EV Charger Guide

Electric Vehicle Charger Buyer's Guide

Why Drive an Electric Vehicle?

Choosing to drive a vehicle that does not use gasoline helps to reduce greenhouse gas emissions (GHGs). Burning a gallon of gasoline adds 19.6 pounds (8,887 grams) of carbon dioxide (CO2) to the atmosphere (source: epa.gov). This means that for a vehicle that gets 31 miles per gallon, such as a 2024 Ford Escape, for every hundred miles driven 63.2 pounds of CO2 will be emitted. While CO2 will eventually be absorbed by the oceans, vegetation, and soil, it will be hundreds of years (at least) before the released CO2 will have been fully removed from the atmosphere (source: mit.edu)

With an electric vehicle, the emissions associated with electricity use varies based on how the electricity is generated, but in the United States in 2022 the national average was 0.86 pounds of CO2 per kWh generated (source: eia.gov). An electric vehicle such as a 2025 Chevrolet Equinox will use 31 kWh of electricity to travel 100 miles, which means that 26.7 pounds of CO2 would be emitted given current sources of electricity. This means that the EV will lead to a reduction of 36.5 pounds of CO2 emissions for each hundred miles driven than would have been emitted from a gas-powered vehicle with a 31 mpg rating. Given the number of miles driven in the U.S. each year (3.16 trillion miles in 2023, source: energy.gov), the clmate benefits associated with a shift away from gasoline-powered vehicles will be huge.

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Why Install an EV Charger?

Once you have an electric vehicle, the one of the first things to consider is how to charge the vehicle. One option is simply plugging the vehicle into a common 120 volt outlet, which will add about 3 miles of range per hour of charging. This may be fine for recharging plug-in hybrid vehicles, but it may not be practical for many EV owners. Another option would be to use public charging stations. There were 184,000 public EV charging stations in the United States at the end of 2023 (source: energy.gov), and growth continues to be robust. While public charging stations may be best choice for EV owners in apartments and condominiums, for those with access to a private driveway or garage, the benefits of installing a 240 volt Level 2 EV charger are compelling. 

• Convenience: When an EV owner has a Level 2 EV Charger installed, it means vehicle will be able to charge overnight, every night. The need to use a public charging station will likely be be limited to long trips.
• Environmental Benefits: Having an EV charger ar your house or business may provide the opportunity for charging the EV with a 100% renewable source when rooftop solar is installed or when electricity purchased from the grid is from a renewable source.
• Lower Charging Costs: When available, time of use rates, off-peak rates, and demand response programs provide the opportunity to charge during periods when electric rates are lowest, and/or to be compensated for not charging during peak periods, reducing electricity costs. 
• Increased Property Value: Even if you do not have an electric vehicle, installing an EV charger prior to selling a house can more than pay for itself. Research from the Center for Global Sustainability in the School of Public Policy at the University of Maryland found that close proximity of an EV charger to a home could increase a home's value by 3.3% or more (source: umd.edu).

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General Features

EV chargers for residential use are usually 240 volt Level 2 chargers, which will add about 30 miles of range for each hour of charging.  The need for a 240 volt connection means that most people willl require the services of a licensed electrician to install it, but when selecting a Level 2 charger following are some key features to consider.

• Hardwire or NEMA Plug: There are three common ways to connect the EV Charger to the power source. Some come with a NEMA 6-50 plug, some have a NEMA 14-50 plug, and some are intended to be hardwired. If a NEMA 6-50 outlet (3-wire connection) or 14-50 outlet (4-wire connection) already exists you will want to order a charger with a compatible plug. Otherwise, the benefit of a charger with one of the NEMA plug configurations will allow the EV charger to be more easily replaced or upgraded in the future without the need for an electrician, or if you move you will be able to take the charger with you. The benefit of a hardwire EV Charger is that the initial installation costs may be less since a NEMA 6-50 ot 14-50 outlet will not also need to be installed. NEMA 14-50 outlets are more common, while NEMA 6-50 outlets are likely to be less expensive to install.
• Vehicle Interface: When choosing a Level 2 EV charger, verify that the plug will work with the EV to be charged. Most EVs accept a J1772 style plug from the charger to the vehicle, which is the North American standard for most Level 2 chargers. The exception are Teslas, which use the NACS standard, allowing connections to both Level 2 chargers and Level 3 superchargers. For connecting to chargers with a J1772 plug, Teslas use an adapter that allows that the J1772 plug to connect to the vehicle. 
• Cable Length: EV charging cables are not necessarily all the same length. A longer cable will allow the vehicle to be parked further away from the charging station. Consider this when deciding where the EV charger should be located.
• Amperage: An EV charger supporting a higher amperage setting will allow a vehicle to be charged more quickly, while EV chargers with a lower maximum amperage will usually be less expensive. Note that the effective maximum amperage will, however, be limited by the circuit capacity. National Electric Code dictates that a continuous load's draw (an EV charger is considered a continuous load) should be limited to 80% of the circuit's capacity. If the circuit has a 50 amp breaker, for instance, the maximum output will be 40 amps (which is 80% of 50 amps), regardless of the EV charger's rating.  
• App Capabilities: The manufacturers of EV chargers all offer a smart phone app to allow use of the EV charger to be monitored and controlled. Typical capabilities through the app include the ability to set the current limit, schedule charging, and monitor charging activity, and receive notifications when charging is complete, but there may be differences worth considering.
• ENERGY STAR®: EV chargers that are ENERGY STAR certified use 40% less electricity when in standby mode than conventional EV chargers. Since most EV chargers are in standby mode 85% of the time, selecting a charger that is ENERGY STAR certified will help to reduce wasteful energy use. (source: energystar.gov)

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Differentiators

Following are key dfferentiators between some of the available brands.

• Support for Multiple EVs: For households with more than one electric vehicle, it may be desirable to be able to charge each simultaneously. The usual requirement would be to have a dedicated circuit run to each EV Charger.  Wallbox allows two EV chargers to be attached to the same circuit, with the chargers able to share the available electricty between them.
• Charging Networks: Beyond being able to use the ChargePoint app to control and monitor the EV charger installed at the house, users are also able to use the ChargePoint app to find and utilize ChagePoint's growing public charging network.
• Renewble Systems Integration: For homes with on-site solar power generation, Wallbox offers the ability to select whether to charge only when solar power is being generated, or to allow charging from a mix of renewable and grid-supplied electricity. 

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Summary

Electric vehicles are central to decarbonization initiatives, but the user experience can be further enhanced through the convenience of at-home charging. Selecting an EV charger suitable for the location, the vehicle, and one that it ENERGY STAR® certified will help to maximize the benefits of EV ownership.

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Disclaimer: The content presented on this page was prepared by the individual(s) listed below, and does not necessarily refect the views of the company or companies utilizing this site.

Contributor: Philip Scarbro

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