Because we’ve always lived with gas cars, we have a common knowledge base about them. As we transition to EVs there are some ideas and terms that we will need to become familiar with. I’ll try to introduce you to them without being nerdy.
Driving an EV is simpler than driving a gas car. You don’t start it, you turn it on. It doesn’t make any noise to let you know it’s on. It does have a familiar “gear selector” showing Park, Reverse, Neutral and Drive. When you come to a stop, it is silent. There is no engine, so there is no noise when you accelerate. It is a bit disorienting at first but you quickly get used to it.
It won’t be long before you’ll need to charge it. The charge port has a door, just like a gas filler. You’ll need to figure out how to open it. Inside the door will be your charge port. Depending on what kind of car you have, it can have one of four common connectors.
Electrical terms EV buyers and homeowners will need to understand.
Kilowatt (kW)
That’s not a typo, it’s a science term. A kilowatt is a unit of measure for energy. A regular outlet in your house provides up to 1.5 kilowatts. Appliances like coffeemakers and electric room heaters operate in that range of power.
An electric range, oven, water heater or clothes dryer, uses a higher power outlet called a NEMA 14-50, which provides up to 9.6 kW. In EV terms, that level of power is called “Level 2” and will charge most EVs overnight.
Nerd alert: The term “energy” is universal, it is not limited to describing electricity. You will see kW used to describe the power of an EVs motor.
A 100 kW electric motor = 134 horsepower.
A 100 horsepower motor = 0.75 kW.
Kilowatt Hour (kWh)
Utility companies charge by the kWh on electric bills. The term describes how much electricity has been consumed over a period of hours. If you run a 1 kW appliance for 2 hours, you’ve consumed 2 kWh. According to the U.S. Energy Information Administration, the average home consumes 893 kWh per month.
EV batteries are rated in how many kilowatt hours they store. In this case, kilowatt hours can be compared to gallons of gas. The more of them you have, the farther you can go between charges. When you charge your car, you add kilowatt hours. When you drive, you use them up. Typical EVs have battery packs that store 20-60 kWh. Of course, the more kWh, the more $$.
Amps, Amperes, Amperage, and Safety
Amps are a rating of the strength of an electrical current. It is fair to consider amps the electrical equivalent of air or water pressure. Wires, and cables like extension cords, are rated in amps. Higher amperage wires can withstand more electrical strength.
Drawing too many amps through a wire can cause overheating and is a common cause of electrical fires. Fuses and circuit breakers are rated in amps. If too many amps are being drawn through a wire, the fuse “blows” to protect the circuit, and prevent overheating the wire to prevent a fire. According to the National Fire Protection Agency, over 50,000 electrical home fires resulting in 500 deaths are reported every year.
EV Charging Connectors
NEMA 14-50 at home | 9.6 kW | 2-5 mph range added.
This is the name of the outlet used for electric ranges, clothes dryers and water heaters. It provides 9.6 kW maximum. An electrician can install one in a garage or on a post outdoors using the same hardware as an RV park power pedestal used for a “50 amp shore power hookup”. If your EV charger plugs into a 50 amp outlet, you can carry it with you and charge your EV at an RV park.
J-Plug – aka SAE J-1772 | 7.2 kW max | 20-25 mph range added
J-plugs are common on older EVs, and there are a lot of charging stations that use them. Public J-Plugs are a step up from your regular outlet at home, but are not the fastest chargers around. You’ll often find them where people can plug in for a few hours, like employee, hotel, theater or shopping center parking lots. Sometimes the ones in municipal lots, schools and colleges, are free.
CCS2 “Combo” | Level 2 or 3
CCS2 is the rising international standard connector because they are versatile. They will connect to either a J-plug or a DC Fast charger. In Europe, Tesla has been mandated to use CCS2 instead of their proprietary connector.
EV Charging Stations
Click here to find charging stations
Level 1 at home | 1.5 kW max | 2-5 mph range
Level 1 is done at home using a regular household outlet. At 20-40 mph of range added overnight, this may be enough for many people. You should use the charge cord that came with the car when possible. You can use an extension cord, but choose it carefully. For safety reasons, it should be one cord, as short as possible, rated for 20 amps, and have a wire gauge of 10-12. When shopping for a cord, all of this information is on the package. You should never use a thin brown or black indoor extension cord, or string cords together.
Level 2 at home | 9.6-11 kW max | 25-40 mph range with NEMA 14-50
Many homes have outlets used for electric ranges and clothes dryers. This outlet, called “NEMA 14-50” can be installed in a garage or an outside wall. Most EVs can be fully charged overnight this way. You should use the charger that came with the EV with no extension cord if at all possible. If you must use an extension cord, it should be as short as possible and must be rated for 50 amps. A dedicated charger can be hard wired and provide up to 11 kW. That is the most power you will be able to get at home. It will charge slightly faster then the NEMA 14-50, but the cost may not be worth it for many people, since either will charge your EV overnight. Another disadvantage is that the only thing a dedicated charger can do is charge the EV. The NEMA 14-50 outlet can be used for other purposes.
Level 2 Public | up to 19 kW
Level 2 is available at many free and fee based charging stations. The plugs that connect to your EV are on the cord, and may be a J-plug, or a CCS2 Combo. It can charge at a rate of up to 19 kW, just a little higher than your high powered home outlet. Teslas come with an adapter that will mate and charge on a J-plug.
Level 3 Public Only | 50 – 300 kW | up to 1,000 mph range added
Level 3 is the fastest way to charge and encompasses several options. Not all EVs can benefit from Level 3 chargers. The car must have a CCS2 or CHADeMo connection. If the connector mates, there is no harm in using one. Your EV and the charger will “shake hands” in computerese, and work together.
Tesla “DCFC” (Direct Current Fast Charger) “Superchargers”
The Tesla supercharger network was way ahead of its time. Tesla began installing high power chargers across the country in 2012, long before anybody else. It is the primary reason they are an EV sales leader. There was no standard, so they created their own. As a result, a Tesla charging station plug will mate only to Tesla vehicles. Connectors on other makes of car do not mate.
Today, charging a Tesla on the latest chargers is rivaling the time it takes to fill a gas tank.
Non Electrical concepts and terms.
MPGe
MPGe means Miles Per Gallon Equivalent. It is shown clearly on the window sticker of every new EV. It can be compared to gas mileage. It’s a rating for the efficiency of an EV. It ranges from 90 to 150, with more being better. Explaining what the numbers actually mean is pretty nerdy, so we’ll skip that part.