By Mike Gardiner, Product Manager, ITT Interconnect Solutions -- In today’s automotive marketplace, consumers are demanding economical, fuel-efficient vehicles that still provide the safety standards, sleek engineering and hands-free controls that have become standard features in luxury models. As the pendulum has swung away from gas-guzzling status symbols of ‘bigger is better’ vehicles, today’s marketplace has ushered in era of alternative energy and electrically-powered vehicles. Manufacturers are designing new vehicle models with energy efficiency in mind to meet this growing public demand.
Consumer enthusiasm for alternative vehicle technologies, including the development of hybrid and electric vehicles, has rapidly increased in recent years due to environmental concerns and the rising cost of oil/gasoline. The mass acceptance of electric vehicles has undoubtedly been delayed due to the lack of an established charging infrastructure to support the vehicles. Another source of skepticism by the general public is the perceived inconvenience and inefficiency of the electric vehicle’s charging system. The lithium-ion battery that powers the electric motor requires a relatively long time to recharge and the battery life — the distance a driver can travel between charges — is much shorter than desired by consumers.
A recent advancement in connector technology has enabled design engineers to address consumers’ concerns about the electric vehicle’s charging time requirements, thus resolving an uncertainty that has prevented the electric vehicle industry from accelerating its growth, and thus fostering a wider acceptance of environmentally friendly vehicles.
SAE J1772 Charging Standard
The Society of Automotive Engineers (SAE) established the SAE J1772 Electric Vehicle and Plug In Hybrid Electric Vehicle Conducive Charge Coupler specification to cover the electrical and physical performance requirements and communication procedures for the charge systems of electric vehicles. This charging standard was adopted in January 2010 by both the United States and Japan for Level I and Level II electric vehicle charging, and has been accepted by many of the leading electric vehicle manufacturers including GM, Ford, Honda, Nissan and Toyota.
• Level I: AC energy to the vehicle’s on-board charger; from the most common U.S. grounded household receptacle, commonly referred to as a 15A, 110-120 volt outlet.
• Level II: AC energy to the vehicle’s on-board charger; 208-240 volt, single phase. The maximum current specified is 32 amps (continuous) with a branch circuit breaker rated at 40 amps. Maximum continuous input power is specified as 7.68 kW (240V x 32A).
Safety
The SAE J1772 charging specification states that electric vehicle charging solutions must pass the stringent UL 2251 certification, thus requiring an extremely robust coupler. In addition, the electric vehicle charging solution must deliver high-amperage charging for fast, easy and safe charging of any electric vehicle in order to meet customer requirements. 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 voltage at the pins, and charging power does not flow until commanded by the vehicle.
The pins are designed to provide first-make, last-break functionality; meaning that when the plug is in the charging port of the vehicle and charging, and it is removed, the control pilot and proximity detection pins will “break” contact first, thus ensuring that the power pin relay in the charging station will be immediately shut off and no current will flow.
Related Story: NFPA, SAE to hold 2nd annual Electric Vehicle Safety Standards Summit
Electric Vehicle Recharging Solution
Manufacturers addressing the need for a high-amperage solution have reduced the Level II charge time by 50%, as illustrated by ITT Interconnect Solutions’ EVC Series connectors. This advanced charging solution features highly efficient power contacts to provide flexible functionality, with minimal modifications, across a power curve ranging from a low of 15 amps/120 volts to a high of 75 amps/240 volts. Five contacts (two power, one ground, and two signal) make up the J1772 inlet, which features a touch-proof seal on the power and ground contacts. This flexible interconnect system is designed to exceed the electrical and mechanical UL specifications, as well as the SAE 1772 specifications across the power curve.
Rugged and Reliable
The ITT interconnect solution incorporates robust and proven technology with the high efficiency power (HEP) contact system. Temperature stresses are common in automotive applications, requiring interconnects to withstand extreme temperatures. Moisture drain holes are strategically place to prevent latch freezing, thus making the connection functional for outdoor use in extreme environments. The locking feature prevents unauthorized use of the charging system. All plastic-based materials are F1-rated per UL 746 C and are resistant to engine oils and UV rays. The IP44-sealed charging solution is rated for 10,000 plus cycles.
Interconnection Customization
In order to ensure the versatility for powering electric vehicles, the inlet has a rear accessory thread to accept a cable management backshell system that connects to the battery, reducing the required space by 25%. The inlet comes completely wired (with or without a backshell) and custom lengths are available. Backshells can be provided in right angle or straight configurations. An additional sealing cover and panel sealing gasket can be provided as an option for the inlet connector.
Conclusion
Manufacturers are continuously developing new connector designs and technologies to keep pace with these new automotive demands. The recent changes in consumer trends have steered automotive manufacturers away from producing large SUVs and have increased production of smaller, compact, more fuel-efficient vehicles powered by electric or hybrid engines. This shift to hybrid and electric vehicles required the industry to develop the J1772 vehicle charging standard to ensure infrastructure compatibility. Vehicle manufacturers have quickly adopted the J1772 standard, and connector manufacturers have in turn developed customized, high-amperage interconnect systems for recharging vehicles that meet both industry safety specifications and customer ergonomic and performance requirements.
Mike Gardiner is a product manager at ITT Interconnect Solutions, and has more than 30 years of experience in the connector industry. Mike received his B.S. degree from Saint Louis University. Mike can be reached at mike.gardiner@itt.com.
