Still Compatible with the Old GB/T Standard? Why Does the New Standard Jump to 800A? A Vehicle-Side Socket Selection Guide for Old vs. New Standards

The GB/T 20234-2023 series was officially released and implemented in September 2023, replacing the 2015 edition that had been in use for eight years. For vehicle and component engineers, the core changes boil down to three points: DC rated voltage raised from 1000V to 1500V, maximum charging current increased from 250A to 800A, and new requirements added for active cooling and temperature monitoring. The new standard maintains physical compatibility between old and new connectors so existing vehicles can continue charging, while providing a complete standards basis for 800kW-class high-power fast charging. This article reviews the differences across standard structure, rated parameters, new technical requirements, and test methods, and identifies what vehicle inlet selection teams need to adjust accordingly.

The 2015 edition consisted of three parts: Part 1 general requirements, Part 2 AC charging interface, and Part 3 DC charging interface. The 2023 edition replaces Parts 1 and 3 and adds a new Part 4, "High-power DC charging coupler," specifically covering liquid-cooled high-power scenarios. The AC interface part (Part 2) was not revised in this cycle. This structural change means high-power fast charging is no longer just a current rating tier within the DC standard, but a dedicated section with elevated requirements for cooling, temperature monitoring, and durability.

On ratings, the DC rated voltage ceiling rises from 1000V to 1500V, with 1500V established as a new preferred value; maximum charging current increases from 250A to 800A, supporting charging power up to 800kW. This parameter leap directly accelerates adoption of 800V high-voltage platform vehicles, and imposes new requirements on inlet contact materials, current-carrying design, and thermal structure.

The most significant new addition is the active cooling system. Under the 2015 edition, charging connectors relied on natural convection, and 250A was the practical upper limit for naturally cooled designs. The 2023 edition adds requirements for liquid-cooled medium cooling devices, thermal management systems, charging cables, and on-cable equipment, making 800A continuous charging feasible. In liquid-cooled designs, coolant circulates through the gun and cable to remove heat; the vehicle-side inlet must also provide a compatible thermal path and sensor mounting positions.

Paired with active cooling are new temperature detection requirements. The connector must include temperature sensors at key contact positions, monitoring temperature rise in real time and feeding data back to the charging control system. This transforms the vehicle inlet from a passive current-carrying component into an intelligent connection node with embedded temperature awareness. Sensor accuracy, installation location, and fault diagnostics all become mandatory test items under the new standard.

Beyond ratings and functional requirements, the new standard systematically refines test methods. On environmental adaptability, thermal cycling and alternating damp heat tests are added to verify reliability under extreme temperature swings and high humidity. On mechanical performance, locking device test methods are optimized and offset-operation tests are added to validate lock durability under misalignment conditions. On electrical performance, contact durability tests are added, and grounding conductor sizing and grounding measures are revised.

On inspection rules, a type-test plan is added, clarifying the division between routine and type tests and the corresponding pass-fail logic. Appendix B, "Temperature-rise test reference jig," is also newly added to standardize temperature-rise test boundary conditions and reduce inter-lab variability. For component suppliers, these changes mean longer validation cycles and more test items, requiring early planning of test resources.

Facing the new standard upgrade, vehicle inlet selection teams should evaluate four dimensions: first, whether rated voltage and current match the vehicle high-voltage platform—1500V system vehicles must select inlets rated per the new standard; second, whether temperature sensor mounting positions are reserved and temperature monitoring functionality is supported; third, cooling compatibility—liquid-cooled vehicle projects need to confirm whether the inlet has liquid cooling channels or a compatible thermal structure; fourth, certification status—whether the supplier product has completed type testing under GB/T 20234.3-2023 or .4-2023. Note that old and new interfaces remain physically compatible, so existing 250A vehicles can still charge normally, but new-platform models are advised to select new-standard-compliant products directly to avoid downstream certification and iteration risk.

DEGSON vehicle charging inlet products, the FGDC & AC series (natural cooling), are currently developed in accordance with the GB/T 20234-2023 new standard series. They support a maximum current of 300A and accommodate a 1000V voltage architecture, covering specifications for both DC charging interfaces and high-power liquid-cooled interfaces. Rated voltage, temperature monitoring interface, locking structure, and durability testing are all designed and validated to meet the new standard requirements. Specific models, certification status, and test reports are per official datasheets and third-party test reports; each vehicle platform still requires matching validation based on its own high-voltage system architecture.

Q1: After the new standard is implemented, can old-standard vehicles and chargers still be used?

A: Yes. The new standard upgrades on the basis of the existing DC interface technical solution and maintains universal compatibility between old and new connectors. Existing vehicles and chargers compliant with the 2015 edition can still physically mate and charge normally; they simply do not support the new high-power, liquid-cooled, and temperature-monitoring capabilities.

Q2: Does switching from an old-standard to a new-standard inlet require redoing full vehicle-level certification?

A: If the new inlet differs in rated voltage, current, or cooling method from the original design, re-validation and type approval for the onboard charging system are required. If it is a like-for-like replacement with identical physical interface dimensions, the scope of required supplementary testing can be determined through a change-impact assessment. We recommend confirming the change scope with the certification body during the selection phase.