SAE J1772, also called a J plug or Type 1 connector, follows the international standard IEC 62196 Type 1. It is a North American standard for electrical connectors used in electric vehicles. SAE International manages this standard, which is officially titled "SAE Surface Vehicle Recommended Practice J1772, SAE Electric Vehicle Conductive Charge Coupler."

SAE sets the rules for the physical design, electrical functions, communication protocols, and performance of the electric vehicle charging system and its connector. The goal is to create a shared charging system design that includes rules for how the system works, as well as the size and function requirements for the vehicle’s charging port and the matching connector.

The J1772 5-pin standard supports various single-phase alternating current (AC) charging speeds. These range from portable devices that connect to a standard household outlet (NEMA 5-15) and provide up to 1.44 kW (12 A @ 120 V) to fixed equipment that can deliver up to 19.2 kW (80 A @ 240 V). These connectors are sometimes called "chargers," but they are officially called "electric vehicle supply equipment" (EVSE) because they only provide AC power to the vehicle’s on-board charger, which converts it to direct current (DC) for the battery.

The Combined Charging System (CCS) Combo 1 connector uses the J1772 standard and adds two extra pins to allow direct current (DC) fast charging up to 350 kW.

History

The main reason for creating the SAE J1772 standard was the California Air Resources Board (CARB). Early electric vehicles, such as the General Motors EV1 and Toyota RAV4 EV, used a system called Magne Charge (SAE J1773), which relied on magnetic fields to transfer energy. CARB decided not to use this inductive system and instead chose a conductive method to supply electricity for recharging. In June 2001, CARB approved the SAE J1772-2001 standard as the charging interface for electric vehicles in California. This first version of the connector was made by Avcon and had a rectangular shape. It could deliver up to 6.6 kilowatts of power. California laws required the use of SAE J1772-2001 starting with the 2006 model year.

Later, CARB requested higher power delivery than the 6.6 kW supported by the 2001 standard. This led to a new design by Yazaki, which used a round connector and allowed up to 19.2 kW of power through single-phase 120–240 V AC at up to 80 amps. In 2008, CARB published a new standard requiring the use of this connector starting with the 2010 model year, which was finalized in 2012.

The Yazaki plug, built to the new SAE J1772 standard, passed certification by UL. The SAE committee approved the updated standard in July 2009. On January 14, 2010, the SAE J1772 REV 2009 was officially adopted by the SAE Motor Vehicle Council. Companies involved in or supporting this standard included smart, Chrysler, GM, Ford, Toyota, Honda, Nissan, Rivian, and Tesla.

The SAE J1772-2009 specification was later included in the international IEC 62196-2 standard, which focuses on dimensional compatibility and interchangeability for AC charging accessories. Final approval for this standard was expected by May 2011. The SAE J1772 connector is classified as a “Type 1” implementation, using a single-phase coupler.

The SAE J1772-2009 standard was used in vehicles like the Chevrolet Volt and Nissan Leaf. It became the standard in the U.S. due to the availability of charging stations supporting it, aided by programs like ChargePoint America, which received funding from the American Recovery and Reinvestment Act.

In Europe, vehicles initially used the SAE J1772-2009 inlet until the industry adopted the IEC Type 2 “Mennekes” connector as the standard. However, all IEC connectors use the same SAE J1772 signaling protocol, so cars sold in different regions may have either a SAE J1772-2009 inlet or an IEC Type 2 inlet. Adapters are available to convert between the two. European models often include an on-board charger capable of using three-phase power with higher voltage and current limits, even for the same vehicle model, such as the Chevrolet Volt/Opel Ampera.

In 2011, SAE developed a J1772/CCS Combo Coupler variant of the J1772-2009 connector. This was designed to support the Combined Charging System (CCS) standard for direct current (DC) fast charging. The combo coupler includes the standard 5-pin J1772 connector and two additional larger pins for DC charging. Combo 1 supports charging at 200–920 volts DC and up to 350 kilowatts. The coupler also uses power-line communication technology to connect the vehicle, off-board charger, and smart grid. In late 2011, seven carmakers (Audi, BMW, Daimler, Ford, General Motors, Hyundai, Porsche, Volvo, and Volkswagen) agreed to introduce the CCS standard by mid-2012. The first vehicles using the SAE Combo plug were the BMW i3 (late 2013) and the Chevrolet Spark EV (2014).

In Europe, the combo coupler is based on the Type 2 (VDE) AC charging connector (Combo 2), which is fully compatible with the SAE specification for DC charging and the HomePlug Green PHY PLC protocol. In 2019, Tesla introduced the Model 3 with a CCS Combo 2 plug in Europe but has not used CCS in the U.S. With the Model 3’s release, Tesla added CCS charging cables to V2 Superchargers, supporting both CCS Combo 2 and Tesla DC Type 2. European V3 and V4 Tesla Superchargers now only include CCS charging cables.

Properties

The J1772-2009 connector is used for single-phase alternating current (AC) electrical systems that operate at 120 V or 240 V, such as those found in North America and Japan. This round connector has a diameter of 43 millimeters (1.7 inches) and is keyed with five pins visible from the outside of the plug.

The connector is built to last through 10,000 mating cycles, which means it can be plugged in and unplugged 10,000 times. If used once each day, the connector could last over 27 years.

Examples of the connector include:
– A black release button on an SAE J1772 plug in a car model.
– SAE J1772 plugs used at a VinFast charging station, operated by pressing a thumb.
– An adaptor cable from Nissan with a Type 1 plug for the car and a Type 2 plug for a European charger.
– An IEC 62196 Type 2 connector with side openings for automatic release.

The SAE J1772 or Type 1 plug is locked into the car using a hook that is manually operated, usually by pressing a button with the thumb. This action stops the power flow, allowing anyone to stop charging or even remove the cable. To prevent this, the European IEC 62196 Type 2 connector has side openings for automatic locking and release, controlled remotely by the car owner. When the car locks or releases the plug, the charger follows the command based on the PP signal.

Many modern cars with J1772 connectors have an extendable pin that prevents the latch from being raised. When extended, this pin stops the release latch from moving, keeping the connector securely attached. This feature is important for CCS (Combined Charging System) implementation, where the connector is not designed to handle the high direct current (DC) used during fast charging.

The SAE J1772-2017 standard defines four levels of charging: AC Level 1, AC Level 2, DC Level 1, and DC Level 2. Earlier versions of the standard included a never-implemented AC Level 3.

For example, the 2020 Chevrolet Bolt has a 66-kWh lithium-ion battery and a 7.2-kW onboard charging module. With an EPA range of 259 miles (417 km) and energy efficiency of 118 mpg-e (29 kW·h/100 mi; 17.7 kW·h/100 km), it can charge using AC Level 1 (120 V, 12 A) to gain up to 4 miles (6.4 km) of range per hour or AC Level 2 (240 V, 32 A) to gain up to 25 miles (40 km) of range per hour. Using an optional DC fast charging (DCFC) port, this model can charge at up to 55 kW to gain up to 180 miles (290 km) of range per hour.

Some electric vehicles (EVs) use an 800 V battery system (like those on Hyundai’s E-GMP platform) to charge faster. According to Hyundai, the IONIQ 5 can charge from 10% to 80% in 18 minutes using a 350 kW DC charger. According to the WLTP cycle, users can charge the vehicle for 5 minutes to gain 100 km of range. These vehicles can accept up to 230 kW of power until about 50% battery charge, allowing them to recharge faster than EVs with lower voltage batteries.

Some EVs extend J1772 to allow AC Level 1 (120 V) charging at more than 16 amps. This is useful at RV parks with TT-30 ("Travel Trailer") receptacles (120 V, 30 A), which allow charging at up to 24 amps. However, this level of 120 V charging is not officially included in the J1772 standard.

Another extension, supported by the North American Charging System, includes Level 2 charging at 277 V. Like 208 V, 277 V is commonly used in North American commercial three-phase circuits.

The J1772 standard includes safety features to prevent electrical shocks, even in wet conditions. When the connector is plugged in, the pins inside are isolated, making them inaccessible. When not plugged in, the pins are not energized until the vehicle commands power.

A proximity detection pin is connected to a switch in the release button. Pressing the button stops the vehicle from drawing current. As the connector is removed, the shorter control pilot pin disconnects first, causing the EVSE (Electric Vehicle Supply Equipment) to stop power to the plug. This prevents power pins from disconnecting under load, which could cause sparks or damage. The ground pin is longer than the others, so it connects first and disconnects last.

Signaling

The signaling protocol is used for the following charging process:

• The charging station tells the vehicle that AC power is available.
• The vehicle detects the plug using a proximity circuit (this helps prevent the vehicle from moving while connected) and can sense when the plug is ready to be removed.
• The Control Pilot (CP) functions begin. The charging station detects the Plug-in Electric Vehicle (PEV), tells the PEV it is ready to supply power, determines the PEV’s ventilation needs, and shares its current capacity with the PEV.
• The PEV commands the flow of energy.
• The PEV and charging station continuously check that the safety ground connection remains intact.
• Charging continues based on the PEV’s instructions.
• Charging can stop if the plug is disconnected from the vehicle.

The technical details of this protocol were first described in the 2001 version of SAE J1772. Later, the IEC 61851-1 and IEC TS 62763:2013 standards also included these specifications. The charging station sends 12 volts through the Control Pilot (CP) and the Proximity Pilot (PP), measuring the voltage differences. This protocol does not require complex circuits, making SAE J1772 reliable and functional in temperatures from −40 °C to +85 °C.

Control Pilot (Mode): The charging station sends a 1 kHz square wave through the CP. This signal connects to the vehicle’s protective earth via a resistor and a diode (voltage range: ±12.0±0.4 V). If the CP–PE (Protective Earth) circuit is open, the live wires of public charging stations are inactive, even though the standard allows a charging current as in Mode 1 (maximum 16 A). If the circuit is closed, the charging station checks if the protective earth works properly. The vehicle can request specific charging functions by changing the resistance between the CP and PE pins:
– 2.7 kΩ signals a Mode 3 compatible vehicle (no charging needed).
– 880 Ω means the vehicle is ready to charge.
– 240 Ω requests ventilation-based charging, where the charging station supplies power only if the area is ventilated (e.g., outdoors).

Control Pilot Line Circuitry Examples: In SAE J1772:2001, the CP–PE current loop is permanently connected on the vehicle side via a 2.74 kΩ resistor. When a cable is connected to the charging station, the voltage drops from +12 V to +9 V, activating the wave generator. The vehicle can start charging by adding a 1.3 kΩ resistor (voltage drops to +6 V) or a 270 Ω resistor for ventilation (voltage drops to +3 V). The charging station checks the voltage on the CP–PE loop to respond. The diode allows only positive voltage to pass. Negative voltage on the CP–PE loop is blocked by a diode in the vehicle, and significant current during negative periods stops the system, as it may signal a dangerous error (e.g., touching pins).

IEC62196-2 Male Plugs: The Control Pilot pin is shorter to prevent untethered cables from being used as extension leads. This avoids connecting cables with lower current capacity to those rated for higher currents.

Control Pilot (Current Limit): The charging station uses the wave signal to indicate the maximum current available through pulse-width modulation (PWM). For example:
– 16% PWM = 10 A maximum.
– 25% PWM = 16 A maximum.
– 50% PWM = 32 A maximum.
– 90% PWM = fast charge option.

The PWM duty cycle of the 1 kHz CP signal shows the maximum allowed current from the power source. According to SAE, this includes the socket outlet, cable, and vehicle inlet. In the U.S., ampacity (current capacity) is divided into continuous and short-term use. The SAE formula calculates ampacity based on the 1 ms cycle of the 1 kHz signal. For example:
– Up to 850 μs: 0.6 A per 10 μs (maximum 6 A at 100 μs).
– Above 850 μs: Subtract 640 μs from the total time, multiply the difference by 2.5. Example: ((960 μs − 640 μs)/10 μs) × 2.5 A = 80 A.

Proximity Pin (PP): The PP pin (also called "plug present") connects to a switch (S3) linked to the connector’s latch release. During charging, the EVSE (charging station) connects the PP–PE loop via S3 and a 150 Ω resistor (R6). When the latch is released, a 330 Ω resistor (R7) is added on the EVSE side, changing the voltage to allow the vehicle to shut off power before disconnecting. However, some low-power adapters lack this feature.

IEC 62196 Standards: The Proximity Pin also indicates the cable’s maximum current capacity, important for non-tethered EVSEs. A resistor (Rc) between the PP and PE in the detachable cable assembly determines the cable’s capability. If the current exceeds the cable’s limit, the vehicle stops the flow of electricity.

Future Updates: An updated standard (due in 2012) proposed using power line communication (specifically IEEE 1901) between the vehicle, charging station, and smart grid, without needing an extra pin. SAE and the IEEE Standards Association are sharing draft standards for smart grid and vehicle electrification.

P1901 Communication: This method works with other 802.x standards via IEEE 1905, enabling IP-based communication with the vehicle, meter, or building. It includes wireless communication. In some systems, communication between the off-board DC EVSE and PEV happens through the pilot wire of the SAE J1772 connector using HomePlug Green PHY power line communication (PLC).

Competing standards

A competing design called the Mennekes connector, started by RWE and Daimler, became an official standard in 2011 as Type 2 in IEC 62196. It is now the European Union's standard for single- and three-phase charging connectors. This connector uses the same rules for the pilot pin as the J-Plug from J1772. The IEC standard allows up to 63 A and 43.6 kW of power. In 2018, the SAE J3068 committee released an improved version of the EU connector for the North American industrial market, allowing up to 160 A and 166 kW on three-phase power.

The same IEC 62196-2 standard also included a Type 3 connector from Scame Global, which works for single- and three-phase charging and has shutters. After a 2016 IEC approval for a small change to the Mennekes connector that optionally added shutters, Type 3 was no longer used.

Tokyo Electric Power Company created a standard for high-voltage DC fast charging using the JARI DC connector. It formed the CHAdeMO (charge de move) group with Japanese carmakers Mitsubishi, Nissan, and Subaru to promote this system.