Analysis
28 Feb 19

The good, the bad and the ugly of DC charging

It is fast, tremendously fast, so, why are we not all charging our EV at a DC fast charger? Let’s face the good, the bad, and the ugly of DC fast charging.

How fast?

First of all, let’s define a DC fast charger or level 3 charger. Most EVs are charged at home or at free public charging stations where they are topped up AC (alternating current), which has to be converted via the internal EV charger into DC (direct current) so the car can drive on it. 

Moreover, most of these public chargers are limited to 240-volt, or level 2 charging, while home chargers can even be limited to 110-volt, or level 1 charging. A DC fast charger on the other hand takes the charging level way beyond these limits, and provides the quickest charging system.  

The good

This is the bright side of DC fast charging. Without a doubt, the main advantage of a super charger is the speed of charging. While loading your EV at home at a level 2 charging point takes you the entire night, with a level 3 charger the task can be done in less than an hour. Good for those who are often on the road and need a quick refill every once in a while. It's important to know, however, that the EV battery will only be loaded up to 80% since the last part should preferably be loaded at a lower capacity – level 2 charging – to protect the battery. 

The bad

Level 2 charging points are the most common and it will probably be harder to find a DC fast charger. Also, you will definitely not find it at home. However, the good news is that a couple of websites and smartphone applications provide you with interactive maps to locate superchargers, even if they are occupied at that moment. Since it only takes you an hour, this indication makes more sense than in the case of a level 2 charging point, where an EV can be stuck for a couple of hours. 

Further on, more initiatives have been expanding the number of level 3 charging stations across America. There is already the EVgo network with more than 1,100 public fast chargers across 66 metropolitan areas in the US. Electrify America is planning 2,000 DC fast chargers across 17 cities in 40 states. While one of the charging points market leaders, ChargePoint, actually only plans about 1,000 superchargers, compared to its 60,000 charging points across the US.

The ugly

So, you’ve reached the fast charger, but that speed comes at a price. First of all, to access the charging station you need an access card or a smartphone application of one of the charging networks. These charging sessions now are limited in time, because the battery should not be loaded up to 100% at fast charging speed. Instead, the last 10 to 20% should be charged by level 2 charging anyways. 

And they are expensive, in contrast to many level 2 chargers where you can charge for free. You’ll pay either per charged time or per charged kW, depending on the charging station. For instance, a 30 minutes charge at a DC fast charger in the Chicago area would cost about $8.70 for 80 miles. This would cost you $2,75 to drive 25 miles, while it would cost you less than a dollar if you would charge the EV at home, which becomes a big difference if you drive a lot of miles. 

Since carmakers are aware of this high price, there are several ways to get a better rate. For instance, some charging stations offer a discount when paying a monthly up-front fee. Other OEMs have deals with certain charging networks, allowing you to charge your EV for a certain period for free or at better rates. Tesla, however, has reviewed its free access policy for its Supercharger network. 

One more thing you should know, whereas level 2 outlets are more uniform, level 3 chargers come with a wide array of connector configurations. Depending on its origin, you might need another connector, so beware. Most German and American originated EVs use the SAE Combo plug, whereas most models of Asian OEMs use a CHAdeMO connector. In addition, Tesla has its own type of connector to access its own Supercharger network.

However, with an adaptor you could charge your Tesla at CHAdeMO or SAE Combo plug systems as well. Fortunately, the information on the dedicated connector of the supercharger stations can be found in those charging point stations location applications as well. 

Beauty and the Beast

In the end, the DC super charger is both, the beauty and the beast. It is fast in its speed, but speed comes at a price and the network is not widespread yet. So, for those who are willing to pay and look around, feel free to take it for a dance.

Authored by: Fien Van den steen
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