EV Charging Station Circuit | EVSE Charger Outlet

EVSE Dedicated Circuit

There’s some debate about whether or not you should use a contractor referred by your dealership. The general view is that any qualified electrician can handle the installation, and that you’ll avoid premiums charged by so-called EV installation specialists. The key is if you can absolutely identify a skilled electrician—because a bad electrician can mess up the job.

EV owners who aren't certain of their ability to judge the quality of an electrician are advised to go with a manufacturer's recommended certified installer.

The cost of installation will vary depending on installation quality, distance that wires and conduits need to run from the breaker box (a.k.a. service panel) to the EVSE, and labor rates of the electrician. Some jobs can cost as little as $200, if the EVSE is mounted next to the breaker box. Or the installation can run as much as several thousand dollars if a conduit needs to be run from another part of the house, or if new or upgraded electrical service is required at your home.

DIY is a low-cost installation option, with a big caveat: don’t take on this job if you don’t know what you are doing. It can be dangerous. Besides, local codes may require permits and inspections to be carried out on your EVSE installation.

Amperage Capacity

You should buy an EVSE that can handle at least 30 amps. The rule of thumb is that 30-amp service will roughly give you the ability to add 30 miles of range in an hour—just as 15 amps will add about 15 miles in an hour of charging. (These range numbers are somewhat optimistic.)

Keep in mind that most plug-in hybrids (and the Nissan LEAF prior to the 2013 model) don’t take full advantage of the faster rate. That’s okay. It’s still wise to have the capacity to charge at least at the 30-amp level, even if your current car can't fully utilize the higher amperage, so you don’t have to upgrade in a few years if/when you buy a new EV that has a faster on-board charger. Also, it’s nice to allow friends with faster-charging EVs to get a full charge from your garage.

Note: A 30-amp EVSE will need a circuit breaker rated for at least 40 amps.

Length of Charging Cable, and EVSE Location

Before you buy an EVSE, imagine where your electric car will be parked. Think about the ideal location for this piece of equipment. Now measure the distance between where the EVSE will hang on your wall, and where the charging port is on your car. Cables usually run from approximately 15 to 25 feet. Make sure your cord can easily reach where it needs to go, and think about its length for a potential second plug-in car in your driveway or garage.

Depending on where you locate your EVSE, an electrician might have to run just a few feet of conduit—or dozens of feet. Longer copper runs will add installation cost, but because you’ll charge almost every night, you want it to be as convenient as possible.

Portability

If it’s possible, don’t permanently install your EVSE. In other words, have an electrician install a NEMA 14-50 outlet or something similar (types of outlets used for things like clothes dryers). Then put a matching plug on a pigtail mounted to your EVSE. You can then mount your EVSE right next to the outlet, and simply plug it in. If the time comes when you move, or decide to relocate your EVSE, simply unplug it—and plug it back into another NEMA 14-50 outlet.

This approach costs exactly the same as a hard-wire installation, and makes the device instantly moveable without additional expense. If your EVSE is outside—because maybe you don’t have a garage—then local code might require that you hard-wire the charging equipment. Otherwise, keep your options open.

Connectivity

In this age of smart phones, smart grids, smart this and smart that, you might feel compelled to buy a Wi-Fi-enabled EVSE. That might not be so smart after all. While these fancier products sound cool because they have timers, meters, touch screens and capabilities for monitoring and changing charging events over the web, most long-time EV drivers believe that connectivity adds unnecessary complexity, as well as cost. In some cases, when connectivity is lost, the EVSE can shut down. Besides, many of these remote controllable features are available directly on the car, or from mobile applications. So, the smart money is on dumb but durable EVSEs.

If tracking electricity usage of your EV (for work or tax purposes) is an absolute must, you'll want to either meter your charging separately, or keep your eye open for add-on devices that perform this function via integration with the smart grid. These solutions are currently being evaluated in pilot projects.