Finance Options Available on Purchases Over £1000 - No Upfront Cost - Call for More Information
We have engineers across the UK, so we can install home, commercial or workplace EV chargers nationwide.

What does kW and kWh mean for electric cars?

What does kW and kWh mean for electric cars?

Kilowatt and kilowatt-hour are units of measuring energy, but they represent different concepts and measure different aspects of electricity when it comes to electric vehicles.

But what is kilowatt (kW)? What is kilowatt hour (kWh)? What is the difference between kilowatt and kilowatt-hour (kWh) for electric cars? 

Keep reading to learn everything you need to know about kilowatts (kW), kilowatt hours (kWh) and electric cars.

What is a kilowatt (kW) for electric cars?

kW stands for kilowatt and is a unit of power used to measure the rate at which energy is consumed or produced.

In the context of EV charging, kW represents the rate of power moving from your electric car charger to your EV battery, indicating how fast the charging station will charge your car.

For instance, if an electric vehicle charger has a power rating of 7kW, it means that it can deliver 7 kilowatts of power to the vehicle per period of time, usually per hour, with 1 kilowatt equalling 1000 watts.

Rates of power for EV chargers in the UK include 3.6kW, 11kW, 7kW, 22kW, 50kW and so on – up to 350kW for ultra-rapid charging points – although this is rare.

The general rule of thumb is the higher the kW rating of the charger, the faster your electric car battery will charge. Of course, there is a caveat to this. While DC EV chargers (rapid and ultra-rapid public charging points) always work on the basis of the higher the power ratings, the faster the charge, this is not always the case for AC charging.

Your electric car will have a maximum onboard charging rate that converts alternating current from the electricity grid into direct current (the energy used to charge your electric car battery), so make sure to keep that in mind if your EV won’t charge any faster than your maximum charging rate, even if you charge with a higher charger.

For example, the Kia Niro EV has a maximum AC charging rate of 11kW, meaning even if you top-up with a 22kW charger, the Kia will only charge at 11kW. Additionally, the Nissan Leaf has a maximum onboard charging rate of 6.6kW, meaning even with a 7kW, 11kW, or 22kW charger, it will only charge at 6.6kW.

kW is also used to express the power output of the electric motor within the electric vehicle. A higher kW rating for the electric motor generally results in a more powerful and responsive driving experience.

What is a kilowatt-hour (kWh) for electric cars?

A kilowatt-hour, or kWh, plays a crucial role in understanding the capacity of electric car batteries. In the context of EVs, kWh measures the capacity of the electric vehicle’s battery, such as how much energy can be stored and, in turn, how much range your electric car has (the maximum distance your EV can travel on one charge). Think of kWh like the size of a fuel tank.

A larger battery capacity, expressed in kWh, means the electric vehicle can hold more energy. Consequently, a higher kWh means a longer driving range before the need for recharging. 1 kWh of energy means an appliance used 1kW of energy for an hour.

Take the Nissan Leaf, for example. With a 39kWh battery capacity, it means the battery can store and provide 39 kilowatt-hours of electrical energy.

Compare the Nissan Leaf to the Audi Q8 e-tron, with a battery capacity of 89 kWh, and you will be able to travel further with the Audi on one charge than the Nissan Leaf because of the longer range and larger battery capacity.

While kWh gives an indicate of an EV range, the range of an electric car can vary depending on a number of factors, such as weather. Learn more about what impacts EV range in our blog, or read our tips on how to mitigate a drop in range.

Will my electricity bill be in kW or kWh?

On your electricity bill, you are billed for the amount of energy consumption, measured in kilowatt-hours. The energy bill might show the rate at which you used energy in kilowatts (kW) at specific times, but the total consumption is expressed in kilowatt-hours (kWh) of electricity.

Summary – What’s the difference between kW and kWh for electric cars?

In short, a kW means kilowatts and is a unit of power measuring the rate at which energy is consumed or produced. For electric cars, kW represents the rate of power from the charger to the EV battery, indicating how quickly the charging station can charge your car. Whereas kWh, meaning kilowatt-hour, indicates how much energy your EV battery can store, therefore indicating the electric car’s total range.

Interested in charging for cheaper, greener and faster?

The benefits of home electric car chargers are endless – cheaper energy usage with off-peak overnight charge scheduling, more convenient EV charging sessions from your house, and faster charging sessions than using a domestic socket.

Take advantage of these benefits by investing in home EV charger today. At We Power Your Car, we offer a range of home EV chargers to suit your electric vehicle needs, from EV charging points providing 7 kW of power to 22kW EV chargers.

Contact us at 03333 44 96 99, browse our range of market-leading electric car chargers, or contact us via the form below. With our team of accredited and experienced installers across the UK, we can install wherever you are – with first-class customer service.


Related posts:


Contact Us Now

Enter your information below, and one of our expert advisors will be in touch shortly.

Tethered charger

This type of electric charger has it's own cable to charge your car.

Socketed charger

This type of electric charger requires a seperate cable to charge your car.

Spread over a 60 month period.

Tenants and homeowners are eligible for finance.

You decide the amount of months.

Minimum of £1000.

We will contact you to process the credit application. Approval is subject to application, financial circumstances and borrowing history. 13.9% APR representative. T&Cs apply.

Your order is not confirmed until your application has been approved.

Underground cable

We lay SWA cable laid at 600mm deep, with a protective cable warning tape laid 150mm above the cable. These are laid on a sand or sifted sand soil bed then backfilled.

Overhead cable

We position overhead cables at a minimum height of 3.5m and are run along a catenary wire. The cable run should not be accessible to vehicles.

Standard Installation
Our instant price is fixed if it falls within our standard installation package plus any additions that you have selected (extra cabling for example). This package covers the majority of homes in the UK. Before we undertake your installation we will carry out a digital survey to check that nothing has been missed. After reviewing the survey results some additional work may be required in order to complete your installation safely and to the required standards. If this is the case, we will contact you well before the installation date and advise the cost of any required work. You can then continue with your installation, or alternatively we will refund you in full if you do not want to proceed.

Included in our standard installation is :
• Fitting of a single phase charge point to a brick or plaster wall or other suitable permanent structure
• Up to 10 metres of cable, run and neatly clipped to the wall between the electricity supply meter / distribution board and the charge point.
• Routing of the cable through a drilled hole in a wall up to 500mm (20 inches) thick if this is needed.
• The fitting and testing of electrical connections and protections required for the charge point.
• An additional three way consumer unit, if required
• Installation of a Type A RCBO in an RCBO enclosure
• Up to 3 metres of plastic trunking to conceal interior wiring.
• An O-pen earth protection device if the charge point requires it. (This is NOT an earth rod)
• Up to 4 hours of labour from your installer to complete the work.
• Electrical testing of the whole installation.
• Handover and setup of the charge point and any app that may be needed.

Not included in our standard installation (additional work) :
• Where the installation requires additional cabling over and above the amount you have told us about.
• Upgrade/replacement of the main incoming supply fuse where the local DNO (eg Northern Powergrid) would need to attend site.
• If the charge point is to be mounted on a post/pedestal rather than an existing wall and where you have not selected a post as an extra cost option in your order.
• Installation of a charge point to a three phase supply.
• Where gas and water mains bonding (earthing) is not in place at your property. If this is not in place, additional work would be required before installation of the charge point.
• Any groundwork that has not been selected during the order process.

A Surge Protection Device is not included in our standard installation. 

What else you need to know :
• On the day of installation, please ensure that the area around your consumer unit (fuse box), incoming electricity supply meter and proposed charge point location (including where the cable is expected to be run) is clear and free of obstructions.
• We will need your WiFi password as part of the installation process in order to connect your charge point to the internet. Please have this available for the installer. Details will not be kept.
• The charge point must be on your own designated off road parking.
• The charger will be fixed in line with current guidelines at a height where it cannot be hit by a vehicle.
• Our installers are not able to enter loft spaces; lift floorboards or flooring; take apart any furniture of work above a height of 2m. If you anticipate that any of this may be required, then please contact us and we can discuss in more detail and provide you with a quotation.
• Should there be extreme weather conditions our installers may not be able to continue with you installation if it is not safe to do so (for example flooding). They will always do their best to complete the work where they can.

If you have any questions then please contact our customer service team who will be happy to help. Please also read our terms and conditions.