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A Simple Guide to DC Fast Charging

Image: Kārlis Dambrāns (www.flickr.com/photos/janitors/15880277443/)

Range anxiety has long been cited as the most significant factor standing in the way of widespread adoption of electric vehicles (which we first talked about in 2011). The truth is though, every consumer vehicle on the market has a limited range – whether it’s powered by gas or electricity.

The real difference between electric cars and internal combustion vehicles is the amount of time and effort it takes to refuel them. If you unexpectedly notice your Prius is running low on fuel, finding a gas station and filling up will rarely set you back more than 10-20 minutes. Even more rare is a situation where you might legitimately fear running out of gas.

For electric vehicle owners, things are a bit more complicated. Adding 80 miles of range can take almost a full day if you don’t have access to a 240-volt Level 2 charging station. If you do have access to one, that charge can still take up to 8 hours. Dealing with these limitations requires planning and accepting the fact that there are some places your car can’t take you in a reasonable amount of time.

This doesn’t necessarily have to be the case though…

Introducing DC Fast Chargers (also known as DC Quick Chargers)

DC Fast Chargers supersede Level 1 and Level 2 charging stations, and are designed to charge electric vehicles quickly with an electric output ranging between 50 kW – 120 kW.

Most modern fully-electric vehicles can be equipped with DC quick charge (DCQC) capability, and there are currently nearly 2,200 high-speed chargers in the United States capable of adding significant range to an EV in not much longer than the time it takes to fill your gas tank.

Source: afdc.energy.gov

Tesla owners also have exclusive access to a nationwide network of Superchargers connecting most major cities in the country (map down below). Adding 170 miles takes just 30 minutes at a Supercharger station—enough time for a bathroom break and a stop at the drive thru. An additional 40 miles will cost you just 10 more minutes—enough time to sit down and eat.

This isn’t to say adding electrons to a Nissan LEAF is as convenient as refilling a Ford Taurus, but if DCQCs were as widely available as fuel pumps, the perceived inconvenience of owning an EV would diminish significantly.

In Japan—a country less than 5 percent the size of the United States—there are more than 6,000 DCQCs, all of which are compatible with the vast majority of Japanese EVs. That’s roughly one quick-charge station for every 245 square miles compared to the U.S.’s one per 2,235 square-mile concentration.

We put together a quick PDF that links to some other helpful resources around DC Fast Charging, including a general overview, station hardware providers, where to find a public station, and a list of vehicles that are quick charge capable. You can download that PDF here.

Why Can’t All EVs Just Use the Same Network?

Remember that drawer filled with nine tangled cell phone chargers that you hung onto “just in case?” As is common with new technologies, electric vehicle makers don’t agree on which charging standard is best to quick-charge a plug-in vehicle. Right now, nearly all EVs that offer DCQC capability in the U.S. use one of three standards. Many analysts predict that all three standards are likely to coexist in the U.S. indefinitely.

 


CHAdeMO

In 2010, Toyota, Nissan and Mitsubishi partnered to establish the CHAdeMO quick charge standard. Most current CHAdeMO chargers have charge speeds of 40 – 60 kW, which is fast enough to charge a Nissan LEAF to 80 percent in about a half hour. In the future that could rise to as high 100 kW as improvements are made to the technology.

Nearly all of Japan’s DCQC stations are CHAdeMO. In the U.S. they make up nearly three quarters of the existing quick charge infrastructure. Worldwide, CHAdeMO passed the 10,000 station mark in late 2015, making it by far the most popular standard. So why can’t everyone just agree to use CHAdeMO so we can get to work building out the infrastructure?

 


Combined Charging System (CCS)

In late 2011, a second quick charge standard entered the fray. The Combined Charge System standard got its name because it built on the existing J1772 Level 2 charge standard to allow for all three speeds of charging from a single port. (In CHAdeMO vehicles, the Level 2 and DCQC ports must be placed side by side to allow for multiple speeds.)

Spearheaded by American and European carmakers, CCS chargers improved several of the practicality and cost issues associated with CHAdeMO while allowing for a higher potential rate of charge. While existing CCS chargers typically run at the same speeds as CHAdeMO, the standard allows for a theoretical maximum of 350 kW through the port—more than twice as fast as a Tesla Supercharger.

The Combined Charging System was relatively late to the game, with the first public test station having been installed in summer of 2013 in Germany. Since then, not a lot of progress has been made in building out a network in the U.S., where the total number of compatible stations stands at fewer than 400. CCS is usually provided alongside CHAdeMO at the same station (though less than a third of CHAdeMO stations offer CCS.) With a number of new CCS-enabled EVs scheduled to hit the market soon though, the CCS network is expected to steadily expand in the next few years.

 

Tesla Supercharger

Although the underlying technology in the CHAdeMO and CCS standards could one day facilitate charge speeds of 100 kW and 350 kW respectively, you’re unlikely to find either standard offering more than 60 kW right now. Instead of waiting for these improvements, Tesla decided to move forward with its own DCQC standard, the Supercharger, which has provided 120 kW of power since its launch.

What’s more, Tesla was strategic about where it placed the more than 250 Supercharger stations currently in its network—providing drivers with the coverage they need to drive cross-country or between major cities. This is possible because the Model S is currently the only 200+ mile EV on the market, where cars like the Nissan LEAF and BMW i3 would need stations placed at intervals of 80 miles or so along each highway.

 

Tesla’s U.S. Supercharger Network

The Drawbacks of a Fast Charge

As might be expected, installing a public DCQC costs considerably more than adding a Level 2 charging station. First, there’s the cost of the station itself, which has decreased in some instances by more than two thirds over the last five years. Where the earliest CHAdeMO charging units could cost upwards of $35,000 when the technology first hit the market, Nissan currently offers one for less than $10,000. BMW sells its CCS charger for less than $7,000.

Unfortunately, stations themselves are just fraction of the total cost burden associated with installing a DCQC. A 2014 survey by the Rocky Mountain Institute placed the real price of each new quick charge station at $50,000 – $100,000. Labor, permitting and the installation of a 480-volt transformer ($10,000 – $25,000) accounted for roughly two thirds of the final cost. Using this math, it would require an investment of as much as $600 million just to cover the state of California with enough quick chargers to match Japan’s concentration— and that’s ignoring the added cost of providing for multiple standards at each station.

Then there’s the consumer cost of the DCQC charge port on the car itself. More than half of EVs with quick charge capability offer it as an option and not a standard feature—usually adding upwards of $700 to a model’s sticker price. Until quick-charge stations become more common, there are few non-Tesla drivers for whom that add-on makes a ton of fiscal sense.

Installing a fast charger can be very costly.

What’s Next For Quick Charging?

The strategic placement of the Supercharger network provides a look at what DCQC could one day mean for plug-in drivers. With the next generation of affordable EVs on their way, a trip between San Francisco and Los Angeles in the forthcoming 200-mile Chevy Bolt could be made possible by a single stop for a meal around the halfway mark.

The importance of quick charging isn’t in responding to the needs of current EV drivers but anticipating tomorrow’s needs. Unfortunately, many of the existing DCQC stations are installed at car dealerships and concentrated around cities, where EV drivers have so far been getting by pretty well charging mostly at home. This isn’t to say that making quick charge stations as ubiquitous as gas stations wouldn’t revolutionize plug-in driving.

Mitsubishi’s Outlander PHEV, for example, is available with quick-charge capability in Japan but Mitsubishi recently announced that it won’t offer the option in the U.S.

In fact, there are currently no plug-in hybrids sold in the U.S. with a DCQC port. This is more a reflection of the added cost of the feature and limited availability of infrastructure than demand from drivers. A recent survey by one of the nation’s leading charge providers, NRG eVgo, found that given the option of both chargers at a single site, drivers preferred DCQCs 12-to-1 over Level 2 charging.

As Tesla realized though, the more immediate need is allowing owners to increase the distance they can drive in a given day without an extended period of charging—not attracting existing drivers to dealerships or shopping centers already within range of their homes.

The Japanese achieved their high concentration of DCQC availability thanks to a private-public partnership that saw the number of stations in that country quadruple in less than two years. There aren’t currently any programs this ambitious in the United States, but the promise of quick charging is great—and the opportunity to create new networks that might one day replace gas stations could be even greater.

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