NACS vs CCS - which one is better?

Most electric vehicles sold in North America use either the Tesla Supercharger or the CCS for fast charging. But what exactly is the difference between these two connectors? Does the type of connector affect the overall charging experience?

NACS (North American Charging Standard)

Image courtesy of Electrek

The North American Charging Standard (NACS) is based off Tesla's Supercharger network. Contrary to the popular belief that it is the same proprietary connector currently used by Tesla vehicles, the NACS is its slightly modified version. Instead of using the CAN bus, it uses power-line communication (PLC) and employs the same ISO 15118 protocol as CCS chargers do. This makes NACS chargers electrically compatible with any electric vehicle that uses a CCS connector.

In 2022, Tesla shared the design of its Superchargers with third-party manufacturers in a bid to make its proprietary connector the charging standard in North America. This came after a successful trial run of non-Tesla Supercharging in select European cities in 2019. While the NACS, more formally known as the SAE J3400, is still in the process of standardization by SA International, major carmakers including Ford, GM, and Rivian have all committed to fitting their EVs with the receptacle beginning in 2025.

NACS Pros

1. Enhanced Ergonomics: Tesla's NACS connector boasts improved ergonomics compared to CCS, featuring a smaller size and lighter cable. This design facilitates easier handling and connection, enhancing user convenience and efficiency during charging.

2. Reliability: NACS chargers are recognized for their reliability, with a significantly lower failure rate compared to CCS chargers. Studies indicate that only a small percentage of Tesla owners encounter major issues with the Supercharger network, demonstrating its consistent performance and dependability.

3. Increased Availability of Charging Ports: Despite having fewer station locations, NACS offers a higher number of public charging ports compared to CCS. Tesla's extensive Supercharger network provides nearly double the number of public charging ports, improving accessibility and reducing wait times for EV owners.

4. Simplified Charging Process: NACS chargers feature plug-and-charge capability, allowing EV owners to initiate charging seamlessly without the need for credit cards or mobile apps. This streamlined approach simplifies the charging experience, making it more user-friendly and straightforward.

NACS Cons

1. Limited Charging Locations: Despite offering more public charging ports, Tesla's Supercharger network has fewer charging locations compared to CCS. This limitation may pose challenges for EV owners in areas with limited charging infrastructure, affecting accessibility and convenience.

2. Slower Charging Speed: NACS chargers have a slower charging rate compared to CCS, with a maximum charging power of up to 250 kW. In contrast, CCS chargers can deliver up to 350 kW, enabling faster charging times for EV owners. This difference in charging speed may influence the charging preferences of EV owners, especially those prioritizing rapid charging capabilities.

Station locations and availability

Tesla's efforts to expand its Supercharger network, including upgrades to accommodate CCS-enabled EVs with the Magic Dock, signify a significant step towards interoperability and broader accessibility for non-Tesla EV drivers. Beginning March 2024, non-Tesla vehicles can now access 15,000 Supercharger stalls across North America, with “one new stall opening every hour”. While this is only available to Ford EVs for now, it will gradually extend to other automakers including GM, Polestar, Rivian, and Volvo in Spring 2024.

Ford has started registration for complimentary NACS adapters, available until July 1st, for the first 15,000 customers in the United States and Canada. Subsequently, the adapter will be purchasable for $230, in addition to applicable taxes and shipping fees. In line with this, Tesla has included a “Superchargers Open to NACS” filter in its charger locator. At the same time, the app now allows non-Tesla EVs to register and find charging stations compatible with NACS DC charging adapters. In the meantime, brands awaiting their adapters still have access to Tesla Superchargers equipped with Magic Docks.

CCS (Combined Charging System)

The Combined Charging System (CCS) is a standardized charging system specifically designed for fast-charging electric vehicles (EVs). It brings together both alternating current (AC) and direct current (DC) charging functionalities into a single connector, ensuring compatibility with a wide array of EV models. The foundation of CCS is the Level 2 AC charging connector, with the addition of two extra DC power lines, enabling it to support higher voltage compared to traditional connectors. Notably, when using a standard Type 2 charger, the bottom two holes on the connector remain unused as they are exclusive to the CCS plug.

In the United States, CCS connectors serve as the primary DC fast chargers deployed in public EV charging stations.

CCS Pros

1. Enhanced Charging Speed: CCS chargers provide a faster charging rate of 350 kW, outperforming Tesla's Superchargers rated at 250 kW.

2. Broad Industry Adoption: CCS technology is widely embraced by various automotive manufacturers such as Hyundai, Kia, Volvo, Mercedes-Benz, and Lucid. This widespread adoption ensures compatibility with a diverse range of EV models, improving accessibility and usability for EV owners.

3. Convenient Plug-and-Charge Functionality: CCS chargers feature plug-and-charge capability, streamlining the charging process and enhancing user convenience.

4. Expanded Charging Network: Although Tesla's Superchargers offer more charging ports, CCS charging stations are more widely distributed. This extensive network increases the likelihood of finding compatible chargers, enhancing convenience for EV owners.

CCS Cons

1. Bulkier Design: CCS chargers are notably larger and heavier compared to NACS counterparts, making them more challenging to handle. This bulkiness may slow down the charging process due to increased maneuvering difficulties.

2. Less Reliable Charging Stations: Reports suggest that CCS charging stations may be less reliable compared to Tesla's Superchargers. A 2022 study found only 72.5% of CCS charging ports in the Bay Area are operational. On the other hand, only 4% of Tesla owners reported difficulty in accessing its Supercharger stations.

3. Limited Charging Ports: Despite greater availability, CCS charging infrastructure offers fewer public-access charging ports compared to Tesla's Superchargers. This disparity in port availability may lead to longer wait times or increased competition for charging spots, particularly in regions with high EV adoption rates.

Station locations and availability

According to data from the US Department of Energy's Alternative Fuel Data Center, as of June 21, 2023, CCS charging station locations in the US outnumber NACS stations. There are 5,240 CCS charging station locations compared to 1,803 locations for Tesla Superchargers.

Despite the growing prominence of NACS, the transition away from CCS is expected to be gradual. Over the past decade, car manufacturers and charging companies have invested heavily in establishing CCS networks across the country. The adoption of CCS gained momentum with General Motors being the first automaker to utilize the fast charger on its EV. Subsequently, other automakers such as Volvo and Hyundai Motor Group embraced the CCS, contributing to its widespread acceptance.

Comparison between NACS and CCS

Both the CCS and NACS connectors are capable of charging EV batteries from 0 to 80% in under 30 minutes. However, finding out which charging standard is better involves evaluating several factors beyond charging speed alone. While both standards aim to facilitate efficient and convenient charging experiences, their differences in design, usability, compatibility, and impact on infrastructure play crucial roles in determining their overall effectiveness.

Differences in charger design and connector

Tesla's NACS plugs feature a smaller, lighter, and more compact design compared to CCS plugs. The Tesla connector is designed with user convenience in mind, featuring a funnel-like shape to facilitate easier plugging. Additionally, the NACS connector includes a button on the handle to open the charging port latch, further enhancing usability.

Image courtesy of Top Gear

CCS connectors typically feature long, thick, and heavy cables, making them more cumbersome to handle, especially in adverse weather conditions such as winter. The longer cables are necessary to accommodate varying charge port locations among different EV models, ensuring compatibility across brands.

Charging speed and power capabilities

While technically capable of delivering less power than CCS, Tesla's NACS connector still offers substantial charging speed, with a maximum output power of 250 kW. However, the charging speed of an EV is ultimately limited by its maximum charging input power. Tesla's NACS plug is limited to a maximum of 500 volts.

CCS connectors have a higher theoretical power output, with a maximum output power of 350 kW and the ability to deliver up to 1,000 volts. However, actual charging speeds may vary depending on the EV's maximum charging input power. For example, the Lucid Air, one of the fastest-charging EVs, has a maximum charging input power capped at 297 kW.

Compatibility with different electric vehicle models

Tesla vehicles, except for the Roadster, utilize NACS ports located in the left rear tail light. This standardized location allows for shorter and thinner cables with fewer maintenance requirements. However, its use of power-line communication (PLC) and the same ISO 15118 protocol as CCS chargers make it electrically compatible with CCS-enabled EVs. Compatible non-Tesla EVs need a NACS-to-CCS adapter to access Supercharger stations open to NACS.

Image courtesy of Rivian

CCS connectors accommodate EVs from various brands, as the standard does not specify the location of the charge port. This versatility ensures compatibility with a wide range of EV models, regardless of charging port location. Tesla owners wanting to charge at CCS chargers may do so using a CCS-to-Tesla adapter, provided that their vehicle is CCS-enabled.

Impact on charging network infrastructure

Tesla's Supercharger network is widely regarded as more reliable and extensive than other EV charging networks. With the largest fast-charging network in North America, Tesla offers more charging stations with NACS connectors compared to CCS plugs, enhancing accessibility for Tesla owners.

CCS charging infrastructure has a larger footprint compared to NACS, with more charging station locations in the US. Despite this, Tesla's Supercharger network remains highly regarded for its ease of use and dependability. Additionally, CCS charging stations may face reliability concerns, as evidenced by anecdotal evidence and studies highlighting operational issues.

Upcoming Developments

The widespread adoption of Tesla's North American Charging Standard (NACS) by major car manufacturers represents a significant move towards standardization within the electric vehicle industry. With SAE International's pivotal role in the development and recognition of NACS, the recent switch by Ford and GM to the NACS charge port, and plans to standardize the connector under the SAE J3400 umbrella, NACS is poised for formal recognition and commercialization, advancing interoperability and standardization in EV charging protocols.

Electrify America's announcement to include NACS connectors in its fast charging network reflects a broader trend towards promoting vehicle interoperability and simplifying public charging. As Electrify America continues to support the Combined Charging System (CCS-1) connector across its network while introducing the NACS connector, it emphasizes the industry's commitment to accommodating automakers integrating NACS charge ports.

On the other hand, the inclusion of CCS in the National Electric Vehicle Infrastructure (NEVI) program and government initiatives requiring car charging companies to incorporate CCS connectors demonstrate strong support for CCS technology in driving EV adoption in the US. Despite competition and alternative charging options, CCS remains the most widely used fast-charging standard for electric vehicles globally, reflecting its acceptance and adaptability within the electric motor industry.

Does the Connector Type Matter?

While both the CCS and NACS connectors facilitate fast charging, Tesla's minimalist NACS plug standard is often regarded as slightly better designed than the North American CCS1 connector. Vehicles equipped with NACS ports also benefit from access to Tesla's reliable charging network, although CCS connectors can deliver higher current and voltage. However, advancements such as Tesla's V4 Superchargers may influence future charging capabilities.

Notably, bidirectional charging technology, essential for certain EV functionalities, is currently limited to options with CCS connectors, except for the Nissan Leaf, which utilizes CHAdeMO. Tesla plans to introduce bidirectional charging capability to its vehicles by 2025 with the highly anticipated Cybertruck, expanding options for consumers.

With backing from prominent players, NACS is poised to take the crown from CCS. Once officially standardized by Fall 2024, its widespread adoption by prominent automakers, coupled with its existing popularity and the backing of Tesla's extensive charging infrastructure, positions NACS to potentially surpass CCS as the preferred standard for electric vehicle charging.