Plug an electric car into a fast charger anywhere in China and you use the same connector: the big round plug with two thick power pins and seven small ones. Its shape, its pins and its limits are set by one standard: GB/T 20234.3.
The current edition is GB/T 20234.3-2023. It lets the same connector carry far more power than before, and it makes a lock on the plug compulsory. If you make chargers, cables, vehicle inlets or electric cars for China, this is your reference.
In short
- What it is
- Part 3 of GB/T 20234: the DC charging coupler (vehicle plug and vehicle socket) for electric vehicles
- Limits
- Up to 1,500 V DC and 800 A
- Pins
- 9 on each side: power, earth, communication, connection check, auxiliary power
- New in 2023
- Higher voltage and current · mechanical lock required · small change to the CC2 pin
- Dates
- Issued and in force September 7, 2023
- Replaces
- GB/T 20234.3-2015
What is GB/T 20234.3?
GB/T 20234 is a family of standards for charging plugs. It has these parts:
- Part 1 — general requirements for all charging plugs and sockets (GB/T 20234.1-2023)
- Part 2 — the AC charging plug (slow charging)
- Part 3 — the DC charging plug (fast charging): this article
- Part 4 — the new high-power DC plug (GB/T 20234.4-2023)
Part 3 defines the shape and size of the plug and socket, what each pin does and the order in which the pins touch. The test methods come from Part 1. The "language" the charger and the car speak over the communication pins comes from a separate standard, GB/T 27930.
The /T means the standard is recommended, not mandatory by law. In practice, almost every DC charger and electric car in China uses this connector, because the whole point is that any car fits any charger.
What changed from the 2015 edition?
| Topic | GB/T 20234.3-2015 | GB/T 20234.3-2023 |
|---|---|---|
| Maximum voltage | 1,000 V | 1,500 V (ratings of 750, 1,000 and 1,500 V) |
| Maximum current | 250 A | 800 A with active cooling |
| Locking | Less detailed | Mechanical lock required; electronic lock and emergency release recommended |
| CC2 pin in the car socket | Old height | New height of the CC2 pin sleeve |
| Lock examples | None | New drawings of lock designs (clause 10) |
What did not change matters just as much: the connector keeps the same basic shape and pin layout, so it still works with the millions of cars and chargers already in use. The standard says so in its introduction: compatibility with existing vehicles and charging stations is a requirement.
How much current can it carry?
The standard lists current ratings in two groups:
| Cooling | Rated currents |
|---|---|
| Natural cooling (no fan, no liquid) | Up to 300 A |
| Active cooling (usually liquid-cooled cables) | Up to 800 A |
Table 1 of the standard gives the full list of rated current steps in each group.
The rated current is the highest current the whole connector, cable included, can carry continuously once the plug is fully in. For short periods the current can be higher. During charging it is adjusted all the time, based on the temperature of the contacts and the cooling system.
A quick example: at 1,000 V and 250 A, the old limits, a connector can pass up to 250 kW. At 1,000 V and 600 A, now allowed with cooling, that becomes 600 kW. The car's battery and the charger decide how much power is really used. The connector is no longer the bottleneck.
What do the 9 pins do?
| Pin | Name | What it does |
|---|---|---|
| 1, 2 | DC+ and DC− | Carry the charging power to the battery |
| 3 | PE | Protective earth: connects the charger's earth to the car body |
| 4, 5 | S+ and S− | CAN communication between charger and car |
| 6 | CC1 | Connection check, read by the charger |
| 7 | CC2 | Connection check, read by the car |
| 8, 9 | A+ and A− | Low-voltage power from the charger to wake up the car's systems |
Why the order of the pins matters
The pins do not all touch at the same moment. The standard fixes the exact order in which they make contact when you plug in, and the reverse order when you unplug. Two rules carry the safety idea: earth is always the first pin in and the last pin out, and the charger's connection check (CC1) is the last to connect — so the charger only knows the plug is fully in when everything else is already touching.
The full sequence is in clause 6.3. If you design plugs, sockets or test rigs, it is one of the first things to check.
The lock: now a must
At 500 or 800 A, a plug that comes loose is dangerous. The 2023 edition is clear:
- The DC connector shall have a mechanical lock that stops it from coming out during normal charging. The plug has the locking lever; the car socket has the matching notch.
- The plug should also have an electronic lock that holds the lever.
- It should have an emergency release, so the plug can still be removed if the electronic lock fails or loses power.
- Exception: plugs used by automatic charging devices (charging robots) that people don't plug in by hand don't need the lock. The machine does the holding.
Who needs GB/T 20234.3-2023?
- Charger makers — plug design, cable, cooling and locking
- Electric vehicle makers — the vehicle inlet and its installation
- Connector and cable makers — dimensions, ratings, pin sequence
- Foreign carmakers selling in China — the car inlet must match the Chinese plug
- Test laboratories checking chargers and vehicles
What should you do now?
- Check your rating. Pick the right voltage (750, 1,000 or 1,500 V) and current class, natural or active cooling.
- Check the lock. Mechanical lock on every manual DC plug; plan an electronic lock and an emergency release.
- Check the CC2 pin sleeve on vehicle sockets against the new height.
- Verify the pin sequence on samples against clause 6.3.
- Read Part 1 and GB/T 27930 together with Part 3: tests and communication live there.
The drawings, dimensions and tolerances your design team needs are in the full text.
Get the full English PDF of GB/T 20234.3-2023 now — instant download, invoice included.