EV charging speeds

How long it takes to charge an electric car isn’t a straightforward calculation, which isn’t exactly helpful if you’re new to the world of EVs.

It’s true that there is no single answer to the question, but that doesn’t mean that we can’t make an educated guess, based on an understanding of the different types of charger, the size your EV’s battery and how quickly it can take energy onboard. The time it takes to charge is falling, as the latest technology is rolled out roadside, with as little as 15 minutes now possible. We could even find ourselves, in a few short years, charging an EV in the same time it takes to fill a tank of petrol or diesel.

What’s the difference between kW and kWh?

As you become part of the electric revolution, you’ll need to get used to the new jargon, so there are a few basic terms to understand.

The first is the kilowatt (kW), which is the power of a charger. Depending on how and where you usually charge, the power can range from 3.7kW to 350kW. The greater the power, the faster it can charge a car (in most cases).

Then there’s the kilowatt hour (kWh), which is the how much power a car’s battery can hold. The bigger the battery, the longer the potential range – and the longer it takes to charge.

Just by adding these two variables together, there are already a huge number of possible answers to the question of how long an EV takes to charge. But a decent rule of thumb is to take the battery capacity (in kWh) and divide it by the power of the charger (in kW): so if you have an EV with a 64kWh battery and use a 7kW charger, it will take just over nine hours to fully charge from empty.

Charging speeds at home

If you have off-street parking, you can charge your EV from your domestic AC electricity supply. You can use a regular three-pin plug, but you could be looking at 30-35 hours for a full charge.

A better option is to have a wallbox fitted, most of which charge at 7kW (and also use AC power). This means that the majority of EVs will charge in 6-8 hours, so they can be charged overnight, while sitting in a garage or a on drive.

It is possible to get faster home chargers, but many EVs can’t take higher AC charges and you’ll need to get your energy supplier to upgrade you to three-phase power. Frankly, it’s not worth the hassle for most EV drivers.

For more info on charging at home - read our EV charging at home guide.

Workplace charging speeds

If you’re lucky enough to charge at your workplace – lucky, because it could cost you next to nothing to run your EV – you’re likely to be using the same speed as at home, with 7kW chargepoints tending to be the best choice for many employers.

Some organisations with fleet operations – especially if they have electric delivery vehicles – could soon start upgrading to 50kW chargers, for faster turnarounds. If you can access one, a full charge should take 60-90 minutes.

For more info on charging at work - read our EV charging at work guide.

Charging speeds at public charge points

If you don’t have off-street parking, you’ll find that on-street chargers installed by local authorities charge at slower AC rates, with 7kW chargers common, along with 5.5kW lamppost chargers, so overnight charging is a good option, if there’s one on your street.

There are also 11kW and 22kW on-street AC chargers, which are faster, but you should check if your car can receive a charge at that rate before using them: it won’t be a faster charge, but you’ll have to pay the higher rate for your electricity, making it more expensive.

On motorway service stations, hotels and in some on-street locations, you will find 50kW DC rapid chargers, such as the GRIDSERVE Electric Highway units. An 80% charge can take around 45 minutes, giving you a break from driving and plenty of time to stretch your legs, and have a coffee or something to eat.

The latest generations of ultra-rapid charger can currently have outputs of between 100kW and 350kW, so EVs that can receive power at these rates can charge to 80% in just over 20 minutes.

Who knows how fast chargers will be by the time the 2030 ban on the sale of petrol and diesel cars comes into force?

For more info on public charging - read our EV charging on the road guide.