From Guest Blogger Sara: Household Electric Car Chargers: What You Need To Know

As you may already know, Portland is a major market for electric vehicles. According to the U.S. Department of Energy, for every 1,000 households in Portland, there are 8.8 EVs. That’s more than any other metropolitan area in the nation. So, if you’re looking to jump on the low-emission bandwagon, we’ve got some helpful information about charging your EV at home.

If having an electric car is going to be as convenient as it is eco-friendly, you’re going to need to charge it at home. Most plug-in electric cars come with a Level 1 charger that you can plug into any electrical outlet, which carries an ordinary current of 110 volts.

A Level 1 charger will charge your EV, from empty to full, in 10 to 20 hours depending on your make and model. If you’re like most people who are used to gassing up in 10 minutes, that might sound like a very long time. If so, a Level 2 charger might be more your speed. It can charge your car in four to eight hours, allowing you to have it charged overnight and ready in the morning.

While you may have an outlet in your garage ready for your Level 1 charger, you might be weary of the wiring. In that case, you’ll want to have an electrician look things over. They will need to make sure the outlet you’ve selected is on a dedicated circuit, serving no other outlets or switches. The electrician should also make sure the electrical panel will have enough capacity to deal with charging your car.

Many electric car drivers want the speed of a Level 2 charger, which will need to be professionally installed. Basic Level 2 chargers have standard safety features and status lights, while improved, “smart” chargers have features like advanced displays, timers, and the ability to communicate with smart phones and meters. You’ll need to have an electrical contractor choose a spot in your garage where the charging cord won’t get in the way. They will assess the location and size of your electrical panel and existing circuits, and make any upgrades that may be necessary to account for the additional load. One of our electricians who specialize in car charger installations can also tell you about the associated tax credits and rebates.

Posted in Electric Vehicles Tagged with: , , ,
7 comments on “From Guest Blogger Sara: Household Electric Car Chargers: What You Need To Know
  1. Frank Eggers says:

    “While you may have an outlet in your garage ready for your Level 1 charger, you might be weary of the wiring.”

    I can well understand that home owners might be weary after putting up with the inconvenience of having electricians working on their houses for several days. Unfortunately, that is something that may have to be endured if one has an older home; it may be the lesser of two evils.

    If, at some future date, it becomes desirable to have a level 2 electric car charger installed in my garage, there will be no reason to become wary. The power panel is in the garage and the service entrance has more than sufficient capacity. So, installing a level 2 charger would be quite easy.

  2. Sara says:

    Thanks for your input Frank. Hopefully someday we’ll all have level 2 chargers in our garages

  3. Patrick says:

    I have been driving EVs since 2007. Rather than talking about recharging, I find it is better to talk about the rate, rather than the time. Unlike a gas car, you are generally not filling an EV up from near empty. Also, I find it important to point out that most of the time an EV will be filling up over night, so it is not really important how long it takes, as long as it is full by the time I need it.

    Level 1 gives you about 5 miles of range per hour. A 3.3kW Level 2 gives you about 14 miles per hour and a 6.6kW Level 2 gives you about 30 miles per hour.

    Also, when using a Level 1 plugged into a home outlet, if you have a 20A outlet (they have a sideways T on the left side), you should not have any trouble.

    • Frank Eggers says:

      It’s true that a 20A circuit would be better than the more common 15A circuit, but it’s an increase of only 1/3.

      240V circuits come in a variety of ratings. Ones for electric stoves are, if I recall, rated at 50A whereas ones for air conditioners have lower ratings. Apparently Level 2 chargers come in different ratings so probably one could make choices depending on the amount of power conveniently available in the garage.

      The cost of installing a high-powered charger could be somewhat unpredictable. When I had my new house built, I learned that if the neighborhood transformer had insufficient capacity to handle my air conditioning load in addition to its other loads that I would have to pay the full cost of a larger neighborhood transformer! That’s what the law is here in Albuquerque NM, but it may be different in other places. Fortunately the transformer had sufficient capacity. Probably my neighbor’s electric resistance heating requires far more power than my air conditioning but because he was connected first, I would have had to pay the full cost of a bigger transformer if it had had insufficient capacity.

      There could be a problem if several people in a neighborhood wanted to have high powered chargers. Intermediate voltage distribution transformers could even be overloaded. However, it is likely that if electric cars become common that it will happen gradually enough to make adjustments less difficult.

      • Patrick says:

        In Oregon, you don’t have to pay for a new transformer. I suggest using a 20A circuit, if one is available, because these generally don’t have as many other loads on them. The Level 1 charger will only use 12A regardless if it is plugged into a 15A or 20A outlet. I have used them in 15A outlets many times.

        • Frank Eggers says:

          Actually the electrical code limits appliances to 12.5A when used on a 15A circuit. Of course if you plug an appliance with a 15A plug into a 20A circuit, the appliance has no way of knowing that it is plugged into a 20A circuit. Presumably if an appliance has the special plug that will fit only 20A receptacles, it will draw more than 12.5A. I don’t off-hand know how much current an appliance with a 20A plug is permitted to draw, but probably someone here does know.

          • Don Francis says:

            Most local codes will limit the load on a circuit to 80% of the circuti rating. A 15 amp circuit should be limited to no more than a 12 amps. For a 20 amp rated circuit, the load should be no more than 16 amps. All the electric vehicles I have seen equipped with the SAE J1772 compliant charging, will draw only 12 amps regardless of the rating of the circuit. Using a 20 amp rate dedicated circuit provides additional safety factor that the circuit will never be loaded to a critical level. My garage has both a level 2 40 amp 240 volt EVSE installed and a dedicated 20 amp 120 volt receptacle for my friends whose EV’s are not J1772 compliant. I have a 2011 Nissan LEAF SL.

Download a free e-copy of Craig’s first book, a #1 best-seller in energy on “Renewable Energy–Facts and Fantasies.”

Want to understand the thorny challenges in technology, economics, and politics that face the clean energy industry? Download the book.