Frequently asked questions
How does DC charging work?
There are two different types of EV charging stations: AC and DC. It's important to keep in mind that power from the grid is always AC and EV batteries only accept DC power. That means that at some stage, the current must be converted. The difference between AC and DC charging stations is whether that power convertor is located onboard or off-board the vehicle.
- AC delivers delivers alternating current (AC) to an AC/DC converter onboard the vehicle.
- DC charging stations convert AC before it reaches the vehicle, instead delivering direct current (DC) directly to the battery of an electric vehicle.
With DC charging, the convertor can be significantly larger due to the fact that it is located off-board the vehicle. Because the current is already converted to DC by the time it reaches the vehicle, it is possible to deliver more power, faster.
As a result of this different charging technique, DC stations can provide up to 350 kW of power and fully charge an EV in 15 minutes (providing the EV allows it). Due to their fast charging abilities, DC fast chargers are ideal for short-stop locations, fleet vehicle charging, and are beneficial for passenger vehicles as well as buses and trucks.
Want to find out more? Read our blog on the difference between AC and DC here.
How many kilowatts (kW) is a DC fast charger?
The kW output of DC fast charging stations varies depending on multiple factors including location, make, and model.
Broadly speaking, there are two different kinds of DC fast charging stations: standalone, and split.
- Standalone: comprised of a single unit, standalone charging stations can usually deliver between 50 kW and 250 kW of power.
- Split: charging stations with split architecture come with two main components—a user unit and a power unit—and usually deliver between 175 kW and 350 kW.
At EVBox, we have fast chargers that span from 50 kW all the way to 350kW.
Want to learn more? Check out this blog and take a closer look at DC charging.
How fast is it to charge with DC charging?
There are a number of factors which affect an EV’s charging speed with DC charging. However, because the AC/DC converter is located in the charging station itself, charging an electric vehicle with DC charging can be significantly faster than with AC charging.
Different factors which affect a vehicle’s charging speed with DC charging include the battery’s current charge, the weather conditions (batteries charge slower in the cold), the battery’s charging capabilities, and, of course, the power output.
Battery’s current charge: Due to measures to increase battery life and ensure safe charging, charging slows down significantly for the final 20 percent. As DC fast charging takes an EV's battery to 80 percent capacity in a comparatively short amount of time versus AC charging and then slows down for the remaining 20 percent, the time it takes for your battery to reach 100 percent full may be the same for the initial 80 percent charge.
Weather conditions: Depending on where you are charging your EV, the temperature may effect the charging speed. Cold temperatures can negatively impact charging speeds due to the fact that lithium-ion batteries—those used to power EVs—are very sensitive in low temperatures.
Power output: Obviously, the power output of the charger will have an effect on charging times. For example, 15 minutes of charging time can give you between 130 km and 480 km additional range at 100 kW and 350 kW output respectively. At 50 kW, one hour of charging a passenger vehicle will add an additional 278 km of range.
Additionally, we always say that the car is the “master” when it comes to dictating charging times. Some vehicles can accept more power than others. For example, while a Tesla Model 3 can accept 250 kW, a Nissan Leaf can only accept about 50 kW.
See this blog post for more information about how to make the most out of DC fast and ultra-fast charging.
Does DC charging work with all electric vehicles?
DC charging works with the vast majority of passenger vehicles. By default, EVs charge their batteries with direct current and this means that almost all accept DC fast charging. How much power each battery can handle, however, is another story. Some batteries can accept 350 kW whilst others can only accept 50 kW. Additionally, a very small portion of electric vehicles with smaller batteries do not have the capacity to charge with DC charging—for example, the Fiat 500 does not offer a fast charging capability. To get the most out of DC fast charging, it’s important to consider whether the EV supports DC charging, and if so, what is the maximum output that it accepts?
What kind of connector works with DC fast charging?
While almost all passenger vehicles can use DC fast charging, the process of charging itself may require a different connector than the one your vehicle uses with AC charging.
In North America, there are two standards for DC charging connectors—CCS and CHAdeMO—as well as Tesla’s proprietary Supercharger plug type.
Combined Charging System (CCS) allows for both AC and DC charging through the same input port, while vehicles equipped with CHAdeMO have a separate port for AC charging and can’t accept DC charging faster than 50 kW.
Due to this cap on CHAdeMO charging, CCS is becoming the dominant standard across Europe and North America and CHAdeMO is getting phased out across both continents.
That means that a CCS connector is likely to be necessary for DC fast charging in the future—at least in North America and Europe.
Does DC fast charging cost more than AC charging?
It is most likely that DC fast charging does cost more than charging your electric vehicle with AC power. When you’re paying for DC charging, you’re paying extra for the convenience to charge your vehicle quickly.
The difference in price, however, depends on the location which you charge and whether the charging station bills by the minute or by kWh.
Balancing price and convenience comes down to knowing what’s best for your vehicle. For instance, if your vehicle's maximum DC charging capability is 50 kW and you're occupying the ultra-fast charging station (250 kW), then you're going to be paying more whilst still receiving the same charge.
Ultimately, the answer is yes, DC fast charging costs more than AC charging, but it’s important to ask yourself, “do I actually need to charge this fast or is it more logical to charge slower?”
How do I find a DC fast charger?
DC fast charging stations are ideal for commercial and public locations, meaning that you’re likely to find them at retail and hospitality locations, in commercial parking stations, fuel retailers, highway rest stops, and utility providers.
To find a DC fast charger, Google Maps is a great option or you can always open one of the many EV charging apps available.