GB/T EV Connectors (China) - AC & DC Pinout, Wiring, CAN Protocol & Complete Specs
Complete guide to China's GB/T EV charging standards: GB/T 20234.2 (AC, 7-pin), GB/T 20234.3 (DC, 9-pin), CAN bus communication, power levels up to 900 kW with ChaoJi, and why China's EV charging ecosystem operates independently from the rest of the world.
GB/T EV Connectors (China). AC & DC Pinout, Wiring, CAN Protocol & Complete Specs
China is the world's largest EV market by nearly every measure. most vehicles sold, most charging infrastructure deployed, most battery manufacturing capacity. And China runs on its own charging standards.
The GB/T standards (GB/T = Guojia Biaozhun, 国家标准, "National Standard") are mandatory for all EVs sold and all public charging infrastructure built in China. There are two distinct connectors:
- GB/T 20234.2: AC charging, 7 pins
- GB/T 20234.3: DC fast charging, 9 pins
Neither is compatible with Type 1, Type 2, CCS, or NACS. China built a parallel ecosystem, and with over 10 million public charging ports (2025), it's the world's largest charging network. Understanding GB/T is essential for anyone working on vehicles, charging infrastructure, or energy systems touching the Chinese market.
GB/T 20234.2. AC Connector
Physical design
The GB/T AC connector looks superficially similar to the IEC 62196-2 (Type 2) connector used in Europe. it's round, roughly the same size, and has 7 pins. But the pin layout is different and they are not cross-compatible.
Rendering diagram...
AC pin assignments
| Pin | Name | Function |
|---|---|---|
| L1 | Phase 1 | AC power. single-phase hot leg (or three-phase L1) |
| L2 | Phase 2 | AC power. three-phase L2 (not used for single-phase) |
| L3 | Phase 3 | AC power. three-phase L3 (not used for single-phase) |
| N | Neutral | AC return / neutral |
| PE | Protective Earth | Chassis / safety ground |
| CC | Connection Confirmation | Plug presence detection (resistor-based, like PP in J1772/NACS) |
| CP | Control Pilot | PWM signaling for current limit (similar to J1772 / IEC 61851-1) |
AC control signaling
The CP (Control Pilot) signal uses the same PWM scheme as J1772 and IEC 61851-1 in concept, but with China-specific state definitions per GB/T 18487.1:
| CP state | Voltage (unloaded) | Meaning |
|---|---|---|
| State 1 | +12V DC | EVSE ready, vehicle not connected |
| State 2 | +9V PWM (±12V) | Vehicle connected, not charging |
| State 3 | +6V PWM | Vehicle connected, charging |
| State 4 | –12V | Fault |
The CC pin reads a resistor to ground in the vehicle inlet. Common values encode the cable current rating:
| CC resistor | Cable rating |
|---|---|
| 100Ω | 32A |
| 220Ω | 16A |
| 1000Ω | 10A |
AC power levels
| Configuration | Voltage | Max current | Max power |
|---|---|---|---|
| Single-phase | 220V | 32A | 7 kW |
| Three-phase | 380V | 32A | 21 kW |
| Three-phase (high power) | 380V | 63A | ~43 kW |
Most residential and public AC charging in China is single-phase 220V at 7 kW. Three-phase is common in commercial and fleet installations. The 43 kW three-phase option is the fastest AC charging available with GB/T.
AC wiring specifications
| Conductor | Cross-section |
|---|---|
| L1, L2, L3 (at 32A) | 4 mm² Cu minimum |
| L1, L2, L3 (at 63A) | 16 mm² Cu minimum |
| N | Equal to L conductors |
| PE | Equal to or greater than L conductors |
| CP | 0.5 mm² (shielded recommended) |
| CC | 0.5 mm² |
GB/T 20234.3. DC Connector
Physical design
The GB/T DC connector is larger than the AC version and dedicated to DC fast charging only. It has 9 pins in an arrangement that visually resembles CHAdeMO but is not compatible.
Rendering diagram...
DC pin assignments
| Pin | Name | Function |
|---|---|---|
| DC+ | DC positive | High-voltage DC positive power rail |
| DC– | DC negative | High-voltage DC negative power rail |
| PE | Protective Earth | Chassis safety ground |
| S+ | CAN-H | CAN bus high (communication) |
| S– | CAN-L | CAN bus low (communication) |
| CC1 | Charge connect 1 | Physical connection confirmation, handshake sequencing |
| CC2 | Charge connect 2 | Physical connection confirmation, interlock |
| A+ | Auxiliary 12V+ | Charger supplies 12V to wake vehicle BMS / low-voltage systems |
| A– | Auxiliary GND | Ground reference for the 12V auxiliary supply |
Key differences from other DC standards
Auxiliary 12V power (A+/A–): this is unique to GB/T. The charger supplies 12V DC on pins A+ and A– to power the vehicle's low-voltage electronics during the handshake phase, before the main DC bus is energized. This means the vehicle doesn't need an operational 12V battery to initiate charging. a pragmatic feature that prevents "dead EV" scenarios where a flat 12V battery prevents DC charging.
Dual connection confirmation (CC1/CC2): CHAdeMO has two sequence signals and CCS has one CP; GB/T DC has two separate CC pins. Both must read the correct resistance to confirm physical connection. This redundancy is part of why the GB/T standard has a strong safety track record.
CAN bus (like CHAdeMO, unlike CCS): GB/T DC uses CAN bus at 250 kbps for communication, not PLC. The protocol stack is simpler than ISO 15118 but protocol-incompatible with CHAdeMO.
GB/T DC. CAN Protocol
Message structure
GB/T DC communication uses CAN 2.0B frames at 250 kbps. The protocol is defined by GB/T 27930.
Rendering diagram...
Charging phases (GB/T 27930)
GB/T DC defines a structured handshake sequence more explicit than CHAdeMO:
Rendering diagram...
Key CAN messages
| Message | Direction | Contents |
|---|---|---|
| BRM | EV → Charger | VIN, battery chemistry, max voltage, pack capacity, SOC |
| CRM | Charger → EV | Charger ID, available DC voltage range, available current range |
| BCP | EV → Charger | Max charge voltage, max charge current, battery temp range, initial SOC |
| BCL | EV → Charger | Target voltage, target current for present 250 ms period |
| BCS | EV → Charger | Present battery voltage, present current, SOC, highest cell temp |
| BST | EV → Charger | Stop reason (SOC reached, fault, user stop, etc.) |
| CCS | Charger → EV | Present output voltage, present output current, remaining time |
| CST | Charger → EV | Stop reason from charger side |
The GB/T protocol sends the VIN (Vehicle ID Number) and battery chemistry in BRM. something CHAdeMO doesn't do. This has privacy implications (the charger knows exactly which vehicle it's serving) but enables better fleet management and diagnostics.
Power levels
GB/T DC power evolution
| Standard revision | Year | Max voltage | Max current | Max power |
|---|---|---|---|---|
| GB/T 20234.3-2011 | 2011 | 500V | 125A | 62.5 kW |
| GB/T 20234.3-2015 | 2015 | 750V | 250A | 187.5 kW |
| GB/T 20234.3-2023 | 2023 | 950V | 250A | 237.5 kW |
| ChaoJi (future) | future | 1500V | 600A | 900 kW |
Rendering diagram...
In the field, 120 kW and 180–240 kW are the most common fast charger ratings in China (2025). Ultra-fast chargers at 360–480 kW are being deployed for premium models (NIO, Li Auto, AITO/Huawei). These ultra-fast units use liquid-cooled cables and proprietary protocols layered on top of GB/T. similar to how Supercharger V4 extended CCS/NACS beyond its base spec.
Installed base (2025 snapshot)
China has approximately:
- ~11 million public charging ports
- ~3.5 million DC fast chargers
- ~7.5 million AC Level 2 slow chargers
The scale is staggering. roughly 10× the total public charging infrastructure of North America and Europe combined. This is why the rest of the world watches China closely: it's the largest real-world testbed for EV charging technology.
DC wiring specifications
DC power cable
| Power level | DC+ conductor | DC– conductor | PE |
|---|---|---|---|
| 62.5 kW (125A) | 25 mm² Cu | 25 mm² Cu | 10 mm² |
| 120 kW (170A) | 35 mm² Cu | 35 mm² Cu | 16 mm² |
| 187 kW (250A) | 50 mm² Cu | 50 mm² Cu | 16 mm² |
| 237+ kW (liquid-cooled) | 16 mm² Cu + coolant | same | 25 mm² |
Signal cable (inside DC cable)
| Wire | Pin | Size | Notes |
|---|---|---|---|
| CAN-H | S+ | 0.5 mm² | Twisted pair with CAN-L, 120Ω impedance |
| CAN-L | S– | 0.5 mm² | Twisted pair with CAN-H |
| CC1 | CC1 | 0.5 mm² | Connection detect 1 |
| CC2 | CC2 | 0.5 mm² | Connection detect 2 |
| A+ | A+ | 0.75 mm² | 12V auxiliary supply (charger → vehicle) |
| A– | A– | 0.75 mm² | 12V auxiliary ground |
| PE shield | . | Braid | Connected to PE in connector |
The 12V auxiliary pair (A+/A–) carries up to 5A in practice (60W budget for vehicle BMS startup). The wiring must be rated for 60°C minimum. Some charger manufacturers use 1.0 mm² for A+/A– to reduce voltage drop across the cable length.
Electrical characteristics
GB/T AC (20234.2)
| Parameter | Value |
|---|---|
| AC voltage (single-phase) | 220V, 50 Hz |
| AC voltage (three-phase) | 380V, 50 Hz |
| Max AC current | 63A (three-phase) |
| Max AC power | ~43 kW (three-phase 380V 63A) |
| CP signal | PWM, GB/T 18487.1 state machine |
| CC resistor values | 100Ω / 220Ω / 1000Ω |
| IP rating (mated) | IP44 |
| Operating temperature | –30°C to +50°C |
| Insertion cycles | 10,000 |
GB/T DC (20234.3)
| Parameter | Value |
|---|---|
| DC voltage range | 200–950V (2023 spec) |
| DC current range | 0–250A (passive cable) |
| Max power | 237.5 kW (passive, 2023) |
| CAN bus speed | 250 kbps |
| CAN bus protocol | CAN 2.0B, GB/T 27930 |
| Message rate | 250 ms (4 Hz) during charge loop |
| Auxiliary supply (A+/A–) | 12V DC, up to 5A |
| Insulation resistance | > 100 Ω/V |
| PE continuity | < 0.1Ω |
| IP rating (mated) | IP44 |
| Operating temperature | –30°C to +50°C |
| Insertion cycles | 10,000 |
| Emergency stop response | < 500 ms |
Safety features
GB/T's safety architecture shares philosophy with CHAdeMO but adds the dual CC confirmation:
-
Dual CC pins (CC1/CC2): both must confirm connection before any power. Single-point connection failure can't trick the charger into energizing.
-
Auxiliary 12V wakeup: A+/A– ensures the vehicle's BMS is fully booted before DC power is applied. No "charger tries to push power into a sleeping car" race condition.
-
VIN exchange in BRM: charger knows the vehicle identity. If voltage/current parameters in BCP don't match expected values for that vehicle, a reputable charger can cross-check.
-
BST/CST stop protocol: both the vehicle (BST) and charger (CST) have explicit stop messages with reason codes. Either party can stop the session; both must reach a mutually acknowledged stop state before power is cut and pins are released.
-
Insulation test: same as CCS and CHAdeMO. Mandatory before main contactor close.
-
Overcurrent and overvoltage protection: BCS messages include real-time battery temperature. If temperature exceeds the limits declared in BCP, charger must derate immediately.
-
CC interlock: connector cannot be removed while the DC contactors are closed. Hardware interlock monitored by CC1 continuity.
GB/T vs other DC standards
| Feature | GB/T DC | CHAdeMO | CCS2 | NACS |
|---|---|---|---|---|
| Communication | CAN bus (250 kbps) | CAN bus (250 kbps) | PLC (HPGP) | PLC (HPGP) |
| Protocol | GB/T 27930 | CHAdeMO spec | ISO 15118 | ISO 15118 |
| Plug & Charge | No (VIN but not cert-based) | No | Yes (ISO 15118-2) | Yes |
| V2G (bidirectional) | Emerging (GB/T spec in dev) | Yes (production) | Emerging | Emerging |
| VIN exchange | Yes (BRM) | No | Optional (ISO 15118) | Optional |
| Auxiliary 12V | Yes (A+/A–) | No | No | No |
| Dual CC pins | Yes | No (2 seq. signals) | No (1 CP) | No (1 PP) |
| Max deployed power | 237.5 kW | 150 kW | 350 kW | 500 kW |
| Future standard | ChaoJi (900 kW) | ChaoJi (shared) | CCS (900 kW spec) | J3400 (900 kW spec) |
| Global compatibility | China only | Japan + legacy worldwide | EU/US/Korea | North America |
ChaoJi. the successor
ChaoJi (超级充电) is the joint next-generation connector developed by the CHAdeMO Association and China Electricity Council. It's designed to:
- Replace both GB/T DC and CHAdeMO with a single new connector
- Handle up to 900 kW (1500V × 600A)
- Be physically smaller and lighter than either predecessor
- Carry native V2G (bidirectional) capability from the start
- Use a liquid-cooled cable as standard above 200 kW
Rendering diagram...
ChaoJi is not backwards-compatible with existing GB/T DC or CHAdeMO connectors. It's a clean-sheet design. Chinese EV manufacturers like BYD, NIO, SAIC, and the rest will need to add ChaoJi ports to vehicles or offer adapters when the time comes. Deployment timeline from China's government has been repeatedly pushed back. as of 2026, ChaoJi is still in field trial phase with no mass market launch date confirmed.
GB/T in the global market
China export vehicles
Chinese automakers (BYD, NIO, MG/SAIC, Geely/Volvo, Great Wall, Xpeng, Li Auto, AITO) are exporting vehicles in increasing numbers to Europe and Australia. Export models typically include both GB/T and CCS2 ports. GB/T for Chinese domestic market, CCS2 for international markets. Some models use multistandard charge ports with internal switching.
International adapters
- GB/T DC → CCS2: protocol-incompatible (CAN vs PLC). No simple passive adapter. Active protocol translation is available from third-party vendors for fleet applications.
- GB/T AC → Type 2: pin mapping is different, voltage and protocol are similar but not identical. Not direct-compatible.
- CCS2 → GB/T DC vehicle: same problem. active translation needed.
For personal use: if you have a Chinese-market EV and travel internationally, you typically need a vehicle that has a CCS2 inlet fitted from the factory, or a purpose-built adapter from the automaker.
Installation notes (China)
China's charging infrastructure is dominated by large charging operators:
- State Grid (国家电网). state-owned, largest network
- Southern Power Grid (南方电网)
- TELD (特来电). largest private operator
- Star Charge (星星充电)
- NIO Power: NIO's proprietary network (20-minute swaps + GB/T fast charging)
All public chargers must comply with GB/T standards mandated by the National Development and Reform Commission (NDRC). Chargers are typically networked with centralized billing. RFID cards, WeChat Pay, or Alipay, depending on the operator.
For new DC fast charge installations in China:
- Minimum 120 kW per port is now standard
- 240–360 kW per port common in commercial locations
- Liquid-cooled cable mandatory above 250A
- GB/T 27930-2015 or newer protocol required
- OCPP 1.6 or 2.0 for back-end management (increasingly common even in China)
GB/T is the gateway to the world's largest EV market. Whether you're an automaker, a charging operator, or an engineer designing bidirectional grid-tie inverters, understanding Chinese standards is no longer optional for anyone serious about the global EV industry.