EV Charging Interface Standards (National Standard GB/T)

EV Charging Interface Standards (National Standard GB/T) refers to a series of national standards issued by the Standardization Administration of China to govern the physical connections and communication protocols between electric vehicles and charging infrastructure. Centred around GB/T 20234 "Connection set for conductive charging of electric vehicles", these standards define the physical dimensions, contact pin assignments, rated parameters, and technical requirements of charging interfaces, serving as the foundational benchmark to ensure charging infrastructure interoperability as well as safe and dependable charging.

Evolution of the Standards

The development of China's EV charging interface standards spans four distinct phases, progressing in step with the expansion of the nation's new energy vehicle industry.

Inception and Early Standardization Phase (2006–2010). In 2006, China published GB/T 20234-2006 "General requirements for plugs, socket-outlets, vehicle couplers and vehicle inlets for conductive charging of electric vehicles". This marked China's first standardisation effort in the new energy vehicle charging sector. However, it lacked comprehensive specifications regarding exact structural dimensions and pin definitions, resulting in compatibility issues across early market hardware.

Physical Interface Unification Phase (2011–2014). The rollout of the GB/T 20234-2011 series in 2011 unified the physical dimensions and hardware structural definitions of AC and DC charging interfaces for the first time. It clearly defined a 7-pin design for AC charging interfaces and a 9-pin design for DC charging interfaces, alongside detailed specifications for each pin function. Concurrently, GB/T 27930-2011 established the vehicle-to-charger communication protocol framework for DC charging, successfully addressing the fundamental requirements of physical fitment and rule-based digital communication.

Comprehensive Standardisation and Interoperability Phase (2015–2022). The 2015 revision proved to be the most influential. GB/T 20234-2015 comprises three parts: Part 1 General requirements, Part 2 AC charging coupler, and Part 3 DC charging coupler. This version refined interface electrical ratings, mechanical dimensions, and safety architectures while introducing electronic locking mechanisms, effectively driving the nationwide rollout and mass adoption of China's charging infrastructure. The current AC charging interface standard continues to be based on this version.

High-Power Fast Charging and System Refinement Phase (2023 to Present). On 7 September 2023, GB/T 20234.1-2023 and GB/T 20234.3-2023 were officially released. Retaining the 2015 interface architecture to ensure backwards compatibility, these standards raised the maximum charging current from 250A to 800A and elevated charging output to 800 kW, incorporating technical requirements such as active liquid cooling and thermal monitoring. Released concurrently, GB/T 20234.4-2023 "High power DC charging coupler" addresses ultra-fast charging applications, catering to operating voltages up to 1,500V and rated currents up to 800A.

Technical Specifications

The key technical parameters of the active GB/T 20234 series standards are detailed below:

AC Charging Interface (GB/T 20234.2-2015): Rated voltage not exceeding 440V (AC) at 50Hz, with a rated current of up to 32A (AC). The interface utilizes a 7-pin layout.

DC Charging Interface (GB/T 20234.3-2023): Rated voltage not exceeding 1,500V (DC), rated current up to 800A (maximum continuous operating current), featuring a 9-pin layout.

General Requirements (GB/T 20234.1-2023): Outlines comprehensive specifications covering AC connection sets (rated voltage up to 690V, current up to 250A) and DC connection sets (rated voltage up to 1,500V, current up to 1,000A).

Relationship with the ChaoJi Standard

GB/T 20234.4-2023 is closely linked to the China-led ChaoJi charging technology. Following years of R&D and validation, the ChaoJi standard was adopted by the International Electrotechnical Commission (IEC) as a global general specification. Nonetheless, the GB/T 20234.4 interface is physically incompatible with the standard 2023-edition interface. Both are also overseen by different governing bodies: the former is managed by the China Electricity Council, whereas the latter falls under the Ministry of Industry and Information Technology.