SAE J1772
SAE J1772, also known as a J plug or Type 1 connector after its international standard, IEC 62196 Type 1, is a North American standard for electrical connectors for electric vehicles. It is maintained by SAE International under the formal title "SAE Surface Vehicle Recommended Practice J1772, SAE Electric Vehicle Conductive Charge Coupler".
The SAE maintains the general physical, electrical, communication protocol, and performance requirements for the electric vehicle conductive charge system and coupler. The intent is to define a common electric vehicle conductive charging system architecture including operational requirements and the functional and dimensional requirements for the vehicle inlet and mating connector.
The J1772 5-pin standard supports a wide range of single-phase alternating current charging rates. They range from portable devices that can connect to a household NEMA 5-15 outlet that can deliver 1.44 kW to hardwired equipment that can deliver up to 19.2 kW. These connectors are sometimes informally referred to as chargers, but they are "electric vehicle supply equipment", since they only supply AC power to the vehicle's on-board charger, which then converts it to the direct current needed to recharge the battery.
The Combined Charging System Combo 1 connector builds on the standard, adding two additional pins for DC fast charging up to 350 kW.
History
The main stimulus for the development of SAE J1772 came from the California Air Resources Board. Early electric vehicles like the General Motors EV1 and Toyota RAV4 EV used Magne Charge, an inductive system. CARB rejected the inductive technology in favor of conductive coupling to supply electricity for recharging. In June 2001, CARB adopted the SAE J1772-2001 standard as the charging interface for electric vehicles in California. This early version of the connector was made by Avcon and featured a rectangular connector capable of delivering up to 6.6 kW of electrical power. The California regulations mandated the usage of SAE J1772-2001 beginning with the 2006 model year.CARB later asked for higher current delivery than the 6.6 kW that the 2001 J1772 standard supported. This process led to the proposal of a new round connector design by Yazaki which allowed for an increased power delivery of up to 19.2 kW delivered via single phase 120–240 V AC at up to 80 amps. In 2008, CARB published a new standard that mandated the usage of the new connector beginning with the 2010 model year; this was approved in 2012.
The Yazaki plug that was built to the new SAE J1772 plug standard successfully completed certification at UL. The standard specification was subsequently voted upon by the SAE committee in July 2009. On January 14, 2010, the SAE J1772 REV 2009 was adopted by the SAE Motor Vehicle Council. The companies participating in or supporting the revised 2009 standard include smart, Chrysler, GM, Ford, Toyota, Honda, Nissan, Rivian, and Tesla.
The SAE J1772-2009 connector specification was subsequently added to the international IEC 62196-2 standard with voting on the final specification slated to close in May 2011. The SAE J1772 connector is considered a “Type 1” implementation providing a single phase coupler.
Vehicle equipment
The SAE J1772-2009 was adopted by electric vehicle manufacturers in the Chevrolet Volt and the Nissan Leaf. The connector became standard equipment in the U.S. market due to the availability of charging stations supporting it in the nation's electric vehicle network.The European versions were equipped with a SAE J1772-2009 inlet as well until the automotive industry settled on the IEC Type 2 “Mennekes” connector as the standard inletsince all IEC connectors use the same [|SAE J1772 signaling protocol] the car manufacturers are selling cars with either a SAE J1772-2009 inlet or an IEC Type 2 inlet depending on the regional market. There are also adapters available that can convert J1772-2009 to IEC Type 2 and vice versa. The only difference is that many European versions have an on-board charger that can take advantage of three-phase electric power with higher voltage and current limits even for the same basic electric vehicle model.
Combined Charging System (CCS)
In 2011, SAE developed a J1772/CCS Combo Coupler variant of the J1772-2009 connector. This was to support the Combined Charging System standard for direct current fast charging, which includes the standard 5-pin J1772 connector along with an additional two larger pins to support fast DC charging. Combo 1 accommodates charging at 200–920 volts DC and up to 350 kW. The combination coupler also uses power-line communication technology to communicate between the vehicle, off-board charger, and smart grid. Seven car makers agreed in late 2011 to introduce the Combined Charging System in mid-2012. The first vehicles using the SAE Combo plug were the BMW i3 released in late 2013, and the Chevrolet Spark EV released in 2014.In Europe, the combo coupler is based on the Type 2 AC charging connector maintaining full compatibility 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 introduced models with CCS in the US. With the introduction of the Model 3 in Europe, Tesla added CCS charging cables to V2 Superchargers. European V3 and V4 Tesla Superchargers include only a CCS charging cable.
Properties
Connector
The J1772-2009 connector is designed for single phase alternating current electrical systems with 120 V or 240 V such as those used in North America and Japan. The round diameter connector is keyed and has five pins :| Row | Position | Function | Notes | |
| Top | 1 | L1 | "AC Line 1" | |
| Top | 2 | N | "AC Neutral" for 120V Level 1 charging or "AC Line 2" for 208–240V Level 2 charging | |
| Bottom | 3 | PE | "Protective Earth" aka Ground | |
| Middle | 4 | PP | "Proximity Pilot" aka "plug present", which provides a signal to the vehicle's control system so it can prevent movement while connected to the electric vehicle supply equipment, and signals the latch release button to the vehicle. | |
| Middle | 5 | CP | "Control Pilot" is a communication line used to negotiate charging level between the car and the EVSE, and it can be manipulated by the vehicle to initiate charging and can carry other information. The signal is a 1 kHz square wave at ±12 volts generated by the EVSE to detect the presence of the vehicle, communicate the maximum allowable charging current, and control charging begin/end. |
The connector is designed to withstand 10,000 mating cycles and exposure to the elements. With 1 mating cycle per day, the connector's lifespan should exceed 27 years.
Release mechanism
The SAE J1772 or Type 1 plug is locked into the car with a hook that is manually operated, mostly by pressing a button with the thumb, which interrupts power. This allows anybody to stop charging and even theft of the cable. To prevent this, the European IEC 62196 Type 2 connector has openings on the side for automatic locking and release, operated by the car owner via remote control. If the car locks or releases its plug, the charger follows suit according to the PP signal.In addition, the charge port on many modern cars with a J1772 connector have an extendable pin that blocks the J1772 latch from being raised. By extending this pin, it becomes impossible to raise the release latch. In this way, the vehicle can prevent a plugged-in J1772 connector from being removed. This is essential for the CCS implementation where the connector is not designed to break the heavy DC charging current.
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 released revisions of J1772 also listed a never-implemented AC Level 3, which was considered but never implemented.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 and energy efficiency of, it can use its portable charge cord to charge at AC Level 1 to get up to of range per hour or go off an AC Level 2 charging unit to get up to of range per hour. Using an optional DC fast charging port, this model can also charge at up to 55kW to get up to of range per hour.
Other EVs use an 800 V battery architecture to charge much faster. According to Hyundai, "With a 350 kW DC charger, IONIQ 5 can charge from 10 percent to 80 percent in just 18 minutes. According to WLTP cycle, IONIQ 5 users only need to charge the vehicle for five minutes to get 100 km of range." These vehicles are capable of accepting up to 230kW until about 50% State of charge, allowing these vehicles to recharge much quicker than similar EVs with lower voltage batteries.
Some EVs extend J1772 to allow AC Level 1 charging at greater than 16 amps. This is useful, for example, at RV parks where TT-30 receptacles are common. These allow charging at up to 24 amps. However, this level of 120V charging has not been codified into J1772.
Another extension, supported by the North American Charging System, is Level 2 charging at 277V. Like 208V, 277V is commonly found in North American commercial three-phase circuits.
Safety
The J1772 standard includes several levels of shock protection, ensuring the safety of charging even in wet conditions. Physically, the connection pins are isolated on the interior of the connector when mated, ensuring no physical access to those pins. When not mated, J1772 connectors have no power at the pins; they are not energized until commanded by the vehicle.The proximity detection pin is connected to a switch in the connector release button. Pressing the release button causes the vehicle to stop drawing current. As the connector is removed, the shorter control pilot pin disconnects first, causing the EVSE to drop power to the plug. This also ensures that the power pins do not disconnect under load, causing arcs and shortening their life. The ground pin is longer than the other pins, so it connects first and breaks last.