EV types, plugs, and home charging

graphic of how hybrids vehicles work, showing battery, generator, internal combustion engine, power split device, and electric motor
U.S. Dept. of Energy

No plug and gas-only hybrid

No plug is needed for a hybrid electric car (called a hybrid electric vehicle or HEV = early Prius) because gasoline in the combustion engine recharges the battery. This vehicle is not as good for the environment compared with a car that uses less or no gasoline.


Level 1 charger

Level 1 electric vehicle charger
Photo: Taylor Braun-Jones

A three-prong plug and the special cord that goes from the three-prong plug and hooks into the car are needed to recharge a plug-in-hybrid electric vehicle (PHEV) or a battery electric vehicle (BEV). A plug-in hybrid electric vehicle runs on gasoline (for backup power) and electricity so the slow recharge with a three-prong plug is less of an issue than recharging a BEV that can only run on the battery. The Level 1 charger is 120 volts and between 15-20 amps. This three-prong plug charger takes about 8-12 hours to charge the vehicle battery or up to 24-48 hours if the battery has no energy left.  For Level 1, charging the car for one hour provides about 4-5 miles of driving.  The cost for a Level 1 charger can be extremely low if a 3-prong outlet on a dedicated circuit already exists near the electric vehicle. Also, a Level 1 charging cord comes with every new electric vehicle.

While the Level 1 charger is simpler, one disadvantage is the L1 charger uses about 6% more electricity than the L2 charger.

Five important features are critical when an electrician installs or checks the power to this Level 1 electric outlet, especially if outdoors:

  1. The electric line from the electric circuit breaker panel (typically in the basement) to the three-prong plug outlet should only provide electricity to the car and not to other uses (for example, the refrigerator). If a three-prong plug exists but it serves other appliances, an electrician will need to run a dedicated line from the circuit breaker panel to the outlet that will charge the car.
  2. in-use outlet cover. This has a waterproof door with a space at the bottom for the cord.
    Photo: Stephen Reardon

    To lessen rain getting between the three-prong outlet and the plug if the outlet is outside, it is a good idea to install an in-use outlet cover (pictured). This has a waterproof door with a space at the bottom for the cord.

  3. The charging station should be between 12 and 48 inches from the floor. Lighting, perhaps turned on by a motion sensor, would help with nighttime charging and increase visibility of the cord.
  4. If you leave the portable cord by the charging station, you should have a hook or shelf to lessen the weight of the cord so it does not pull out of the outlet.
  5. The electric cord should ideally be 25 feet in length.

Level 2 charger

An electric clothes dryer outlet and a portable electric car charging cord comprise a Level 2 charger at 240 volts and up to 80 amps. Electric dryer outlets accept either three- or four-prong plugs, so either a three- or four-prong charging cord would be needed.

three prong outlet
Photo: Stephen Reardon

Three-prong outlet

4 prong outlet
Photo: Stephen Reardon

Four-prong outlet

Alternatively, a Level 2 charger could be an all-in-one unit hardwired charging station that an electrician connects directly to the circuit breaker panel. The charger box has a built in cord that runs from the box to the car. Ideally, the cord can coil over the charging station for storage. Some have recommended only having the dryer plug and the portable charger because the all-in-one unit will eventually break, and the entire system will need to be replaced. Others have cautioned about having a portable charger outside.

Level 2 electric vehicle charging cord
Photo: Anne Lusk

The Level 2 charger will take between 4 to 8 hours to charge the battery. For Level 2, if the vehicle is charging for one hour, it can be driven for 15-25 miles. Some Level 2 chargers can be configured to reduce the cost of charging (and environmental impact) by taking advantage of time-of-use or other special electricity rates. Chargers with those capabilities are usually more expensive.

While the Level 2 charger is more complicated and expensive to install, the Level 2 is a more sought after recharging solution for owners of electric cars and prospective home buyers.

Four important features are critical when an electrician installs the Level 2 charging outlet or the all-in-one charging station, especially if outdoors:

  1. For the Level 2 charger, an electrician is needed to install the charging outlet or the all-in-one charging station. Getting several quotes may keep costs down and ensure safety. The best electrician is one who has installed charging stations before. This installation will cost less if the circuit breaker panel happens to be close to where the car will be charged.
  2. circuit breaker
    Photo: Anne Lusk

    A home might have an electric circuit breaker panel that only provides 100 amps. With other appliances in the house, the panel may need to have 200 amps to add a Level 2 charger.  The circuit breaker panel needs two breaker switches for the Level 2 charger.  A look inside the circuit breaker panel will reveal if space for two additional breakers is available. A tandem circuit breaker can handle two circuits and fits in a single breaker space. These factors may increase the cost for installation.

  3. The costs also depend on whether the Level 2 charger is the portable model or “hard wired” all-in-one charger with the cord integrated as part of the charger. The charger should be UL rated for safety.
  4. The Level 2 charger should be between 42 to 48 inches from the floor. Even more so than with Level 1, outside lighting for the area around the Level 2 charger would help with nighttime charging and increase visibility of the cord.

Tesla  

Tesla also has a Level 2 charging system but the plug is different from those for other BEVs. A Tesla owner can charge at any location with Level 2 chargers using a Tesla adapter. If a Tesla is purchased, Tesla will help with details for installing a charger at the Tesla owner’s home.

If the Tesla is sold or a new Tesla purchased, a factory reset should be completed for the car so the Tesla owner’s charge card, through the Tesla app, is not incorrectly billed for recharging. A Tesla black card (like a credit card) can be used to open or lock a Tesla if the owner does not have a key fob or the app on their smart phone is not working.

Post with cap to provide some shade

Installing a Level 1 or 2 home charging station on a house or post

  • If the Level 1 or Level 2 charging station is on the side of the house, it could have a small slanted roof to lessen exposure to rain or snow.
  • Having a motion sensitive light at the meter or nearby would make charging easier late at night.
  • If the Level 1 or Level 2 charger has to be on a post away from the house to be near the car, the wire will have to be underground. Always call DigSafe (or equivalent) to ensure that there are no electrical wires, gas lines, communications, etc. Wiring in a metal conduit under a driveway must be 18 inches deep. If the wiring is under a road or alley, it must be 24 inches deep. A permit may be required. The height of the wooden post for installing the Level 1 3-prong plug should be high enough to be above snow.
  • If on a post, it is ideal to have a cover over the charger and perhaps a box around the charger and the cord. A roof or overhang will lessen the chance that rain could freeze on the charger and the cord, and protect the charger from sun exposure. A cable organizer bracket should exist to coil the cord, so it is off the ground if the charger is not portable but hard wired.
  • A Level 2 charger can be on the outside of the house or on a post. The cost for the charger itself is between $400 and $600, and the costs for the wiring may be between $100 to $1000.
Explore aesthetic designs for home charging stations

Level 3 supercharger or DC fast charger

For Level 3 supercharging or DC fast charging at 480 volts, if the vehicle is plugged in for 30 minutes, it can be driven up to 170 miles, depending on the vehicle. This supercharger is typically on a highway and used not for home charging but for long trips. Level 3 is meant for road trips or for people who are unable to charge at home or at work. Tesla vehicles and current electric cars can be charged with Level 1 (with an adapter) and Level 2 (with the Wall Connector) that is 60 amps. Any electric car made in the last few years supports some type of Level 3 charging.