EV Charging 101

As a society over the last 100 years or so, we’ve become used to the notion of filling our cars up with gasoline every few days. Now, as we start to make the switch to electric vehicles it’s going to take quite an adjustment to switch that mindset to charging our electric cars with electricity.

In this article we’ll take you through the basics of electric vehicle charging, from home charging equipment to public charging stations, from how long it takes to how much it costs. And we’ll talk about some of the shifts in our thinking we’ll have to undergo as to how and when is the best time to charge.

Three Levels of Charging

Before we get too deep into the different levels of charging, it’s important to recognize the difference between AC and DC power. Electric vehicles require DC power. Almost everything else in the average consumer’s world runs on AC. 

So when an EV is charged at home, where 86% percent of EV charging is done, the power needs to be converted from AC to DC via the vehicles’ on board inverter. 

With all that said,, there are three different levels of charging – Level 1, Level 2 (AC) and Level 3 (DC) fast charging. All electric vehicles can charge at any of the three levels, as long as they have the appropriate connector (more on that later). Which one you use depends on what you’re looking for your immediate charging needs.

Level 1 Charging

Level 1 charging does not require anything more than a basic 110 volt wall outlet to charge the vehicle. The outlet should be positioned close enough to where you park so that you don’t need to use an extension cord – such as inside a garage or right next to the driveway.

Level 1 charging is a practical choice for many suburban homes since the necessary equipment is likely already installed and installation costs are usually affordable. Unfortunately, this method of charging can be quite slow; it may take up to 24 hours to charge an electric car or provide around 4-6 miles of range per hour.

For drivers who only use their cars for a relatively short commute and to run errands around town, it’s a perfectly good way to top up your car overnight without having to spend a lot on electrical upgrades.

For a Level 1 electric vehicle charger, you’ll be able to use the home’s pre-existing electrical wiring.

Level 2 Charging

With a relatively simple electrical upgrade, Level 2 can offer a much faster option for home charging. It requires a 240 volts outlet, similar to those used for high-powered appliances such as electric stoves or tumble driers. But for Level 2 charging, you will likely need a dedicated circuit.

Most suburban houses have at least one of these outlets installed already, although it’s more likely to be located in the kitchen or the laundry room than in the garage or on the driveway. Getting one installed is relatively easy and inexpensive, though. Any qualified electrician can do it.

This would allow you to charge a typical electric car at a rate of 25-30 miles per hour, which is enough to fully recharge overnight or during a typical workday if it’s located at your place of work.

Level 3 Charging

Level 3 charging is the quickest way to recharge an EV, typically allowing you to fully recharge in under an hour. These are not available for home use but are primarily found at public charging stations and at rest stops along highways, where you can refuel quickly, grab a quick bite to eat, and be back on the road without too much delay.

Tesla has the largest (and arguably the best) network of Level 3 charging stations in the world, where Tesla owners can fully charge a battery in approximately 40 minutes. While these are currently only available to Tesla owners, there is pressure and no small amount of financial incentive available to try and persuade Elon Musk to open up the network to other makes of electric vehicles.

In addition to Tesla, a huge number of level 3 and level 2 public charging stations is being constructed rapidly throughout the country to assure would-be EV owners that the charging infrastructure is going to be there when they need it.

EV owners will soon have a wealth of fast charging options available to them shopping centers, universities, stadiums, and beyond.

Bidirectional EV Charging

A bidirectional electric vehicle charger is an advanced EV charger that can both charge and discharge energy from an EV battery. With unidirectional (one-way) EV chargers, electricity flows just from the power grid into the vehicle. With bidirectional (two-way) chargers, electricity can flow both ways.

A bidirectional electric vehicle charger is a more advanced type of EV charger that can both dispense and receive energy from an EV battery. Unlike unidirectional (one-way) chargers, which only allow electricity to travel from the grid into the vehicle, bidirectional (two-way) chargers enable electricity to flow back and forth.

In other words, not only can you charge the vehicle from the house, but you can also power the house from the vehicle. This has profound implications for how we consume electricity in the future.

It gets a little ahead of EV Charging 101 but watch this space. Bidirectional charging will be a big deal in years to come.

Four Types of Connectors

As often happens when a new technology first becomes popular, competing brands make products that are incompatible with one another (think VHS and Betamax from the early days of video recorders). Eventually, either one brand wins in the marketplace or government regulators step in and impose a single standard.

EV charging is still going through that “battle for the standard” phase and so, until one brand wins out, there are currently four different types of connectors, none of which are compatible with the others.

J1772 Connector (J Plug)

All EVs sold in the United States, except for Tesla, use a J1772 plug, (also known as a J-plug) for Level 1 and Level 2 AC charging. This plug is suitable for home use as well as at public level 2 charging stations found at work places, malls or municipal parking lots.

CHAdeMO

CHAdeMO is short for “Charge de Move”, which, despite its French-sounding name, was developed by a collection of auto industry groups, mainly from Japan. As such, leading Japanese companies such as Toyota, Nissan and Mitsubishi prefer the CHAdeMO standard.

CSS

The Combined Charging System or CCS connector is an open industry standard that has been implemented by vehicle manufacturers across the globe. Primarily used in North America and Europe, this connector is set to become the go-to for newly manufactured passenger EVs in those regions.

Tesla

Tesla, being one of the first EV manufacturers to hit the market with fast-charging cars, designed its own connector type. So the Tesla connector works only on Tesla vehicles.

That fact not only prevents Tesla drivers from using non-Tesla connectors without paying extra for an adapter, it also excludes all non-Tesla drivers from using what most agree is the best charging infrastructure in the world, Tesla’s Supercharger network.

How Long Does it Take to Charge an EV?

Rather like asking how long a piece of string is, asking how long it takes to charge an electric vehicle is an incomplete question because charging time depends on a number of different factors. 

In fact, it can take anywhere from 20 minutes to 4 hours to fully charge an electric car, depending on how you go about it. 

The first factor, of course, is whether you charge using level1, level2 or level 3 charging equipment. This is the input power and, as you might expect, the faster you can put power into the battery, the quicker it will charge.

The second factor is whether you’re charging with DC or AC power. SInce cars run on DC power, you can expect a DC charger to charge more quickly than an AC one. That’s because the power does not need to be converted by the vehicle’s onboard inverter. 

Even within the realm of AC chargers, charging times can vary because the inverters for different vehicles have varying capacities and, therefore, can accept AC charge at different rates. 

Another factor in charging times is temperature, both of the battery itself and of the vehicle’s surroundings. When charging, a battery generates heat which can be exacerbated in warm weather. 

To prevent damage from overheating, EVs are built with an internal battery management system to moderate the battery’s temperature. If it detects that the temperature is becoming too high during charging, it will lower the charging speed accordingly.

FInally, there is the size of the battery. Larger batteries will typically take longer to charge, although, again, those longer times might be offset by a more efficient converter.

Final Thoughts

The concept of filling the car up at a gas station has become so ingrained in our collective consciousness that it seems hard to believe that it will soon become as much a thing of the past as rewinding the video cassette before returning it to Blockbuster.

In its place will grow a whole new habit around charging our cars either at home or at a public charging station. I hope this article has given you a better understa ding of what that future world will be like.