Login
Join Us
Guest Posts
Your Position: Home - Energy - Plug-in Electric Vehicle Charging: The Basics

Plug-in Electric Vehicle Charging: The Basics

Author:

Apr. 09, 2024
Energy

Charging your all-electric vehicle (EV) or plug-in hybrid electric vehicle (PHEV)–together known as plug-in electric vehicles (PEVs)–is similar to charging other electronics. One end of an electrical cord is plugged into your car, and the other end is plugged into a power source or charging equipment.

There are three categories of charging equipment based on how quickly each can recharge a car’s battery. Charging times for PEVs are also affected by:

  • How much the battery is depleted
  • How much energy the battery can store
  • The type of battery
  • Temperature

Charger Fast Facts

Charging Options

Level 1 (120 Volt)
 

Level 2 (240 Volt)
 

Direct-Current (DC) Fast Charging
 

What does the charge port on the vehicle look like?  

How fast do they charge?

About 5 miles per 1 hour of charging*

About 25 miles per 1 hour of charging*

~100 – 300+ miles per 30 minutes of charging†

Where can I find them?

  • In your house/garage
  • Possibly at your apartment/condo and workplace
  • May not need to install anything; some automakers provide charger cords with vehicle purchase
  • In your house/garage (You will need additional equipment)
  • Possibly at your apartment/condo and workplace
  • At public charging stations
  • At public charging stations
  • In many cities and along highway routes across the country (see locations)

EV charger images are courtesy of Con Edison.

Level 1 uses the same outlet you use for your cell phone and toaster. Worth noting:

  • You can plug your car directly into the 120 Volt outlet using the charge cable (technically called the Electric Vehicle Supply Equipment or EVSE) that often comes with the vehicle.
  • Many people with commutes less than 40 miles a day find this sufficient to charge their PEV overnight and meet their daily driving needs.‡

Level 2 uses the same 240 Volt outlet you might use in your home for an electric oven or clothes dryer. Worth noting:

  • It allows for faster home charging and can replenish hundreds of miles of range to your vehicle overnight, ensuring a full battery under most circumstances.
  • If you do not already have a 240 Volt outlet in an ideal location for charging your vehicle, a qualified electrician can help you install a new outlet and a Level 2 charger. They can determine if your home has sufficient capacity or needs an upgraded electrical panel and will ensure work is done properly.

Direct-Current or DC fast chargers are the fastest option for charging PEVs and are found primarily along highways and in cities to enable long-distance trips and quick refueling when it’s needed.

They work by supplying high levels of electricity more directly to your vehicle’s battery and bypassing the equipment in your vehicle that normally converts alternating current (AC) to direct current (DC). Worth noting:

  • Depending on your vehicle and the speed of the DC fast charger, many PEVs can regain hundreds of miles of range in as little as 20-30 minutes. However, if you have access to charging at home or at work using level 1 and 2 chargers, and have more time to charge, they will usually be cheaper than DC fast chargers.
  • The rate of DC fast charging is higher as the vehicle’s battery is closer to empty and slows down as it gets closer to full. It will generally save you time to only DC fast charge your PEV to around 80% of its battery capacity, and then continue on the road to the next charging station. Unless you need the full range of your battery to reach a destination, DC fast charging beyond 80% tends to be significantly slower and it can sometimes double your time spent charging to reach 100%.

Visit the Department of Energy (DOE) website to learn more about charging equipment.

Interested in seeing how many chargers may be needed in your area? Use DOE’s EV Pro Lite Tool to get an estimate on charging needs in your state or metropolitan area as PEV adoption grows.

Visit EV Charging: The Details for answers to frequently asked questions.

*Power levels vary among charging equipment; L1 estimate of recharging time assumes 1.9 kW, L2 assumes 6.6 kW.

†Charging time may be shorter depending on station power. More DC fast charging stations that charge cars quickly are being installed around the country.

‡PEVs should ideally charge on a dedicated circuit, or one without another electrical load. Consult with your electrician and the EVSE manual for detailed specifications.

EV chargers currently come in three different models: Level 1, Level 2, and Level 3. Level 3 is also commonly known as Direct Current Fast Charging (DCFC). In Level 1 & 2. the EV is connected to AC power, 120V or 240V, and a battery charger in the EV converts the AC power to the DC needed to charge the battery and controls the charging process. In DCFC the DCFC converts the AC power to DC and the DC power is sent directly to the EV battery bypassing the onboard battery charger. This allows the DCFC to charge the EV battery directly. Level 1 & 2 charging is generally limited by the AC power available and the size of the onboard battery charger installed in the EV. DCFC is limited by the rating of the DCFC equipment and the amount of power available from the utility or other primary power sources. The charge rate, range of the EV, and the amount of time that the EV is available to recharge, known as the dwell time, work together to determine the best type of EV charging system needed for the application.

Level 1

This charge level is the simplest level of EV charging and consists of plugging the EV into a standard 120V AC receptacle using a unique electrical cord with the appropriate plugs in each end. The built-in battery charger in the EV then charges the battery. This type of charging is generally limited by the amount of power that can be supplied by the receptacle usually, 12-16A or less (1.44-1.92kW) which based on an EV with a 3 MPkWh rating will add up to 5.8 miles for each hour of charging. If we charge for 10 hours overnight, it would only add up to 58 miles to the battery. Level 1 charging is useful for only limited range EVs when daily miles driven are low, or when several days of dwell time are available between EV usage.

Level 1 chargers are inexpensive, readily available, and can be carried with the EV.

Level 2

Level 2 chargers allow the EV to be connected to a 240V receptacle, like that used for an electric range or clothes dryer. Level 2 chargers are currently available up to around 20kW and continuing our example would add 60 miles for each hour of charging at 20kW. Many Level 2 chargers are in the 7kW to 10kW range. Enough to fully recharge most EVs overnight. A long-range car or a delivery van might have a battery capacity of 100kWh and could be recharged over a little more than 10 hours by a Level 2 10kW charger taking system losses into account.

Level 2 chargers are readily available and moderately priced. Higher capacity Level 2 chargers are fixed in place, but lower capacity portable ones are available. Finding a 240V receptacle to plug into can be much more challenging than a Level 1 120V receptacle though.

Level 3 or DCFC

DCFC charging uses DC to charge the EV battery without needing to go through the onboard AC battery charger. This charging level allows for a much higher capacity battery charging system. DCFC chargers, due to the cost and need for 480V electrical service, are usually limited to commercial use, either in commercial fast charging stations or in fleet operations. A 100kW DCFC can recharge an EV with a 100kWh battery in about an hour. At his rate, a 3MPkWh EV will gain 300 miles for each hour of charging.

DCFC chargers are significantly more expensive than Level 1 or 2 chargers and require 480V 3 phase power. This limits them mostly to commercial EV charger installations.

Other Limits on the Speed of EV Charging

There is a limit on the amount of power an EV battery can accept during a charge known as the acceptance rate. This limits the speed that DCFC can charge the EV battery. For instance, if the EV has a 50kW acceptance rate and a 100kW DCFC is connected, the EV will only charge at 50kW.

Plug-in Electric Vehicle Charging: The Basics

Electric Vehicle Charging Systems

Comments

* 0 of 2000 characters used

All Comments (0)
Get in Touch