Charge an Electric Car: How Long Does it Take?
Electric cars are getting more and more popular among car buyers in the UK. Whether you already own an EV or are planning to buy one, you might still be unsure as to how long does it take to charge an electric car. Don’t worry, we got your back.
After reading this article, you’ll know the factors that affect EV charging speed and the different types of EV chargers available in the UK. This information will help you estimate the charging time with a good degree of accuracy, allowing you to plan your routes accordingly. You will never have to suffer from range anxiety again!
What Influences EV Charging Speed?
The answer to the main question in this article is not immediately straightforward. Several factors affect how fast or slow an EV will charge, from environmental considerations to the charging infrastructure. So, before you can estimate your car’s charging speed and plan your route, you must first understand these factors. Here they are:
The capacity of the battery
The more capacity your car’s battery has, the more range it will provide, but also the longer it will take to charge. Battery capacity is usually measured in kilowatts-hour (kWh), which is a unit of energy you may already have seen in your electricity bill. EV battery capacity currently ranges from 20 kWh to over 100 kWh.
The battery’s state of charge
Most current battery packs on cars use lithium technology. Lithium batteries don’t like being completely empty or full, so many manufacturers recommend charging between 20 % and 80 %. This means you may not always fully charge your battery. Also, EV charging speed is typically reduced when the battery level is too low or too high, in order to protect the battery.
The type of charger it’s plugged into
Chargers for electric vehicles come in many shapes and forms. They supply different power outputs, resulting in vastly different charging rates. We’ll look into them in more detail in the next section.
The charging power that is being supplied
The higher this is, the quicker the battery will charge. The charging power depends primarily on the type of charger being used and is controlled by your car’s Battery Management System (BMS).
The temperature
Charging efficiency takes a dive when the weather is very cold, so you will see longer charging times. The BMS will also limit the charging power if the batteries are overheating.
EV Charger Types in the UK
The type of charger you use has the biggest influence on how long charging will take. EV chargers range from simple home units you can plug into the wall outlet, to dedicated devices that pack some serious punch. They can usually be grouped into a few main categories, which we’ll explore in more detail below.
Slow Charging (2 kW – 7 kW)
The most basic chargers you will find come with the standard 3-pin UK plug and will go on any domestic 230-volt wall outlet. This makes them practical and easy to use, as you can charge your car without any special adaptations to your home. However, they are also the slowest to charge, as they are limited in how much current they can draw from your electrical supply.
The result is a very long charging time. Most small electric cars will take between half a day to two full days to reach a full state of charge with this option. Therefore, this kind of charger is generally only useful for occasional drivers who don’t cover many miles every single day and who own EVs with smaller battery packs.
Fast Charging (7 kW – 22 kW)
This category includes some home EV chargers as well as public chargers. Unlike their slower counterparts, home chargers in the 7 kW range require higher electrical capacity, which means you have to install a dedicated wall box.
However, if you can afford this investment, you should see your charging times essentially halved. This makes a home fast charger a convenient solution that is more than enough for most people’s needs. Several EVs can be fully charged overnight this way, so your car is ready to go in the morning.
On the other hand, 22 kW chargers require a three-phase electrical supply, which makes them more difficult and expensive to implement at home. You will generally find them in public charging stations, mall parking lots, and maybe even at your workplace. On average, you should be able to replenish your entire battery in 2 to 3 hours using this method.
Rapid Charging (50 kW – 150 kW)
You will find these chargers at motorway service stations and other public charging locations. Most rapid chargers supply 50 kW, but that can go up to 150 kW. They are the best solution when you are in a hurry, for example when making a quick stop during a long journey. You may be able to add about 75 miles of range in half an hour, so you can quickly continue on your way.
Keep in mind that rapid charging may accelerate wear and reduce the lifespan of the battery a little bit. Ideally, only choose to rapid-charge when you absolutely need it (for example, during longer trips). For everyday commuting and occasional top-ups, consider using a normal fast charger instead.
Ultra Rapid Charging (150 kW – 350 kW)
As the infrastructure for electric vehicles becomes more robust, charging speeds are getting higher and higher. Tesla’s famous Superchargers can deliver up to 250 kW, allowing your Model S to gain 200 miles of range in about 15 minutes. Although still rare, some ultra-rapid charging stations can already deliver up to 350 kW. Very few vehicles currently in the market are even capable of supporting this, but with battery technology constantly evolving, this could very well change in the near future.
How to Estimate EV Charging Time?
You can make a quick estimate of how long it takes to charge your car from empty to full using some basic maths. All you need to know is the battery capacity of your car and the charging power of your charger and/or vehicle. The calculation goes as follows:
Time to full charge (in hours) = battery capacity (in kWh) / charging power (in kW)
Let’s see a practical example. Imagine you want to charge a Tesla Model 3 with a 50 kWh battery pack, using a 7 kW home charger. It should take approximately 50 / 7 = 7.15 hours to completely charge the battery.
Remember that the rate of charging usually slows down a bit when the battery is almost full. So, while this calculation can give you a pretty good idea, it won’t be 100 % accurate. In the above example, you can expect something closer to 8 hours for a full charge. The more powerful the charger you are using, the sharper the drop in charging rate near full charge. Therefore, the results are less accurate with rapid charging.
It is also somewhat scalable. So, for example, if your battery was 50 % full, it would take about half as much (around 4 hours) to reach a full charge. If it was 25 % full, it would take about 6 hours, etc.
Another important consideration is that most electric cars will have a maximum charging rate to protect the battery. For example, many EVs are limited to about 50 kW. You can still safely plug into a 150 kW rapid charger, but it will only draw charge at a rate of 50 kW. Check your owner’s manual to know how much charging power your vehicle will take, and make sure to consider this in your calculations.
Conclusion
Electric vehicles have several advantages when compared with their internal combustion engine counterparts, but their main drawback is still energy storage. You can’t just pull up to a petrol station anywhere and fill up the tank in seconds! Fortunately, the EV charging network in the UK is now highly developed, and this will only get better.
While driving an EV does require a little bit more planning, knowing the different kinds of chargers you may have access to and how to estimate charging times will make your life much easier. We hope that, having read this article, you will feel more confident about embracing the future of electric mobility.
