The difference between NACS and CCS

NACS Overview

The NACS(Tesla) charging protocol was introduced in 2008 for Tesla’s electric vehicles. It utilizes a unique connector design with liquid-cooled cables for high 400V DC fast charging up to 250kW. As an older standard, NACS has limitations in max power delivery compared to newer protocols. But its reliability and convenience for Tesla owners is unmatched.

CCS Explained

The CCS(Combined Charging System) combines single-phase AC charging and fast DC charging in a single connector. Introduced in 2009 and compliant with the SAE J1772, CCS has become the standard for most non-Tesla EVs with support up to 920V and 350 kW charging. CCS uses dedicated DC pins for high-power charging compared to repurposed AC pins in NACS.

Connector Design Differences

NACS uses a proprietary connector design with a single liquid-cooled charging cable for both AC and DC charging in one port. In contrast, CCS utilizes the J1772-2009 AC connector standard with two additional DC pins at the bottom not present on AC chargers. This allows backward compatibility with existing AC charging infrastructure.

Communication Protocols

The NACS protocol is proprietary to Tesla. CCS utilizes the ISO 15118 high-level communication protocol between EV and charger for safer charging compared to NACS. ISO 15118 allows smart charging capabilities adjusting to grid demands. NACS lacks such abilities for vehicle-to-grid integration.

Public Infrastructure Availability

As Tesla’s connector is proprietary, NACS charging infrastructure is currently only available for Tesla drivers. Whereas CCS fast charging stations are widely deployed across public networks like Electrify America accessible to all new EV models besides Tesla. CCS aims for interoperability between automakers.

Max Charging Capability

Early NACS chargers were limited to 90 kW which has expanded to 250 kW in its latest iteration. However, new CCS chargers already support charging power up to 350 kW allowing faster charging. As EV battery capacities grow, CCS charging speeds will remain superior in meeting demanding peak charging needs.

Charging Efficiency

NACS’s liquid-cooled charging cables allow very high electrical efficiency with little energy converted to heat at high currents. CCS does not require liquid-cooling for today’s EVs but for next-generation batteries efficient cooling in cables will be critical to avoid energy losses.

Safety Features

Lacking the ISO 15118 protocol, NACS provides less native safety compared to CCS during charging. While both use control pilot circuits, CCS offers more robust shocked protection on the DC pins using micro relays. CCS also guarantees Plug-and-Charge security features.

Upgradeability

As an older standard, NACS has limitations in future-proofing to support next-gen EVs. The CCS connector contains reserved pins giving it headroom for upgrades to 600A+ charging if needed. NACS is largely fixed in its current implementation without flexibility for enhancements.

Global Standardization

CCS has seen broad adoption beyond Europe and NA as the charging standard for global automakers in China and elsewhere driving economies of scale in production. With CCS poised as the global plug standard for non-Tesla EVs, NACS will continue having niche regional use for Tesla drivers only limiting its growth.

FAQs

What are the key differences between the NACS and CCS EV charging standards?

NACS is a proprietary standard used only by Tesla vehicles with unique connectors while CCS uses the SAE J1772 plug with additional DC pins for compatibility. NACS maxes out at 250 kW charging currently while the latest CCS supports up to 350 kW for faster charging.

Which charging standard is more widely deployed for public charging?

CCS has seen rapid public charging infrastructure deployment across networks like Electrify America whereas NACS/Tesla connectors are only available on Tesla’s network for their owners. CCS aims for interoperability between automakers.

Is one standard safer or more efficient than the other?

CCS offers native communication protocols and robust safety measures where NACS lacks in those areas slightly but makes up through high efficiency with liquid-cooled cables. CCS will need similar cooling needs in next-gen vehicles.

Which standard is more future-proof as EV battery tech evolves?

CCS is designed with reserved pins and upgradability to 600A+ charging allowing headroom to evolve with new battery tech. It also enjoys economies of scale in production from global standardization that NACS may struggle with long-term.

Will Tesla eventually switch to the CCS standard?

While not confirmed, it is possible though unlikely in the near future. The proprietary advantages Tesla retains with its connector and charging platform will probably outweigh any benefits from adapting CCS unless a clear strategic need emerges.