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EV charging levels explained

August 31, 2021 | Wesley van Barlingen and Joseph D. Simpson

Driving electric vehicles (EVs) has never been more popular than it is today. Millions of people around the world are already driving electric cars and by 2030, this number is expected to be a whopping 140 million.

While governments are creating new legislation and launching incentives to help the world shift towards electric mobility and car manufacturers are bringing more electric models to market, consumers and businesses are wondering what electric mobility means for them.  

One of the most noticeable shifts will be the way that we fill up our tanks, I mean batteries. Most drivers on the road today are used to filling up their tanks with fuel; they know exactly how far they can get by looking at their gas gauge, what it costs them to fill it up when it’s nearly on E, and which type of fuel they have to put in their tanks. 

When it comes to electric driving, this works differently. The places you can charge your vehicle are becoming far more diverse and the time it takes to charge can differ based on the level of charging and the type of vehicle. 

Initially, this may appear to be complex. This article is here to help, and explains everything you need to know about the different levels of electric vehicle charging.

What are the different levels of EV charging?

EV charging is divided into 3 levels; level 1, level 2, and level 3. Generally speaking, the higher the charging level, the higher the power output and the faster it will charge your electric car.

Simple right? Great. However, there are a few more things to consider. Before diving in deeper, it is important to understand the way EV charging stations are powered.

How are EV charging stations powered?

Without getting too technical, there are two types of electrical currents important when it comes to EV charging: Alternating Current (AC) and Direct Current (DC).

An electric vehicle charging cable plugged into a vehicle,  the socket is equipped with a LED screen that indicates the current status of the charge. In this case, the vehicle's battery is fully charged.

Alternating current vs. direct current

Alternating current (AC)

The electricity that comes from the grid and is accessible through the domestic sockets in your home or office is always AC. This electrical current got its name because of the way it flows. AC changes direction periodically, so the current alternates

Because AC electricity can be transported over long distances efficiently, it is the global standard we all know and have direct access to.

But that doesn't mean we don't use direct current. Quite the opposite, we use it all the time to power electronics.

Direct current (DC)

The electricity that is stored in batteries or used in the actual power circuitry inside electric devices is direct current. Similar to AC, DC is also named after the way its power flows; DC electricity moves in a straight line and supplies your device with power directly. 

Two graphs showing the way electricity flows. The first one shows how alternating current (AC) changes direction periodically, and the second graph shows how direct current (DC) flows in a straight line. AC comes from the grid and DC is stored in batteries.

So, for reference, when you plug an electric device into your socket, it will always receive alternating current. However, batteries in electric devices store direct current, so there is a conversion taking place inside your electrical device. 

When it comes to power conversion, electric vehicles are no different. The AC power that comes from the grid is converted inside the vehicle by an onboard converter and stored in the battery as DC electricity—where it powers your vehicle from.

Which type of current is used to charge my electric car? 

While Level 1 and Level 2 charging converts AC to DC via the vehicle's onboard converter, Level 3 charging supplies the battery with DC power directly. This is because the conversion of AC to DC charging happens outside the vehicle and in the charging station itself. Level 3 charging (also called DC charging or fast charging) cuts out the time-consuming conversion process and feeds the EV battery with the power it needs directly.

A visual that shows a DC charging station and an AC charging station both charging the same vehicle through different sockets. The vehicle shows its battery and onboard charger.

The difference between EV charging levels

What is level 1 charging?

This is the slowest (yet most accessible) way to charge an electric car. 

How does Level 1 charging work?

Level 1 charging is done by plugging the cord that came with your electric vehicle upon purchase into your regular wall outlet, or by getting a separate level 1 charger that you can mount to the wall. 

How fast is a level 1 charger?

Although charging times differ per vehicle and are dependent on other factors such as weather conditions, driving style, and the onboard battery converter, a level 1 charge will replenish your EV’s battery with about 4 to 5 miles range per hour (6 to 8 kilometers). So if you’ve driven 100 miles (160 kilometers), this means it will take you between 20 to 25 hours to fully charge your vehicle. 

What is level 2 charging?

Level 2 EV charging stations are usually found in public or commercial parking spaces, at the office, or in residential areas. These charging stations are a lot faster than level 1 chargers. 

How does Level 2 charging work?

Level 2 charging stations are separate stations that offer relatively fast charging speeds and can have a variety of additional smart functionalities. Installing a level 2 charging station has to be done by a professional. 

How fast is a level 2 charger?

Roughly speaking, it is about 5 to 15 times faster than a level 1 charger depending on the power output and the vehicle you’re charging. 

Charging for an hour with 7.4 kW will result in about 25 miles (40 kilometer) range, 11 kW in 37 miles (60 kilometers) range, and 22kW in 75 miles (120 kilometers) range. These calculations are approximations based on the average battery consumption of 18kWh per 62 miles (100 kilometers). Actual power consumption depends on the vehicle, battery size, and vehicle conditions. 

What is level 3 charging?

Level 3 charging (DC) is significantly faster than level 2 charging stations. Depending on the vehicle and power output of the level 3 charger it can take between 15 minutes to an hour to charge most electric cars—making it quick and easy to charge on the go. Because the power output needed for level 3 charging is a lot higher than for level 2 charging stations, they’re far more suited to commercial businesses like gas stations and you typically don’t see level 3 chargers installed at homes or office spaces.

How does Level 3 EV charging work?

Earlier, we explained that the battery inside an electric car only stores DC energy. So, this means that when using a level 3 charger, the conversion from AC (from the grid) to DC happens within the charging station itself. 

A level 3 charging station is typically quite large. This is because it needs to house substantial converters to be able to convert AC power a lot faster than regular on board converters inside electric cars. Some level 3 stations can provide up to 350 kW of power, and by doing so, charge an electric vehicle in about 15 minutes.

Why level 3 charging flows differently

These large converters and fast input of power also affects the charging flow. With level 1 and level 2 (AC) charging, the amount of power is delivered steadily and represents a flat line. This has to do with the fact that the onboard converter is relatively small and can only take a certain amount of power at a time. 

With level 3 charging, however, the charging line represents a quick peak before it gradually moves down. This has to do with the battery of the EV. At first, it will accept a quicker flow but as it fills up it will gradually ask for less power.

To illustrate this, imagine you're filling up an empty glass with water. When you start pouring water into the glass, you allow it to flow quickly, but as you get closer to the top you start slowing down to prevent the glass from overflowing. Level 3 charging works quite similarly, the empty glass is the battery and the DC charger is the bottle filled with water.

This is the reason why electric cars request less power once the battery is charged for 80 percent and why the final stretch of the charge is always a bit slower.

Two graphs showing the different charging curves of AC and DC. The first graph represents the curve of an AC charging station, It goes up rapidly, levels out quickly and moves in straight line before starting to decline near the end. The second graph represents the DC charging curve, showing a higher peak at the start of the charge, declining gradually on its way to roughly 80 percent where it starts to decline more.

The differences between level 1, 2, and 3 will ultimately affect charging times of a vehicle. If you want to learn more about the different levels and find the one that works best for you, your vehicle, and your needs, you can read more on home charging, business charging, or fast charging on our website.  

 

Learn what level 3 charging can mean for your business

Read our free ebook to get a complete overview of all fast EV charging possibilities, their differences, and what to look out for before investing.

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