right rear is the most common place for an EV charge port to be located.

While you’ll have no problems on the GRIDSERVE Electric Highway wherever your plug is located, we’d recommend checking the port’s placement if you’re planning to charge at home.

Are there restrictions on where you can install a wallbox unit? If you can only park a certain way on a driveway to charge it might influence which car you pick – or you’ll have to ensure your own cable is long enough. Or perhaps you live on a main road where reversing out of your drive is not possible. In this case you’ll want a car that can charge at the front.

How to check your car’s charging compatibility

All new electric cars are compatible with almost all electric chargers in the UK. The CCS connector is the current industry standard for public charging, so if you turn up and plug in, your car will happily charge. If you have a CHAdeMO port then you’ll need to make sure the charger has a CHAdeMO connector – this will be clearly marked on charging network maps or apps.

To find out if your car has CCS or CHAdeMO, you can look at your charge port as the sockets look different. If you’re still not sure, then check the owner’s manual, where you’ll also be able to find out the maximum power that your car can accept – this is essentially how fast the battery will top up when plugged in.

Do you need an app or membership to charge your EV?

No, you don’t need an app or membership to charge your EV at the majority of charging stations. GRIDSERVE, along with most other major UK charging operators, allows you to simply plug in and pay via contactless by tapping your card on the payment terminal – just as if you’re buying a coffee from your local barista.

However, there are a number of EV charging apps and membership schemes which promise additional benefits for customers. For example, the GRIDSERVE app offers you the best charging experience by providing live charger availability, map navigation, charge monitoring and access to receipts, as well as access to charging discounts.

How does an electric car charger work?

Charging an electric car is simple: plug in, pay and away you go. But that basic process is hiding some clever technology and electrical engineering. Inside the charging unit at the end of your parking bay is some advanced software and hardware.

The charger, along with the power cabinets you’ll see located nearby, takes AC power from the grid and converts it to DC power ready to be flowed into your car’s battery.

Once you’ve plugged the charging cable into your car’s socket, the charger will communicate with the car’s battery management system to initiate a charge. Once everything is confirmed, the ‘handshake’ is complete, power can flow and the charging session begins.

This happens through heavy duty, liquid-cooled cables which are designed to increase charger efficiency and reduce heat loss during the transfer. The charger is then part of a connected network allowing the charging operator monitor performance remotely.

Is it safe to charge an electric car in the rain?

Yes, it is completely safe to charge an electric car in the rain (or any other bad weather like snow or sleet). That’s because the cable is not live until it’s plugged into a car and the charger and vehicle have confirmed a safe connection.

The charging equipment, whether that’s the cables, connectors or vehicle ports, are all designed as a sealed, water-resistant unit and tested to work in all weathers against a number of international safety standards.

Common charging issues and how to fix them

Electric cars and chargers are complex bits of technology and so occasionally things don’t run completely smoothly. It’s not always an indication that a charger is faulty, either. Common charging session issues can include faulty physical connections, outdated software, open windows or locked vehicles.

Why won’t my EV connect to the charger?

One of the most common reasons that are charger won’t connect to a charger is because it’s not fully inserted into the socket. Charging cables can be heavy and often need a firm push to fully click into place in your car. If this isn’t done, your EV won’t communicate properly with the charger.

Sometimes cars can also have individual quirks as to the state they need to be in so that they can accept a charge. Here’s a few things you can try if you run into problems:

1. Remove the connector and place it in the holster.
2. Turn the vehicle on, then off.
3. Ensure all vehicle doors and windows are locked.
4. Reinsert the connector into the charging port.
5. Support the cable’s weight and attempt to restart the charging process.

And although it’s pretty rare, software compatibility issues between new cars and chargers sometimes occur. At GRIDSERVE, we have dedicated tech teams working with our charging partners and car makers to get these fixed with updates as soon as possible.

Electric car charging cost

One of the many advantages of driving an electric vehicle is that running costs are low because you’re not paying for petrol or diesel. But how much does it cost to charge an electric car?

There are numerous variables involved in calculating the cost of running an EV:

• Vehicle weight: The heavier the vehicle the less efficient it will be and you’ll need to plug in more often
• Driving style: If you accelerate quickly or are harsh on the brakes, your energy use per mile (just like your miles per gallon) will be higher and you’ll need to charge more regularly
• Battery size: A larger battery will cost more to charge on a single visit – but that’s offset by the fact it’ll last longer before needing to be recharged
• Where you charge: Charging from home is the cheapest way to charge your EV with regular top-ups for longer journeys on the public network

Overall, though, if you have off-street parking and charge predominantly at home and work and then use the public network for top-ups, running an EV will be much cheaper than a petrol or diesel, regardless of the cost of electricity at public chargers.

How to find out how much you’re paying

The cost of charging on the GRIDSERVE Electric Highway and at other public charging points varies depending on when and where you’re plugged in.

The cost per kWh of the charger you’re plugging into will be displayed on the charger screen or payment terminal. You can also check pricing ahead of your visit, either online or via the app.

Electric car charging cost vs petrol and diesel

The cost of charging an EV compared to petrol and diesel cars depends on the type of charging you do and the price fluctuations of fuel.

If you do most of your charging plugged in at home it’ll be much cheaper power an EV than to refuel with petrol or diesel – around 3p per mile compared to roughly 20p per mile from a petrol pump.

It’s still cheaper even if you can’t always charge at home and have to plug into the public network charging, with the average cost sitting at around 18p per mile. 

How does time of day impact charging prices?

The cost of electricity fluctuates during the day and so many forward-thinking energy companies now offer electric car home energy tariffs, which when coupled with a smart wallbox charger, will secure you great cost savings for charging at off peak times (i.e. overnight when electricity is much cheaper per kWh).

Charging on the public network is similar with some providers offering variable pricing during off-peak times. For the latest on how much you’ll pay on the GRIDSERVE Electric Highway, visit our pricing page or download our app.

Does charger speed affect cost?

The cost of charging on the GRIDSERVE Electric Highway and at other public charging points varies with the cost per kWh often tied to the charging power of the unit you’re plugged into.

That typically means a slower, AC-powered unit often found in car parks or shopping centres will be cheaper than a faster, higher-powered charger that you’ll see at motorway service areas.

Electric car charging time

The answer to the question of how long it takes to charge an electric car is it depends.

There’s no one-size fits all answer because charging speed depends on both the make and model of electric car and the charger that you plug into. Not to mention a range of other factors, such as temperature and current battery State of Charge (SoC).

Let’s dig into that a little more.

How long does it take to charge an electric car?

Rather than focusing on how long a full charge takes, it’s often better to think about how many miles you can get from a top-up charge. This ensures you have enough to keep your car running until you get to the next charger.

Although the figures vary from model to model, the average number of miles of range you can add from an hour of charging are as follows:

• 7kW: up to 30 miles
• 22kW: up to 90 miles
• 50kW: up to 90 miles on a 30-minute charge
• 150kW: up to 200 miles on a 30-minute charge
• 350kW: over 200 miles in just 20 minutes

What’s the difference between kilowatt hours (kWh) and kilowatts (kW)

Instead of a car being defined by its engine capacity, expressed in litres, it’s now defined by its battery size and the unit of this is kilowatt hours (kWh).

EVs have a battery that can have a capacity anywhere between 30kWh and around 100kWh, with the numbers indicating the total of the battery’s energy storage over a specific time.

On average, electric cars consume 34.6kWh to travel 100 miles, so a 30kWh battery will have a range of less than 100 miles. A battery twice as big will have twice the range. Naturally, a larger battery will take longer to charge as there’s more energy required.

However, that’s not always the case as some cars have a higher charging capability – this is listed in kilowatts – and is the speed at which energy can be delivered into the battery.

What is an electric car charging curve?

Charging times are often quoted from 20 to 80% and that’s because of the charging curve, where charging is faster when the battery is not completely empty or nearly full.

The headline figures which you’ll get from electric vehicle chargers are peaks and not constants, that means the power you’ll actually see differs depending on your battery’s State of Charge (SoC).

Each model is unique with a different charging curve that achieves higher power at different points. The graphic below shows the basics of a charging curve.

Electric car charging to 80%

As a general rule, if you’re above 80%, the car will slow the maximum charging power to avoid the cell voltages exceeding their limit.

That means the time it takes to get from 80% to 100% on a public ultra-rapid charger is disproportionately long to the rest of the charge.

It’s why it’s recommended to charge to 80% and set off, stopping off later in the journey for another top up if you need. It’ll be quicker in the long run and stop you taking up a charging bay from another EV driver. 

How much energy does an electric car battery need to reach 100%?

The bigger the electric car battery, the more energy you need to fill it. However, the amount of energy your battery needs to achieve 100% is more than the kilowatt-hour (kWh) capacity of the battery.

Why? Well, the lithium-ion battery is not like an empty petrol tank and on average needs roughly 10-15% more energy than its size.

The biggest reason is energy lost as heat during the process, while a small amount of energy will also be used by your vehicle during the charging process to operate key systems – a bit like streaming music on your phone while you charge.

Why is my electric car not charging at full speed?

There are a number of factors that will affect your charging speed, with the biggest being the temperature.

Just like extreme cold and heat can impact the range of your electric car, it can also affect your car’s charging capability.

Batteries operate best at a comfortable temperature (a bit like us), and you’ll only achieve maximum charging power with the battery warm. On a cold day everything slows down.

Other reasons include the State of Charge of your battery (over 80% and things slow down a little) and the grid connection where you’re plugged in (some charging stations have to split available power between customers).

What are the fastest charging electric cars?

Many cars now claim 150kW+ charging capability while some of the latest top-end models are now capable of achieving over 300kW.

It’s not all about outright peak power, though, as in order to deliver energy (and therefore miles) the quickest, it’s all about how long a car can maintain its advertised top rate (this is known as the charging curve).

Using figures from ev-database.org we’ve compiled a list of the fastest charging electric cars based on ‘miles per hour’. Rather than a 0-60mph time, it takes the average power of a car across a 10 to 80% charge and calculates how many miles it would add over the course of an hour.

The Porsche Taycan – freshly updated with higher power charging – takes top spot ahead of the Audi e-tron GT, which shared most of its under-the-body engineering with the Taycan. Check out the league table below.

A complete guide to EV charging etiquette

It’s important those using the public charging network do so in a way that makes it safe, accessible and stress-free for everyone.

And as the number of EVs on the road continue to rise, charging considerately will become even more vital. Here are a few tips on EV charging etiquette – or as we like to call it the GRIDSERVE Electric Highway Code of Conduct:

1. Don’t block bays if you’re not charging
2. Don’t overstay after charging
3. Choose the right charger for the time you’ll be staying
4. Communicate with other EV drivers to avoid queue jumping
5. Look after the connectors
6. Don’t unplug someone else’s charger
7. Make the charging area clean and comfortable for everyone
8. Don’t press the emergency stop button
9. Share your advice and experiences with others