Plug-In Vehicle Charging – What You Need to Know

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If you are shopping for a plug-in electric vehicle, your thinking is likely focused on the car and the deal. But there’s another important element, plug-in vehicle charging.

How are you going to charge the batteries, and where can you go to find a plug-in car charger?

Don’t despair, we’re here to help.

[Estimated Reading Time: 9 minutes, 30 seconds]

The first thing to know about charging a plug-in electric vehicle, or PEV, is that the most convenient and efficient way to do it is at home, overnight, when electricity rates are cheapest and you’re down for the night and not going to be needing the car.

A charging habits study by the Idaho National Laboratory several years ago found that 85 percent of all plug-in vehicle charging is done at home. The rest is accomplished with workplace charging or by using the large and ever-growing network of public chargers found at many retail, government, entertainment, hotel and restaurant locations around the country.

But plug-in vehicle charging away from home often requires payment, or advance registration with the company or program providing the charger. It also means that, unless you are staying for several hours or more, or are at a rapid-charge station (Tesla calls its a Supercharger) you won’t be getting much juice; certainly not in a 30-minute dash into the mall or while grabbing lunch at a restaurant or fast food outlet that has a plug-in vehicle charging station or two in the parking lot. More about those rapid-charge stations a later in this article.

Charging PEVs takes time, and at home is usually when you have that luxury.

Something for Free?

Depending on how much time you can devote to keeping the car plugged in, you might not need to spend anything extra to get hooked up.

All PEVs come with a 110-volt cord-set that has a standard 3-prong male plug at one end, a charging nozzle (called a J1772 connector after its SAE design standard) at the other, and a safety device on the cord in between the two. The safety monitors how much power the car is drawing and adjusts the flow of electrons to keep the cord-set from overheating. It also can shut things down if a short or other electrical problem occurs.

The problem is that plug-in vehicle charging with 110-volt current takes a really loooooog time unless your PEV has a really small battery. On average, a 110-volt, or Level 1, charging system delivers juice at a rate that adds from 3 to 5 miles of range to a PEV’s battery each hour.

That’s fine if you have a plug-in hybrid (PHEV) with 20 miles of all-electric range. You can plug it into a standard wall socket anyplace that uses 110-volt current and refill the empty battery in about 4-6 hours.

But if you have a plug-in car with a larger battery, the wait could be excruciatingly painful. Moat battery electric vehicles, or BEVs, have batteries that deliver 150-300 miles of range. That’s 16 to 60 hours or more on a Level 1 device to recharge a fully depleted battery.

Most PEV owners are likely going to be much happier with a 240-volt, or Level 2, device, which can be substantially quicker at doing the job than a Level 1 system.

Where’s the Charger, Actually?

Notice, we haven’t been calling the devices and cord-sets “chargers.”

That’s because Level 1 and Level 2 “charging stations” aren’t really chargers.

The chargers are built into the car. The thing most of us call a charger is actually known as electric vehicle supply equipment, or EVSE. It’s the cord-set that came in the trunk, or the free-standing or wall-mounted “station” you’re used to seeing PEVS hooked up to. It is the device that enables the car’s charger to communicate with the the electrical supply to control the flow of current and keep the battery pack from overheating. It is also a safety device that can shut things down if there’s an electrical short or other problem, and it anchors and stores the charging cord.

But almost everyone calls the EVSE a charger or plug-in vehicle charging station, and it’s ok if you do, too. We certainly will from here on-out.

And there is one instance in which the EVSE is a charger.

A Higher Level

In Level 3 charging, also called DC (direct current) or rapid charging, the device includes both the charger and the safety and communications equipment. It’s about the size of a refrigerator, making it pretty difficult to hide somewhere on the car. It is also very expensive compared to the Level 1 and Level 2 EVSEs, and draws 480 volts or more, making it impractical for home use.

Most Level 3 chargers are commercial charging stations installed along main highways by private and government-backed programs aimed at encouraging more PEV use by reducing what’s known as “range anxiety,” the fear of driving too far in a plug-in car and running out of power before you can make it home.

Level 3 chargers can take a BEV’s large-capacity battery from fully depleted to 80 percent charged in 30 minutes or so, and faster charging speeds are being worked on. They are intended to encourage PEV drivers to venture out on the road for longer trips or to make it easier for people with long commutes to use their plug-in vehicles.

Tesla has the largest system, enabling cross-country travel in its Model S and Model 3 sedans and Model X and Y crossovers. But Tesla’s “Supercharger” network uses a unique connector and charging protocol can’t be used by most other EVs.

Automakers don’t equip plug-in hybrids for quick charging because the systems for handling 480-volt charging would add too much cost to vehicles that don’t depend entirely on their rechargeable batteries to get you from place to place.

In the U.S. there are two DC fast-charge protocols in use for non-Tesla vehicles: the CCS system is used by all European and American brands and most major Asian marques as well; the CHAdeMO system is used by Nissan and Mitsubishi. Most of the DC fast-charge stations being installed around the country have connectors for both.

Stepping it Up A Notch-or Two or Three

If you are planning to buy or lease a BEV, you will almost certainly want to have access to a Level 2 system. You probably will want to use Level 2 charging with most plug-in hybrids as well, considering that they deliver the best fuel economy and cleanest emissions when they run most of the time on their electric motors, so ought to be charged as often as practical.

Most BEV and PHEV users have a charging station installed at home, in the garage, or, for a few lucky apartment dwellers, in their assigned parking space.

Saving time isn’t the only reason to go with Level 2. Because they are much quicker than 110-volt systems, they can save you money. A car that’s plugged into a Level 1 system at night when power rates are cheapest might still need to be hooked up well into the the next day, when rates are much higher. But most Level 2 systems will do the job in the hours when rates are lowest.

You can get home Level 2 stations that are hard-wired into your residential electrical service, or you can get models that can be plugged in to a dedicated 240-volt wall socket. The plug-in models are a little more expensive than their hard-wired siblings, and often cannot be installed out of doors, but they are much easier to mount in a garage and to take with you if you move.

Both types do require a dedicated 240-volt circuit, though, and that’s something – if your garage doesn’t already have one – you will probably want to hire a qualified electrician to install.

You can also find Level 2 cord-sets, which don’t need to be installed and can be carried in your trunk for use anywhere you can find a compatible 240-volt supply. But they typically work at a slower pace than wall-mounted stations.

Several companies are developing wireless charging systems – which require a receiver unit to be mounted on the underside of the car and a charging pad to be located on the ground (garage or parking space floor, typically). So far only one company has gone commercial, the EvatranGroup with its Plugless Power unit. Plugless has wireless chargers for Nissan, General Motors and Tesla PEVs and is developing systems for other makes and models.

Finding Home Charging Devices

Most EVSE manufacturers sell directly to the public via their websites, others list retailers who sell them. And many PEV dealerships offer factory-approved home charging devices, and even installation services.

You can also order home stations on and eBay, and on Home Depot and Lowe’s websites.

Major home EVSE manufacturers include Aerovironment, Blink, Bosch, Clipper Creek, Delta Energy Systems, Eaton, Evatran Group, EVoCharge, General Electric, Leviton and Siemens.

What’s the Cost?

You can spend a lot or a little on a home charging system – some basic Level 2 chargers can be had for under $350. Others, with high-end WiFi capability and other bells and whistles like delayed and timed charging and automated record-keeping to help you track how much power you are using to charge your car, can run well over $1,000.

Price also depends on things like the length of the plug-in vehicle charging cord (long ones let you park farther away from the unit and provide more parking flexibility), the capacity of the plug-in vehicle charging station and whether it is rated for outdoor use or is indoors only.

Capacity is the biggest factor – EVSEs are sized by their amperage – the maximum flow rate of current an electric circuit can supply. Level 2 units all are rated at 240 volts, but come in a variety of amperage ratings.

Basic units start at 16 amps, most are 30 or 40 amps, and some EVSEs can go up to 80 amps. The unit’s amperage rating, plus the capacity of the car’s on-board charger, which is rated in kilowatt-hours (kWh), determines just how fast the car can be charged.

Most professional EVSE installers recommend a minimum of a 30-amp system and many say a 40-amp system is even better. That’s especially true if you might start small with a plug-in hybrid but plan to step up sometime to a BEV with more charging capacity. A high-amp system will slow down for a car with a low kWh charger, but a low amp system can’t speed up for a model with a high-capacity charger.

What if I Don’t Want – or Can’t Have – A Home Charger?

More and more businesses are installing workplace chargers in their parking lots, and some people have found they can regularly plug in to public Level 2 chargers in nearby government and commercial facilities.

The Electric Drive Transportation Association maintains a fairly up-to-date charging station showroom that also lists plug-in vehicle charging station suppliers and commercial charging networks and providers.

The federal Energy Department’s Alternative Fuels PEV Station Locator shows almost 18,000 charging stations around the country and the number steadily grows. The locator tool provides information on each about operating hours, charging levels and models of vehicles served. Tesla’s Level 3 chargers, for instance, are only open to Tesla vehicles, and there are two competing “public” fast charging systems in use. Some Japanese brands use a system called CHAdeMO and cannot use the SAE “combined charging system” standardized for U.S. and European brands – and vice versa.

The group-sourced Plugshare app lists commercial and private plug-in vehicle charging stations in the U.S. Canada, Mexico, the Caribbean and Europe. You need to join the organization (it’s free) to access information about private chargers – many of them the home stations of PEV owners willing to offer a plug-in to travelers who need a top-up and can’t make it to a commercial station.

There’s More if You Want…

If you really want to get into the nitty gritty of EVSEs and on-board charging capacity, see our “Amps, Volts and Watts” article.

It explains how to size the home electrical service for EVSEs, how to understand car charger capacity and how to compute a system’s maximum power delivery rate.

And whether you go there or stop here, have fun looking for a charger for that PEV you’re eyeballing!

13 thoughts on “Plug-In Vehicle Charging – What You Need to Know”

  1. Heaters for J1772 plugs!

    Here in Canada we can get winters with below -40 degrees (same in both C & F). For those charging outdoors, it would seem to be possible to have a heater in the J1772 plug (even temperature controlled).

    I have had my plug freeze to my vehicle, effectively disabling it. I now carry a 12v hair dryer to defrost the plug if it happens again. I also have on order a weather cover to prevent snow/ice build-up on the plug.

    Some entrepreneur should come up with and patent a self-heating J1772 plug, and make a fortune.

  2. I just wanna thank you for sharing your information and your site or blog this is simple but nice article I’ve ever seen i like it i learn something today.

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