More drivers every year are saving major money by switching to electric cars. Not only do the earnings from never having to buy gas stack up quickly, the repair expenses are much lower in the long-run, since electric cars have far fewer moving parts than combustion vehicles. As more electric vehicle (EV) models go on sale, and support infrastructure expands, it's becoming easier and easier to make the switch.
One of the best ways to save money with your EV is to charge it at night, when energy costs are lowest. That means installing a charger in a garage or parking space.
Safety Note: While relatively straightforward, this project can be dangerous. If you don’t have much electrical experience, you may want to hire a professional.
Electric Car Charger Basics
First, know the rules. In America, installations are subject to National Electrical Code Article 625, which includes details about where you can mount a charger and what wires are acceptable to use. Wherever you are, check your national and local codes. Many municipalities require professional certification of electrical systems.
All electric cars come with a basic, 120 volt charger, which can connect to regular power outlets. The energy draw is limited, though, so charging is pretty slow (as much as four to six times slower than with a 240 volt "level two" model).
Upgrading to a 240 volt charger will probably require a home installation (like the wiring for many dryers and stoves), which as of this writing will cost between $500 and $1,000 for the equipment and $200 to $2,000 for professional labor.
The upfront expense may well be worth it for the convenience if you have a larger EV. However, if your commute is short and you rarely drive long distances, you might be able to meet all your needs with a regular outlet charger.
On the other end, chargers do get even faster. Loosely defined "level three" and "DC" (direct current) chargers, can move things into the 500+ volt range, though for now they're restricted to public or commercial locations in most areas.
Prepare Your Home
Your home has to be ready to handle the burden of the extra electrical current your car will draw, so your first challenge is to figure our how much your system can handle. If you need more juice, you’ll have to cut the power of your house off, install a new meter, and put in a new breaker panel.
While you're going through this process, consider whether you might ultimately want to be able to support multiple EVs on your property. Doing all the installation work again in a few years when there's a second EV in the home will be a hassle.
If your garage is old, or far from the house, you may need to replace some wiring to eliminate the risk of fires. If you don't have a garage, you can install a charger in the driveway (look for a NEMA rating of 4X, which will guarantee protection from the elements).
Choose the Plug and Location
All electric cars except Teslas use the SAE-Standard J1772 plug. These are available in 16 amp and 30 amp varieties (16 may be enough if your car is on the smaller side, 30 is enough to efficiently charge larger batteries). Tesla connectors come in a range of options, from 15 to 100 amps. The J1772 has four elements—power delivery, grounding, connection detection, and communication with the car about charge level.
Cord length will affect the price, so do some tests to see how close you can get your car to the planned plug location. It's better to do this part once you know for sure what kind of EV you'll be charging, since their ports are in different places.
If you’re going with a charger in your garage, you may want to choose a spot close to the door. That way, you can charge your car whether it’s parked in the garage or the driveway.
Install the Bracket
Once you have your spot and equipment, fix the charger bracket to a wall using a level and drywall anchors.
Turn off the Power
Once you're ready to get the wiring underway, it’s crucial for safety that you turn off the power of your home. Turn off all your breakers, including the master.
Install a Double Pole Breaker
To get 240 volts, you'll need to use an insulated four-strand cable to essentially combine two buses of 120 volts each. As mentioned above, it's possible that this will require replacing your breaker, though some newer boxes have interfaces to connect double-pole breakers directly.
To connect the buses manually, you'll attach a ground wire to the ground bus bar (a strip of metal that handles local, high-current power), a common wire to the wire bus bar, and two hot wires to the double-pole breaker.
Run the Wires and Affix the Charger
Feed the cable you've run from your new 240 volt connection through the cavity in the bracket. The charger wiring will be fairly straightforward and should be clear from the accompanying instructions. This bracket will safely hold the power flowing from your system so the charger itself isn't live unless it's plugged into your car.
Finally, connect the charger to the bracket, attaching the wires to the correct areas inside. These should be clearly marked and simple to connect. The black and white wires on these chargers can usually be interchangeably attached to L1 and L2.
Turn the Power Back On
Now it’s time to test out the charger—turn the power back on and plug in the car! Most manufacturers recommend regularly setting your charge to about 80% to avoid stressing the battery.
From now on, you can power up your electric car each night while you sleep, saving money and time, and making the world a safer place.
Now that you're getting your transportation energy from your home power system, you might be especially excited about adding some renewable sources to the mix, such as solar or wind. Every tiny bit of energy you collect for free will make your car even cheaper to drive.