The global electric vehicle (EV) market has seen rapid growth, accompanied by the development of various charging standards across different regions. Understanding these standards is crucial for compatibility and efficiency in EV charging infrastructure. Globally, charging standards are mainly categorized by charging method and national standards.
By Charging Method
Charging methods can be broadly classified into three types: Direct Current (DC) charging, Alternating Current (AC) charging, and hybrid AC/DC charging stations. DC and AC charging are the most common methods, with DC generally offering faster charging speeds. Regular charging (slow charging) and rapid charging (fast charging) differ in speed due to various factors such as vehicle battery capacity and ambient temperature. Slow charging typically takes 5-10 hours to fully charge a battery, while fast charging can achieve an 80% charge in about 30 minutes and a full charge within an hour.
By National Standards
Globally, there are five main charging standards, categorized by regional or national adoption: American Standard, European Standard, Japanese Standard, and Chinese National Standard (GB).
American Standard (CCS1)
The American standard is primarily followed by Tesla, a pioneering electric vehicle brand in the US. Tesla has developed its own charging standard, with wall-mounted AC charging stations offering 10 kW and 21 kW options, and “Supercharger stations” providing up to 125 kW of power, with ongoing improvements in charging power.
European Standard (CCS2)
The European standard seeks to unify EV charging connectors across Europe, much like the Euro currency. The EU standard incorporates both AC and DC charging methods, with a three-phase AC charging at the top and a large circular hole at the bottom for DC charging. The Combo DC fast charging can charge an EV with a range of 350 kilometers in just 30 minutes, supported by European brands such as BMW, Mercedes-Benz, and Audi.
Japanese Standard (CHAdeMO)
The Japanese standard, known as CHAdeMO (meaning “very fast” in Japanese), can output up to 50 kW of power. Currently, Japanese brands like Nissan and Mitsubishi use this charging connector for their electric vehicles.
Chinese National Standard (GB)
The Chinese National Standard, familiarly known as the GB standard, is universally adopted in the Chinese market. The power range varies from 15 kW to 380 kW, catering to different usage scenarios including liquid-cooled and air-cooled charging stations. Recently introduced energy storage charging stations also comply with this standard.
Tesla Charging Standard
In the United States, the commonly accepted charging standard is J1772, with the notable exception of Tesla, which has developed its proprietary charging interface for Tesla electric vehicles. On November 11, 2022, Tesla announced its own NACS standard and welcomed its widespread use.
NACS is a combined AC/DC socket, which, due to interface limitations, cannot accommodate three-phase AC power. This limitation means that it cannot be used in countries or regions that utilize three-phase AC power, such as China and Europe.
The interface circuit of NACS is identical to that of the CCS, meaning that the vehicle’s onboard control and monitoring unit (OBC or BMS) circuitry, originally designed for the CCS standard, does not require redesign or layout changes to be fully compatible with NACS. This compatibility is advantageous for the promotion of NACS.
Furthermore, there are no restrictions regarding communication; it is fully compatible with the requirements of IEC 15118.
NACS supports a maximum voltage of 1000V DC and a maximum current of 400A DC; the AC component is consistent with J1772.
Conclusion
Understanding these global charging standards is vital for ensuring the compatibility and efficiency of EV charging infrastructure. As the EV market continues to grow, the need for standardization and interoperability among different charging systems becomes increasingly important. This will not only facilitate international EV adoption but also improve the user experience by making EV charging more accessible and convenient worldwide.
