Guide to charging an electric car

Slow chargers, fast chargers, and rapid chargers; a guide to charging an electric car

Chris Knapman Murray Scullion
Aug 31, 2019

If you’re in the market for an electric car, one of the major considerations is how you will charge it. If you have off-street parking at home the obvious solution is to plug the car in overnight, taking advantage of cheaper Economy 7 electricity tariffs in the process, provided you don't venture too far away from home during the day.

However, you can also find charging points at many workplaces, car parks, motorways services and so on, adding to the convenience of electric vehicle (EV) ownership, as well as making longer journeys possible. 

How long does it take to charge an electric car?

Range anxiety (the fear of running out of battery charge) must be the biggest worry about electric cars for potential owners, but a close second is how long it takes to charge. And the answer is that it really depends on what kind of charger you’re using. But be prepared - all electric cars take substantially longer to charge than it does to fill up with petrol or diesel.

  • Slow chargers (3kW) - typically charge at up to 3.6kW hours, although they are generally referred to as 3kW units. They are most commonly installed as home chargers and can deliver a full charge in about 8-12 hours, although it can be longer for EVs with the highest capacity batteries.
  • Fast chargers (7-22kW) - operate at twice the speed of slow chargers. Full charges take 4-8 hours. Typically these cost upwards of £1,000. Though they can be bought for home use, they are typically found in public places.
  • Rapid chargers (43-50kw and 120kW) - these chargers can top up an electric car to around 80% battery from empty within 30 minutes. You'll find them at large motorway service stations, but not all electric cars accept rapid charging. Due to the amount of power required, these chargers can't be installed at home.

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How to charge your electric car at home

Charging your electric car at home is the cheapest and easiest option. The good news is that it’s very easy to do, as it’s pretty much the same as plugging in an appliance like a kettle or toaster.

Generally, if you’re charging from home (whether that be on your drive or on the street) you’ll need to use your own cable. Simply plug one end into the car, and the other into the power source, and you’re done. Most electric cars have a separate storage area in the boot to keep the cable too.

You can charge most electric cars using a three-pin plug, but it’s very slow, and will typically take around eight hours. This is fine for charging your car overnight, but it will grow tiresome having to wait that long all the time. Be aware that if you can't park within a cable's length of a plug, many electric cars will prevent you from charging the car through an extension lead, so you may need to find another way to charge.

If you do have off-street parking, it’s worthwhile investing in a dedicated homecharging unit. These typically sit in your driveway, are waterproof, and are wired to your fuse box. They also turn off when your car is fully-charged.

Many manufacturers will supply a wall-mounted slow charger when you buy a new electric car, or if not, there are Government subsidies in place that provide you with £500 off the cost of purchase and installation. Without subsidies, 3kW chargers typically cost between £350-450.

You can also buy fast chargers for your home. They are generally twice as fast as slow chargers, and will take between 4-8 hours to fully charge a car. There’s a price to pay though - as these typically cost around £1,000.

How to charge at electric car charging points

Electric car charging points are spread out around the country. You can find them at motorway service stations, supermarkets, public car parks, work places, and some residential streets in places like London and Birmingham.

These require a little bit more thought in terms of connecting to them. Not only do you need to plug into to them, but you need to pay for it too.

Pod Points' charging points require you to supply your own cable, which is no problem if you know what you need. But you also need to be signed up to Pod Point. Essentially, you pay for your usage via an app, and also lock, and unlock your charging point via the same app. It’s intuitive and easy to use, especially for people who regularly use apps.

Ecotricity, which provides chargers at a lot of motorway service stations, uses a similar platform. You communicate with the charging system via an app, and once you’ve paid, you have access. Ecotricity does provide its own cables though.

ChargeMaster is the UK’s largest electric charging network, and runs the POLAR brand which you might see dotted around at charging points. It’s recently been bought by oil brand BP, and will soon help in electrifying BP’s petrol station forecourts. POLAR charges a monthly rate, and then users charge their cars from POLAR branded charging points for free, or very cheaply (around 9p per KWh).

However, charging points might be coming closer to your home soon enough if you live in certain places. The London boroughs of Richmond, Hounslow, and Westminster have all set up charging points that are adapted from lamp posts. The systems used on these are retrofitted to lamposts and are currently being trialled in attempt to improve air quality in the capital.

Example electric car charging times

Renault Zoe Z.E. 40Nissan Leaf 40kWBMW i3 94Ah
Driving range (real-world approx)150 miles150 miles120 miles
Slow charger13.5 hours16 hours11 hours
Fast charger (7kW)6 hours8 hours4.5 hours
Fast charger (22kW)2 hours8 hours3 hours
Rapid charger to 80 per cent capacity1 hour40-60 minutes35 minutes 

How much does it cost to charge an electric car?

Fuel costs for electric cars are much less than petrol powered vehicles, simply because electricity is cheaper than petrol. However, it’s not that simple.

A typical 7kW homecharger from Chargemaster costs £322, and it’ll fill a Nissan Leaf in around six hours for roughly £5.60 overnight - with enough charge to travel around 140 miles. Charging at home, at night, is easily the cheapest way to top up your car.

However, there will be a time when you need to charge on the go, and this gets more expensive. The fastest charging points at motorway service stations may well get you to 80% in around 30 minutes, but they charge a premium. Service stations at peak times might cost you double the price it would cost to charge at home. But Ecotricity for instance, will halve this cost if you use them as an energy provider at home.

When comparing an electric BMW i3 with a petrol BMW 318i, the average cost of fuel for the i3 runs at 3.7p per mile, whereas the petrol-powered 318i comes to around 14.2p per mile. Electric cars are also free to tax, while petrol powered ones aren’t. However, insurance on electric cars is generally higher than petrol-powered ones.

In short, the total cost of running an electric car and a petrol powered one are quite similar when depreciation, insurance, and servicing are taken into account. In total, the BMW i3 comes to 67p per mile, whereas a petrol-powered BMW 318i costs 74p per mile. Bear in mind, too, that the 3 Series is also a larger car.

Read the full report on how much an electric car costs here

Sign up for public charging

Public charging points are run by a variety of companies, most of which charge for the use of their electricity in the form of a monthly subscription or on a pay-per-use basis. Either way you will need to sign up with the relevant provider to gain access to their charging points, which you then unlock either by swiping a membership card or using a dedicated app.

Currently, there is no single way of paying for public charging, so unless you plan to visit the same public charging points exclusively, it is worth signing up with two or three providers to ensure you’re covered as and when you need to top up.

If you live in London, for example, and have no off-street parking, you’ll need a subscription with Source London, which has 7kW chargers (both Type 1 and Type 2), as that’s the cheapest way to charge (without a subscription, the cost of a minute’s electricity is almost double).

Chargemaster’s Polar network has the most chargers around the country – in the region of 6,000 – which can be accessed using a smartphone app, or you can pay £7.85 a month to join the Polar Plus scheme, with around 80% of its chargers then free to use.

One network that doesn’t require membership or an app is Instavolt, which accepts payment using a contactless card. This is probably the future, but until all the providers agree to accept payments this way, Instavolt is almost alone.


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