Developing Infrastructure to Charge Plug-In Electric Vehicles

Photo of charging connector and plug.

The SAE J1772 charge port (right) on a vehicle can be used to accept charge with AC Level 1 or 2 charging equipment. The DC fast charge receptacle (left) uses a different type of connector, in this photo it is a CHAdeMO.

To widely accept the use of plug-in hybrid electric vehicles (PHEVs) and all-electric vehicles (EVs), consumers and fleets need access to charging stations, also known as EVSE (electric vehicle supply equipment). For most drivers, this starts with charging at home or at fleet facilities. Charging stations at workplaces and public destinations may also bolster the market acceptance. Community leaders can find out more about getting ready for plug-in vehicles from Clean Cities PEV vehicle community readiness projects or assess your community's readiness by using the PEV Readiness Scorecard tool.

Charging Equipment

Charging equipment for plug-in electric vehicles (PHEVs or EVs) is classified by the rate at which the batteries are charged. Charging times vary based on how depleted the battery is, how much energy it holds, the type of battery, and the type of EVSE. The charging time can range from 15 minutes to 20 hours or more, depending on these factors.

AC Level 1 Charging

2 to 5 miles of range per
1 hour of charging

J1772 charge port

AC Level 1 EVSE (often referred to simply as Level 1) provides charging through a 120 volt (V) AC plug. Most, if not all, plug-in electric vehicles (PEVs) will come with an AC Level 1 EVSE cordset so no additional charging equipment is required. On one end of the cord is a standard NEMA connector, (for example, a NEMA 5-15, which is a common three-prong household plug) and on the other end is a SAE J1772 standard connector. The SAE J1772 connector plugs into the car’s J1772 charge port and the NEMA connector plugs into a standard NEMA wall outlet.

AC Level 1 is typically used for charging when there is only a 120V outlet available, but can easily provide all of a driver's needs. For example, 8 hours of charging at 120V can replenish about 40 miles of electric range.

AC Level 2 Charging

10 to 20 miles of range per
1 hour of charging

J1772 charge port

AC Level 2 equipment (often referred to simply as Level 2) offers charging through 240V (typical in residential applications) or 208V (typical in commercial applications) electrical service. Most homes have 240V service available, and because AC Level 2 EVSE can charge a typical EV battery overnight, they will commonly be installed at EV owners' homes for home charging or are used for public charging equipment. This charging option can operate at up to 80 amperes and 19.2 kW. However, most residential AC Level 2 EVSE will operate at lower power. Many such units operate at up to 30 amperes, delivering 7.2 kW of power. These units require a dedicated 40 amp circuit.

AC Level 2 equipment uses the same SAE J1772 connector and charge port that Level 1 equipment uses. All commercially available PEVs have the ability to charge using AC Level 1 and AC Level 2 charging equipment. Although Tesla vehicles do not have a J1772 charge port, they do sell an adapter.

DC Fast Charging

50 to 70 miles of range per
20 minutes of charging




Direct-current (DC) fast charging equipment, sometimes called DC Level 2 (typically 208/480V AC three-phase input), enables rapid charging along heavy traffic corridors at installed stations. There are three types of DC fast charging systems, depending on the type of charge port on the vehicle: a J1772 combo, CHAdeMO, or Tesla.

The J1772 combo is used by Chevrolet and BMW and is unique because a driver can use the same charge port when charging with Level 1, 2, or DC Fast equipment. The only difference is that the DC Fast connector has two bottom pins.

The CHAdeMO is the most common of the three connector types and is used by Nissan, Mitsubishi, Toyota, and Fuji.

Tesla vehicles have a unique charge port and connector that works for all their charging options including their fast charging option, called a supercharger.

Future AC Charging Options

An additional standard (SAE J3068) is under development for higher rates of AC charging using three-phase power, which is common at commercial and industrial locations in the United States. Some components of the standard will be adapted from the European three-phase charging standards and specified for North American AC grid voltages and requirements. In the U.S., the common three-phase voltages are typically 208/120 V, 480/277 V. The standard will target power levels between 6kW and 130kW.

Inductive Charging

Inductive charging equipment, which uses an electromagnetic field to transfer electricity to a PEV without a cord, has been recently introduced commercially for installation as an aftermarket add-on. Currently available wireless charging stations operate at power levels comparable to AC Level 2.