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SAE J1772 EV Charger Guide

The electric vehicle (EV) market is experiencing exponential growth, with more drivers switching to cleaner and more sustainable transportation options. As EV adoption rises, understanding charging infrastructure becomes increasingly crucial.

At the forefront of EV charging standards in North America is the SAE J1772 connector. While alternative connectors like Tesla, CHAdeMO, and CCS exist, the J1772 standard remains dominant, offering compatibility across various vehicles.

SAE J1772 Connector

The SAE J1772 connector features a distinct physical design and pin configuration, facilitating safe and efficient charging. Contrary to common misconceptions, J1772 chargers can deliver impressive charging speeds at residential and public charging stations.

The SAE J1772 connector, or the J plug or Type 1 connector, is a standard for electric vehicle connectors in North America, supporting AC Level 1 and AC Level 2 charging.

Level 1 chargers are slower, typically plugged into standard household outlets, providing 1.3 kW to 2.4 kW of power and taking up to 24 hours for a full charge. They come with electric vehicles and offer up to 140 miles of range for 20 hours of charging. Level 1 chargers are easily accessible in residential areas and incur no additional costs.

Level 2 chargers, on the other hand, offer faster charging rates ranging from 3 kW to 19 kW, providing 18-28 miles of range per hour and fully charging a battery in 8 hours or less, charging 3 to 7 times faster than Level 1 chargers. These chargers are often found in public charging stations but can also be installed in homes for quicker charging.

FeatureLevel 1 ChargerLevel 2 Charger
Voltage120 VAC208-240 VAC
Max Current16 A (1.9 kW)80 A (19.2 kW)
Power OutputSlowFaster
Typical UseHomePublic stations, home (optional)
Charging Time (for 250-mile range)Up to 24 hours8-10 hours
*Cost (charger)Included with EVSeparate purchase

What Does a J1772 Connector Look Like?

The J1772 connector, or the J-Plug or Type 1 connector, has a circular shape with a diameter of approximately 60 mm (2.36 inches) and five pins.

llustration depicting an SAE J1772 plug and SAE J1772 connector side by side

The housing is thermoplastic, while the pins are copper alloy with silver plating. It has a voltage rating of 120V – 250V AC, a current rating of up to 80 amps, and a power rating of up to 19.2 kW. The connector operates within a temperature range of -30 °C to +50°C (- 22°F to +122°F) and can endure up to 10,000 mating cycles. It includes a manual locking mechanism with a thumb release button for safety.

What Is the Purpose of the J1772 Connector Pins?

SAE J1772 Connector charger features five pins: 3 large power pins (L1, Neutral, PE) and two smaller signal pins (PP, CP). The purpose of the J1772 connector pins is to facilitate safe and efficient AC charging for electric vehicles. Here’s a breakdown of their functions:

Illustration displaying the arrangement of SAE J1772 connector pins, including L1, Neutral, PE, PP, and CP, used in electric vehicle charging

Large J1772 Connector Power Pins:

  • L1 (AC Line 1): With a diameter of 9.5mm, it delivers AC power from the charging station to the vehicle.
  • Neutral (N): Also 9.5mm in diameter, it provides a return path for the AC.
  • PE (Protective Earth/Ground): An 8.0mm diameter ensures electrical safety by grounding the connection and preventing shock hazards.

Small J1772 Connector Signal Pins:

  • PP (Proximity Pilot): 3.0mm in diameter, it detects the presence of the connector and enables communication between the EV and the charging station.
  • CP (Control Pilot): Also 3.0mm in diameter, it facilitates communication between the EV and the charging station to manage charging parameters like current and voltage.

The Main Challenges Facing SAE J1772 Charger Adoption.

Outlined below are some of the challenges facing SAE J1772 charger adoption today:

Incompatibility of Devices

While the widespread adoption of the J1772 standard is undeniable, the presence of the Tesla Supercharger network presents a significant obstacle. Tesla’s exclusive charging infrastructure, incompatible with J1772, creates interoperability challenges for non-Tesla electric vehicles. Despite Tesla’s plans to open certain segments of its network to other EVs via CCS chargers, concerns persist regarding network fragmentation and the seamless integration of alternative charging systems.

Lectron Tesla to J1772 Adapter connected to a Tesla Charger
To address these challenges, EV owners can use the Tesla to J1772 Adapter such as the Lectron Tesla to J1772 Adapter, which offers exceptional performance, delivering up to 40 amps of current and 250 volts of voltage. In simple terms, it significantly reduces charging time, offering a speed three times faster than other Level 2 chargers available in the market. Additionally, the J1772 Adapter supports charging speeds of up to 19.2 kW, ensuring efficient and rapid charging for various electric vehicles.

International Compatibility

J1772’s incompatibility with European (Type 2) and Asian (GB/T) standards complicates international travel for EV owners. Adapters or specialized chargers are necessary for cross-border journeys, adding complexity and inconvenience. Efforts to harmonize charging standards globally could alleviate this challenge and promote smoother EV adoption worldwide.

Limited Implementation of Safety Features

Some J1772 chargers lack essential safety features, such as diode checks and the “Vent Required” state, which monitor grounding integrity and detect overheating in EVs. This deficiency compromises safety during charging sessions, potentially exposing users to electrical hazards. Rigorous enforcement of safety regulations and standards is imperative to ensure uniform compliance and bolster consumer confidence in J1772 infrastructure.

Quality and Reliability Issues

Substandard J1772 chargers pose reliability and safety risks, including malfunctions and overheating. Quality assurance measures, including stringent testing and robust quality control protocols, are essential to weed out inferior products and uphold the integrity of the charging ecosystem.

Overheating Issues

J1772 chargers overheating, even below their rated current, underscores concerns regarding thermal management and component quality. Addressing these issues necessitates enhanced design standards, improved materials, and rigorous performance testing to mitigate the risk of overheating-related incidents.

Deployment Cost

The high cost of installing J1772 charging infrastructure presents a barrier to widespread adoption, particularly compared to more superficial Level 1 charging solutions or proprietary networks. Lowering installation costs through technological innovation, streamlined permitting processes, and targeted incentives could facilitate the expansion of J1772 charging networks and make EV ownership more accessible.

Cost of Ownership

The upfront cost of J1772 chargers may deter individuals and businesses from investing in home or public charging solutions. Lowering the barrier to entry through subsidies, tax incentives, and innovative financing mechanisms could incentivize greater adoption of J1772-compatible charging infrastructure, driving the proliferation of EVs and supporting sustainable transportation initiatives.

Bypassing Regulations

The proliferation of devices that circumvent J1772 and National Electrical Code (NEC) regulations poses significant safety risks and undermines the integrity of the standard. Robust enforcement mechanisms, including stringent certification processes and penalties for non-compliance, are necessary to deter the use of non-compliant equipment and safeguard consumers against potential hazards.

Integration with smart grids and renewable energy sources:

Future iterations of J1772 infrastructure may incorporate advanced features to facilitate seamless integration with smart grids and renewable energy sources. Bidirectional charging capabilities and dynamic pricing mechanisms could enable EVs to serve as grid resources, enhancing grid stability and promoting renewable energy utilization.


In conclusion, the SAE J1772 standard plays a pivotal role in shaping the future of EV charging. Its compatibility, efficiency, and safety features make it a preferred choice for EV owners. As we look ahead to the evolving landscape of electric transportation, embracing J1772 chargers is a step towards a sustainable future. By empowering readers with knowledge and resources, we pave the way for widespread adoption and positive environmental impact.

James Ndungu

About the Author: James Ndungu

James Ndungu, founder and editor-in-chief of Electric Vehicle Geek, brings over five years of hands-on experience in Electric Vehicle Supply Equipment (EVSE) selection, permitting, and installation. He specializes in assisting businesses and homeowners in the United States with a seamless transition to electric vehicles.

As a certified EV charger installer and holder of advanced certifications, including the EVITP (Electric Vehicle Infrastructure Training Program), Diploma in Electric Vehicle Technology, and Diploma in Engineering Fundamentals of Electric Vehicles, I provide expert guidance and in-depth reviews on the latest EV charging equipment.

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