EV Charging Connector Types: J1772, Type 2, CCS, CHAdeMO, NACS

Connector type is the first thing a driver checks and one of the first things a charging platform gets wrong. A charger listed with the wrong connector in an app sends drivers to a plug they cannot use. This guide covers the connectors in use today, how they divide between AC and DC, regional differences, and how OCPP and OCPI represent them.

AC vs DC: where the charger is

Every EV battery charges on DC. The question is where the AC-to-DC conversion happens. With AC charging, the station supplies grid AC and the car's onboard charger converts it, so power is limited by the onboard charger, commonly in the range of a few kW to around 11 or 22 kW depending on the car and the region's supply. With DC fast charging, the station contains the converter and feeds DC straight to the battery, so power is limited by the station and the battery's acceptance, from tens of kW to several hundred.

In North America, AC charging is described in levels: Level 1 is 120 V household supply, Level 2 is 208 to 240 V. SAE J1772 Level 2 allows up to 80 A, which is 19.2 kW at 240 V, though most installations are well below that. In Europe, AC charging commonly uses three-phase supply; 22 kW at 32 A three-phase is the usual ceiling for public AC points.

The connectors

CCS1 and CCS2

The Combined Charging System adds two DC pins to the regional AC connector, so the same inlet accepts AC and DC. CCS uses power-line communication over the control pilot for DC charging, with DIN SPEC 70121 or ISO 15118. CCS1 and CCS2 are physically different and not interchangeable, but their communication stack is the same family, which is why charger firmware often shares code between them.

CHAdeMO

CHAdeMO was one of the earliest DC fast charging standards and remains the norm in Japan. It uses a separate large connector and communicates over CAN. Outside Japan it is now mostly a legacy port that operators keep for existing vehicles. It is also notable for supporting bidirectional charging, which made it the basis of many early vehicle-to-grid pilots.

NACS and SAE J3400

NACS is the connector Tesla used in North America, which Tesla opened up as the North American Charging Standard in 2022. SAE published it as J3400, first as a Technical Information Report in December 2023, and has since followed up with related documents, including J3400/1 covering adapters between J3400 and J1772/CCS1. Many automakers have announced a move to J3400 inlets in North America, and many CPOs are adding J3400 cables alongside CCS1.

For software, J3400 is mostly a connector-modeling question: electrically and in protocol terms it uses the same kind of power-line communication as CCS for DC. The practical issues are elsewhere: knowing whether a driver arriving with an adapter will work at your charger, and listing connectors accurately for apps.

GB/T and ChaoJi

China uses the GB/T standards, with separate AC and DC connectors and CAN-based DC communication. ChaoJi is a newer DC design developed jointly by the CHAdeMO association and Chinese standards bodies; you will see it as a connector value in protocols even where hardware is rare.

Megawatt charging (MCS)

Heavy trucks need far more power than a car connector can carry. The Megawatt Charging System (MCS) defines a separate, larger connector for that segment. If you run depot or corridor charging for trucks, expect to model MCS ports alongside CCS.

How OCPP represents connectors

OCPP 1.6 has no connector-type field at all: a connector is just a connectorId integer, and connector type lives in your CSMS's asset records. OCPP 2.0.1 introduces the EVSE and Connector model and the device model, where the Connector component has a ConnectorType variable. Values include cCCS1, cCCS2, cG105 (CHAdeMO), cTesla, cType1, cType2 and sType2, where the c prefix means a fixed cable and s a socket. The device model post shows how to read it with GetVariables or a base report.

[2, "a71c", "GetVariables", {
  "getVariableData": [
    {
      "component": { "name": "Connector", "evse": { "id": 1, "connectorId": 1 } },
      "variable": { "name": "ConnectorType" }
    }
  ]
}]

How OCPI represents connectors

OCPI's Connector object has a standard field (for example IEC_62196_T1, IEC_62196_T1_COMBO, IEC_62196_T2, IEC_62196_T2_COMBO, CHADEMO, GBT_DC), a format of SOCKET or CABLE, a power_type (AC_1_PHASE, AC_3_PHASE, DC), and max_voltage, max_amperage and optional max_electric_power. OCPI 2.2.1 predates J3400, so check with each roaming partner how they expect NACS connectors to be represented before you publish them. The Locations module post covers the full structure.

Common data mistakes

• Listing the DC pins as a separate connector on CCS chargers, or listing the AC side of a CCS inlet as available when the station only does DC.
• Reporting nameplate power per connector on shared-power chargers. Many dual-connector DC units split power when both are in use. Apps and regulators care about what a driver actually gets.
• Wrong `format`. A Type 2 socket (driver brings a cable) listed as a tethered cable sends drivers without cables to a charger they cannot use.
• Not updating asset data after a cable swap, for example when a site adds J3400 cables or retires CHAdeMO.

Key takeaways

• AC charging uses the car's onboard charger; DC charging puts the converter in the station.
• North America: J1772 and CCS1 with J3400 growing. Europe: Type 2 and CCS2. Japan: CHAdeMO. China: GB/T.
• OCPP 2.0.1 and OCPI both carry connector type; OCPP 1.6 does not, so your CSMS asset data has to be accurate.

HashTech handles hardware onboarding and asset modeling as part of the charging platforms we build.