How much does it cost to charge an electric car at home?

·6-min read
Charging an electric car at home will be around a third cheaper under the Government’s energy price guarantee, compared with the planned price cap, according to new analysis (John Walton/PA)
Charging an electric car at home will be around a third cheaper under the Government’s energy price guarantee, compared with the planned price cap, according to new analysis (John Walton/PA)

With domestic electricity prices now capped for the next couple of years, electric-car owners will be wondering how much it’s going to cost to charge their vehicle at home. Prospective electric-vehicle (EV) buyers might also be weighing it up against the cost of running a petrol or diesel car.

Let’s be clear that there are an enormous number of variables involved in car-charging costs, including the make of car, the battery size, and your electricity tariff. Treat the figures below as a guide rather than an absolute. That noted, here’s how to work out the cost of recharging at home, the extra costs you have to consider, and some tips on keeping these costs down.

All the figures shown here are based on the Energy Price Guarantee (EPG), which comes into force from October 1.

What is the price of a full recharge for an electric car?

There’s a basic formula you can use to work out the cost of fully recharging an electric car, which is:

Your electricity tariff (in kWh) x car battery size (in kWh) / 100.

The maximum cost of electricity under the new government price cap is 34p per kWh. So, to fully recharge a Fiat 500e with a 37.3kWh battery, you’d be looking at a cost of £12.68 (i.e. 34 x 37.3 / 100).

For a bigger electronic car, such as the Mercedes EQV with a 90kWh battery, the cost is around £30.60.

Now, we said this formula was basic, and there are a few other factors to consider here:

  • Your electricity tariff might be cheaper than the government cap.

  • The transfer of electricity from socket to car battery isn’t 10 pre cent efficient. According to Which’s figures, for example, it actually takes 42.9kWh of power to recharge that 37.3kWh battery in the Fiat 500e, so that might tip the cost of a recharge up by around 10 per cent.

  • The car’s battery is unlikely to be fully depleted when you charge (unless you were towed home), so that will reduce the cost of most typical recharges.

  • The range of the car when fully recharged should also be considered. That’s why, when comparing the cost of two cars, it’s more sensible to think in terms of cost per mile, rather than the cost of a full recharge. Smaller cars, such as the Renault Zoe, work out at 10p per mile to run whereas a large SUV can cost up to 14p per mile, says Which.

What is the cost of a home-charging point for an electric car?

If you’re regularly topping up the car battery at home, you’re going to need a charging point. It’s not wise to regularly rely on standard plug sockets, because electric cars are hugely power hungry. If you stick to conventional mains sockets, you’ll suffer from slower charging, you might overburden the home’s electricity supply, and you run a higher risk of electrical fires.

The fitting of a regular 7kW charger with a tethered cable costs £949 from EDF Energy, including installation. At that output, you could fully charge a Tesla Model S in around 11 hours.

More expensive ‘fast’ home-charging points are available. A 22kW model would cost £1,599 and cut the Tesla Model S charging time down to only four hours. However, not all electric cars can handle the output from these fast chargers, so be sure to check your car’s specs before ordering a charging point, or you could end up throwing money away.

How do you find free electric car charging at public points?

One way to keep those charging costs down is to take advantage of free charging at public venues, such as supermarkets, shopping malls, and cinemas. With luck, you might even find one at a campsite.

Frequently, these public-charging points are topped up by solar panels, allowing venues to keep providing charging for free even during the energy crisis. However, you almost always need to sign in with an app for the charging-point network and you’ll often need to bring your own charger cable, too.

Not all public charge points are free. Indeed, you’ll often pay a stiff premium for fast chargers at places such as motorway service stations, in the same way they typically stick 10p onto the price of a litre of petrol.

Zap-Map has a map that shows 30,000 UK public-charging points and their current status. Tesla also has its own ‘Supercharger’ network, where a 15-minute stop can keep you going for another 170-odd miles, depending on which model of Tesla you own.

Cost-cutting tips for charging an electric car at home

Here are a few other tips for saving money on electric car charging at home:

  • Although rarer now, some energy companies offer tariffs designed for electric-car drivers, where you might get cheaper rates for charging overnight, when demand on the grid is lower.

  • Electric cars really start to make sense when combined with solar panels – and batteries to store this energy. You can use any excess energy not needed in the home to charge the vehicle.

  • Many workplaces now offer free charging points for employees. Sceptics might feel this perk is designed to make sure that you are in the office nice and early to reserve a spot.

What is the cost of replacing the batteries on an electric car?

There’s one thing electric-car manufacturers aren’t so keen to talk about and that’s the cost of replacin batteries. All rechargeable batteries eventually deplete with age, to the point where they can no longer hold a charge.

Most new electric cars come with a battery warranty. A typical warranty will guarantee a minimum 70 per cent health after eight years/100,000 miles (whichever comes sooner). If the battery performance dips below that level, you may be entitled to a replacement battery, but make sure to check the precise details of the battery warranties before you purchase the car.

The costs of replacing batteries on an electric car are eye watering, especially from main dealerships. For instance, the 24kWh batteries in a Nissan Leaf can cost upwards of £12,500 and Tesla batteries have been priced at £15,000. However, there’s an emerging market of third-party replacements that can cost a half or even a third of the official prices. Beware, though, that fitting these third-party replacements will almost certainly break the original manufacturers’ warranties.