As electric vehicles (EVs) take over the roads, the need for faster, more efficient charging infrastructure has never been more apparent. While most EV charging is still done at home, the normal residential electricity supply limits charging output, usually between 3kW and 19kW for Level 2 chargers. This translates to 18-28 miles of range per hour, enough to fully charge an average EV overnight.

However, on the road, EV drivers expect quick top-ups between stops. And that’s where DC fast chargers come in.

What is DC Fast Charging?

Image courtesy of InsideEVs

DC fast charging, or direct current fast charging, allows electric vehicles to charge their batteries at a much higher rate than standard AC charging. Unlike AC charging, which is suitable for overnight or slow charging at home, DC fast charging is designed for rapid top-ups on the go. Here's how DC fast charging works:

1. Conversion to DC: DC fast charging stations provide a direct current (DC) supply, which is the type of electricity stored in EV batteries. The onboard charger in the vehicle converts this DC power into a form that can charge the battery.
2. High Charging Power: DC fast chargers can deliver a much higher charging power compared to AC chargers. This high power enables faster charging rates, making it possible to add a substantial range in a short amount of time.
3. Wide Compatibility: DC fast charging is compatible with a wide range of electric vehicles, as long as they have the necessary connectors, such as CCS or CHAdeMO.
4. Charging Speed: Charging speed with DC fast charging can vary based on the charging station's power rating and the EV's capabilities. The highest-power stations can charge a compatible EV from 10% to 80% in under 30 minutes.

Currently, in North America, there are three types of DC fast charging: CHAdeMO, Combined Charging System (CCS), and Tesla Supercharger, with CCS being the most widely used.

What is CCS?

The CCS, or Combined Charging System, is a standardized fast charging system for electric vehicles. The CCS connector takes the J1772 charging inlet and includes two extra pins below it. As the name suggests, it combines the J1772 connector with the high-speed charging pins. It has become increasingly popular due to its versatility, supporting both AC (Alternating Current) and DC (Direct Current) charging, making it a convenient choice for various EVs. When it comes to fast charging, CCS is capable of delivering high charging speeds, but the actual rate depends on several factors:

Charging Power

The charging power is a crucial factor in determining how fast you can charge with a CCS. CCS charging stations can provide different power levels, typically ranging from 50 kW to 350 kW or more. The higher the power, the faster the charging rate. Modern EVs, especially those designed for long-range driving, are equipped to handle higher charging powers, allowing for quicker charging.

Vehicle Compatibility

The charging speed also depends on the compatibility of your electric vehicle. Some older EVs may not support the highest charging speeds offered by CCS stations, while newer models are designed to take full advantage of the available power.

State of Charge

The state of charge (SoC) of your EV's battery can affect charging speed. Charging is generally faster when the battery is at a lower SoC. As the battery fills up, the charging rate may decrease to protect the battery and maintain its health.

Temperature

Temperature can significantly impact charging speed. Extremely low or high temperatures can reduce the efficiency of the battery and charging process, leading to slower charging rates.

Typical Charging Times with CCS

To provide a general idea of how fast you can charge with a CCS, here are some approximate charging times for various EVs using a 350 kW CCS charger:

• Tesla Model 3: Approximately 20-30 minutes to reach an 80% charge, which is typical for many long-range electric vehicles.
• Ford Mustang Mach-E: A similar charging time of around 20-30 minutes for an 80% charge.
• Audi e-tron: Approximately 30-40 minutes to reach an 80% charge.

Keep in mind that these are approximate times and can vary based on the factors mentioned earlier, including charging power, vehicle compatibility, state of charge, and temperature conditions.

While Tesla EVs have access to an exclusive DC fast charging network (Superchargers), CCS-compatible models can still use CCS chargers with the Lectron CCS to Tesla EV Adapter. This adapter has a charging rate of up to 150 kWh with a maximum rating of 500V and 300A.

As for non-Tesla owners looking to access Superchargers, Tesla recently started rolling out the Magic Dock as part of its initiative to promote fast charging. North American Charging Standard (NACS)-compliant carmakers such as Hyundai, BMW, Toyota, and Kia can also use third-party adapters like the Lectron Vortex Plug to gain access to 25,000+ Tesla Superchargers across the country.