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DC Fast Charging

DC fast charging is a technology that considerably speeds up the process and makes the waiting time for recharging an electric vehicle shorter and shouter.

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Now that electric mobility is a reality, a second concern comes to mind: If you have to wait for the battery to charge in the middle of a trip. Is an electric car worth it? How long does it take to complete the recharge?

We will investigate the secrets of fast charging for electric cars to resolve these doubts. Direct current (DC) is an important point that allows us to talk about fast charging in electric vehicles. Public charging stations, which are spreading more and more rapidly, now have direct current chargers, classified as fast chargers. Know all the details about DC charging!



I. What is DC Fast Charging?


What is DC Fast Charging


DC or direct charging is also known as a Fast Charger (DC). This charger can charge a vehicle’s battery for up to 5 or 10 minutes, depending on the power, in so-called “ultra-fast” charges. It supplies energy directly to the batteries. There are 3 main types of EV chargers, known as level 1, level 2, and level 3 or 4, which are classified according to the charging time and power they can supply. Fast chargers belong to level 3/mode 4 and operate on direct current (DC). They supply between 20 and 300kW and can charge a vehicle in about 10min (in DC regime).



II. What kind of Connector Works with DC Fast Charging?


Combined Charging System(CCS)

More and more electric vehicles hit the market with a new type of combined connector called CCS Combo, which allows the car to use slow, semi-fast, and fast charging points. Vehicles with this type of connection can currently accept a charging speed of up to 50kW, although work is already underway to use powers of 150kW or higher. This is the fast charging standard used by European manufacturers.


The CHAdeMO standard is based on a connector, which is bulkier and more difficult to handle than the CCS/Combo, generally only available on Asian vehicles. In its first specification, the maximum charging power is 500V DC and 125 amps (62.5 kW), although commercial chargers are typically limited to 50kW or less. This connector is not always standard on electric vehicles, so it may have to be included as an option.

Tesla Supercharger

Only Tesla has superchargers that can charge up to 120kW, but these are conditioned to their customers by the company’s internal protocol. Currently, with its 120kW superchargers, Tesla is the only company on the market that allows charging as fast as possible, 80% in 30min (the EV has a range of around 380km). The remaining vehicles are still limited to 50kW charging due to the characteristics of their batteries.



III. How does DC Fast Charging Work?


DC Fast Charging avoids all of the constraints and weaknesses of the on board charger and essential conversion. It depends on the battery size and the output of the dispenser. Mode 4 or level 3  is a more powerful charging unit (usually up to 50kW) that supplies direct DC power to the vehicle. In DC fast charging, the charging cable is connected to the charger. There are several types of quick charge connectors,  but DC used the three hoses charger with the corresponding connector, two on the vehicle side (CHAdeMO and CSS/Combo 50kW) and one on the charging point side.



IV. What is the Difference between AC and DC?


AC charging is the simplest type of charging to find. Power outlets are everywhere. Nearly all-electric vehicle chargers found in homes, shopping malls, and workplaces are Level 2 AC chargers. AC charger provides power to the vehicle’s onboard charger, converting that AC power to DC for input to the battery.

DC fast chargers are electric vehicle chargers that come in levels 3 based on voltage. At 480 volts, the DC Fast Charger can charge your electric vehicle faster than a Level 2 AC charging station. For example, an electric car that would take 4 to 8 hours to charge with a level 2 AC charger will normally only take 15-30 minutes with a DC fast charger. DC This is mainly high in cost of both the product and the installation than AC charging.



V. How Fast is it to Charge with DC Charging?


The charging speed you can get at a DC fast station depends on the station’s power level. Recharging in Mode 4 ( DC charging) is the one that is carried out at a station outside our home and allows us to recharge at least 80% of the battery in less than 30 minutes. We must distinguish between mode 4 with ‘super fast’ reloading and mode 4 with ‘ultra fast’ reloading. The latter is not recommended for daily charging since it can damage the battery if we use it regularly. It is specially designed for outdoor public use stations such as charging stations, where we can recharge the vehicle during long journeys or specific situations in which we have little time.

The charging time varies greatly depending on the power of the charger and the batteries of each vehicle. To take some average references, and taking as an example a car with a 40 kWh battery for a recharge of 80% of its total capacity, the charging times would be:

  •         For quick recharge: 30 minutes.
  •         For super-fast recharge: 15 minutes.
  •         For ultra-fast recharging: 5 to 10 minutes.



VI. Fast Charging When you Really Need it Most


Fast Charging When you Really Need it Most


DC fast charging electric car stations are now at public access and are usually located at strategic points, such as highways. You can fast charge your electric vehicles to reach quickly where you are going or on long trips, highways, and ways to remote places or when you are hard pressed for time. Although the reduced charging time is one of the advantages of level 3 or mode 4 chargers, which are 50 kW of power and above, many experts say that their frequent use is not recommended as it reduces the timing and life of the battery.



VII. Follow the 80% Charging Curve Rule


All-electric cars and their batteries have an ideal charging range. The charge slows down when it reaches 80%, so many manufacturers tell you about periods of just half an hour to go from 0 to 80% charge. The remaining 20% ​​is an entirely different story. In fact, many manufacturers do not provide owners with the full load curve. Although an electric car admits maximum charging powers of up to 150 kW, that does not mean that such capacity will be reached during the entire process. It is impossible to get peak power at some point in the charging process as it heats the battery.

If you are using a DC fast charger, it is better to disconnect when your car battery goes about charging 80% because otherwise, charging gets severely slow. Your battery could take almost as long to charge the last 20% as it took 80%. If you try to charge 100%, it will decrease the car’s efficiency.




DC fast charging is way faster than Level 2 or (AC) charging. It is handy and effortless to use. It is a technology that considerably speeds up the process and brings the waiting time for recharging an electric vehicle closer and closer to the time it takes to refill the fuel tank. The perfect time to take advantage of DC fast charging is when you have to charge your electric vehicle right away, and also, you are ready to pay a bit more than usual for the convenience. Finally, if you want to make the best out of DC charging, consider whether your EV can support DC charging and what is the highest output it takes.