Fast Electric Car Charging Is Slowly Picking Up Speed

By · April 13, 2011

AeroVironment's futuristic DC Fast Charge station

AeroVironment's futuristic DC Fast Charge station.

While electric vehicles are only being delivered by the hundreds today, plans for clusters of fast DC charging stations around major cities and along highways are fully underway. During the next 18 months, it may be more of a challenge to find enough cars to warrant the chargers' existence than it will be for EV drivers to find a fast charge station.

DC chargers (which are not Level 3 chargers, as some folks mistakenly have called them), can charge a vehicle at up to 10 times faster (50-80 kilowatts) than the top Level 2 rate. They are being installed across the country, largely thanks to you, the American taxpayer. The theory is that knowing that there exists a place where you can charge in less than half an hour is a great pacifier for prospective EV owners who would otherwise be susceptible to "range anxiety."
In Oregon, a federally-funded contract was recently awarded to AeroVironment to install 8 chargers along highway 5 in the southern part of the state. At $80,000 per installation, the freedom to drive electric to Ashland comes at a significant cost. Another federal grant will see up to two dozen fast charging stations in northwest Oregon.

Similarly, San Diego (60 DC chargers), San Francisco (20), Philadelphia (22) as well as Chicago and Houston are also in the midst of installing equipment, mostly subsidized through state or local grants.

DC charging faces an uphill battle not only because of the high cost, but also because of a lack of compatible EVs and the potential impact on the grid. Thus far only the Nissan LEAF can work with the fast chargers if buyers request the DC charging option be installed at the factory at a cost of at least $700. Plug-in hybrids like the Chevrolet Volt and upcoming Toyota Prius Plug-in Hybrid don't have much need for DC charging given their smaller batteries, and the Coda Electric Sedan won't support DC charging either. The Mitsubishi i-MiEV will have a DC option when it arrives in select markets at the end of the year.

The emphasis for Level 1 and 2 charging has been on smart charging EVs by managing the flow of electricity to emphasize off-peak charging. DC charging is the antithesis of this concept since it is high power, and usually not overnight. The good news is that using battery storage creates a buffer against peak DC charging. Several vendors, including hardware companies and automotive OEMs, that participated in last week's EV Infrastructure USA conference in San Diego acknowledged that storing energy off-peak in batteries connected to charging stations is a necessary part of the DC charging equation.

There was considerable debate about the efficacy of Level 2 charging, which is the vast majority of the equipment currently installed, with folks arguing that DC charging or even charging via a standard 110V outlet as more cost effective solutions. 350 Green, an EV charging services company that has landed several large contracts in U.S. cities, claims that DC charging is cheaper to deliver by the kilowatt—but that assumes a steady flow of customers during the day and into the evening.

DC charging will likely grow even faster once the Society of Automotive Engineers (SAE) chooses a standard. The equipment currently being installed is based on the CHAdeMO internationally-supported hardware specification, but SAE has been dragging its wheels in acknowledging CHAdeMO or picking another standard, which would be fairly disastrous for the industry.

Comments

· VoltFanSite (not verified) · 3 years ago

Nice to see charging stations along the highway but I would like to see level 2 charging station at restaurants.

· · 3 years ago

why is "SAE has been dragging its wheels"?

· Scott (not verified) · 3 years ago

In your second paragraph you state that a DC fast charger is not the same as Level 3 charger. My understanding is that is exactly what a level 3 charger is. Can you explain?

· JJ - from Canada (not verified) · 3 years ago

This is crazy!
They're installing chargers that are incompatible with most of the EV's being sold!

They should have a key pad on the charger and the driver punches in a code that tells the charger what car model and battery they have and the charger would adapt the output to your model car and battery.

· · 3 years ago

The majority of the DC chargers being installed globally are based on technology developed by Tokyo Electric Power Co. which is now supported by dozens of companies in Asia and Europe via the CHAdeMO designation. The DC charge options for the Nissan Leaf and the Mitsubishi I-MiEV are CHAdeMO equipment. Levels 1-2 AC charging are standards from the SAE, which is developing Level 1-3 DC standards, but has not given any indication that CHAdeMO would be its technology of choice. So there is no "Level 3" until SAE deems it so. There has been grumbling in the industry since there is international support for CHAdeMO, as well as the chargers currently being installed courtesy of the DOE in the U.S.

· · 3 years ago

The problem with CHAdeMO is that it only supports up to 50 kW charging.
Tesla, for one is not going to accept such a pathetically slow charging rate. That rate only gets you about 190 miles of range per hour of charging. Tesla (and their customers) wants you to be able to charge their upcoming Model S for about 240 miles of range in 45 minutes. That allows a 45 minute food and recharge break every 4 hours. This will take at least 80 kW of charging speed.
If CHAdeMO is adopted by SAE as Level 3 then Tesla and anyone else who really wants to make convenient EVs that can truly replace ICE is going to, yet again, have to go it alone in order to offer their customers what they really want.

· · 3 years ago

Thank you for clearing up the 'level 3' issue. It prompted me to look into SAE standardards and now I understand that we need to be even more specific when discussing charging levels. As there are
actually AC level 1,2,3 and DC level 1,2,3 standards specified. What we refer to as a level 2 charger in our garage is more specifically an 'AC level 2'. Someday when battery packs are more standard, a DC level 2 charger for the garage may make more sense and be faster

· · 3 years ago

@scottinwashington,
There has always been a battle between AC and DC charging. With DC charging, all of the current and voltage control is done in the offboard EVSE while in AC charging, AC is generally provided to the car and the charging circuitry in the car controls the power.
Fast charging requires a lot of heavy, iron transformers and inductors so doing all the work offboard is the only way that makes sense. Slower charging is more of a question and battle between whether the car manufacturer or an infrastructure provider sells you the charging circuitry since the can feasible fit in either place.
SAE, of course, is dominated by the car companies so you can probably guess who they'd like you to purchase from, hence the fact that their levels 1 and 2 are AC. I guess they haven't found a suitable level 3 solution so that's still on hold.
In the meantime, from the infrastructure side, DC fast charging has been proposed although I don't know that anyone has arbitrarily set up any official 'levels' yet. With AC, generally: Level 1 uses ordinary household 120v power, Level 2 uses ordinary household 240v power (a little harder than 120v but existing in most US houses. Level 3 would require very high voltage and current levels not normally found in a US house. These are easy levels for AC. DC is a bit less clear.
I'm suspecting that in the end, we may specify DC chargers simply based on the kW that they can provide and the connector type/protocol with the car (eg 50 kW CHAdeMO).
IMHO, the biggest problem with DC fast charging is that car companies oppose it since it will put EVs on par with ICE (actually way ahead of them) in terms of functionality.

· · 3 years ago

Looks like Norway just went with Chademo.

http://electricaid.ning.com/profiles/blogs/energycompany-ishavskraft-2500

· · 3 years ago

Where can we find the map or location of "planned installations for San Diego (60 DC chargers), San Francisco (20)"? When will they be installed and available? What is the cost of charging?

· DarkStar (not verified) · 3 years ago

CHAdeMO currently supports about 400 volts at 200 amps (80 kW), however for a 160 kWh battery I could understand the problems with such a lengthy charge.

Luckily, vehicles like the Nissan LEAF have about a 24 kWh battery and on a CHAdeMO charger get a 0-100% charge in about 40 minutes, 0-80% in 25 minutes. But really though, who will be pulling in on fumes? (I don't know what the electric equivalent of "fumes" would be)

If I pulled in with about 50% charge, I could plug into a CHAdeMO DC Quick Charger, run in to grab a bite to eat (maybe a coffee or something) and by the time I got back out to the car it would be at 100% state-of-charge. That's exactly what we need to make electric vehicles successful.

· Jim McL (not verified) · 3 years ago

When the author says "DC chargers ... are not Level 3 chargers" I believe he is making a distinction without a real difference.

In SAE J1772, there is a definition for AC Level 3, AC Level 2, AC Level 1, and DC charging. There is no definition for "Level 3" without a prefix. By that technical standard, there is no such thing as "Level 2" which the author keeps referring to.

So while he may be technically correct, if "Level 3" has taken on the colloquial meaning of "greater than 18 kW", then what is his point? DC or AC means little to the user especially since AC Level 3 has never been implemented. (Page 34 of J1772 Jan 2010 says AC Level 3 is historical information for reference only.)

I also question your math. You say "Level 3 chargers ... can charge a vehicle at up to 10 times faster (50-80 kilowatts) than Level 2". Since AC Level 2 is defined up to 19.2 kW (and implemented up to 18 kW by Tesla and ACP), how do you calculate that DC charging is ten times faster? Looks like about two to four times faster, if your 50-80 kW range is correct.

See figure 7, page 17 of SAE J1772 Jan 2010 for max AC Level 2 current.

Are you DC charging comparing to the 6.6 kW internal chargers in the first crop of mass market EVs that were limited at the behest of electric utilities who are not up to speed on smart grid technology?

CHAdeMO does not use a heavy safety ground wire but depends on a type ground fault interrupter. SAE will likely go with a ground that can carry full fault current. The US market is litigious. I don't see this as a "disastrous" situation, but simple market adaptation.

Maybe the author has never been sued?

· · 3 years ago

@Darkstar,
It really doesn't matter how big your battery is. Charging a 25 khr (100 mile) battery in 30 minutes gets you no further than Charging a 50 kWhr (200 mile) in 30 minutes. The issue is really how long does it take to charge enough to get where I need to go. Faster (higher power) is always better from the standpoint of the driver (with that rare exception of the person who really likes waiting for a car to charge). The only reason for charging slower is to save money on either the battery or your grid connection.
The 50 kW limit for CHAdeMO was told to me by someone who should know but I haven't been able to confirm. Can you point to any definitive references that describe the CHAdeMO limitations?

· Jim McL (not verified) · 3 years ago

scottinwashington, where did you find a reference to "DC Level" x charging in any SAE document? I don't find it anywhere in J1772, nor J2293-x.

DarkStar, keep in mind that the last 20% top off of the battery generally cannot be charged faster than "Level 2" rates, without damaging the battery. That is why they always give a time to 80% because after that it has to slow down. The last few % at least are more like "Level 1" rates. On a car like the Tesla, which allows you to occasionally use more of the usual battery capacity, the last 10% or so might be VERY slow. (Any Tesla owners out there to clarify?)

ex-EV1 driver, I believe you are correct that Chademo is not fast enough for Tesla. The historic AC Level 2 allowed up to 96 kW, and J1772 DC charging allowed up to 240 kW (that is 400 amps at 600 volts). Nobody ever implemented these, and SAE DC charging standards are back under development. But I bet there is more than passenger cars under consideration. Class 8 heavy trucks, busses, etc. all have EVs on their radar.

· Max Reid (not verified) · 3 years ago

Why not we install this charger every 100 miles. So from East to West it will be 30 (3000 miles / 100) and from North to South it will be 10 (1000 miles / 100).

30 * 10 = 300.
So someone with an EV can make a coast to coast trip to show that we can do it.
Later this can expand to a charging station every 50 miles and then every 10 miles and EV revolution will begin.

· · 3 years ago

I think it is a waste of money using tax dollars putting in these fast chargers before the SAE standard if finalized. These chargers need to be a long term investment. Unfortunately, governments don't tend to have long time horizons, and throw money around like it grows on trees.

· JJJJJJ (not verified) · 3 years ago

Michael is right, $80,000 for something that may be obsolete in 6 months? What a disaster

· · 3 years ago

My reference to DC Charging being up to 10 times faster than Level 2 refers to the current chargers being installed today, which offer up to 7.2 kw. The practical L2 limit is 3.3 kw if you own a Leaf or Volt. Also, just because some people use the word Level 3 to describe CHAdeMO charging equipment doesn't make it true, it makes it "truthy."

· Jeff Wishart (not verified) · 3 years ago

A couple of points:

The author is correct that Level 3 and DC chargers are not synonymous. Level 3 can refer to both AC and DC chargers. In presentations, SAE people have provided the following chart:

AC:
Level 1: 120 VAC, single-phase, Max 16 A, Max 1.9 kW
Level 2: 240 VAC, single-phase, Max 80 A, Max 19.2 kW
Level 3: TBD; may include AC three-phase

DC:
Level 1: 200-450 VDC, Max 80 A, Max 19.2 kW
Level 2: 200-400 VDC, Max 200 A, Max 90 kW
Level 3: TBD; may cover 200-600 VDC, Max 400 A, Max 240 kW

But the response to the quote "DC chargers (which are not Level 3 chargers, as some folks mistakenly have called them), can charge a vehicle at up to 10 times faster (50-80 kilowatts) than the top Level 2 rate" that the author gives is unsatisfactory since 6.6 kW on-board chargers are already coming out (on the Coda vehicle), and the generation II versions of the Leaf and Volt (and probably Focus) will almost certainly have them. Why muddy the waters unnecessarily? At the very least, the author should say that DC chargers being installed today are approximately 15 times faster than the on-board chargers currently allow for AC charging.

· Jeff Wishart (not verified) · 3 years ago

A few points:

The author is correct that Level 3 and DC chargers are not synonymous. Level 3 can refer to both AC and DC chargers. In presentations, SAE people have provided the following chart:

AC:
Level 1: 120 VAC, single-phase, Max 16 A, Max 1.9 kW
Level 2: 240 VAC, single-phase, Max 80 A, Max 19.2 kW
Level 3: TBD; may include AC three-phase

DC:
Level 1: 200-450 VDC, Max 80 A, Max 19.2 kW
Level 2: 200-400 VDC, Max 200 A, Max 90 kW
Level 3: TBD; may cover 200-600 VDC, Max 400 A, Max 240 kW

But the response to the quote "DC chargers (which are not Level 3 chargers, as some folks mistakenly have called them), can charge a vehicle at up to 10 times faster (50-80 kilowatts) than the top Level 2 rate" that the author gives is unsatisfactory since 6.6 kW on-board chargers are already coming out (on the Coda vehicle), and the generation II versions of the Leaf and Volt (and probably Focus) will almost certainly have them. Why muddy the waters unnecessarily? At the very least, the author should say that DC chargers being installed today are approximately 15 times faster than the on-board chargers currently allow for AC charging.

Finally, in all of the discussion about fast charging here, there hasn't been anything related to battery degradation associated with faster charging. While nobody has good data yet, it's expected that charging at elevated power levels will cause more battery degradation, and this must be considered when choosing what kind of charging to use.

· Jim McL (not verified) · 3 years ago

Jeff Wishart, can you give a reference where SAE has referred to "DC Level x"? I do not see it in the specs. This just lends credence to the idea that even engineers in the EV arena use these terms loosely. What goes up on someone's power point slide does not make it a defined term in the "recommended practices" that SAE publishes and charges money for.

· · 3 years ago

Good points Jim McL,
Clearly none of these terms are gospel and will likely change a lot over the next few years as the market matures.

· · 3 years ago

@ex-EV1 driver,
I think you are right about CHAdeMO being limited to 50 kw. I saw this figure in a presentation by SAE last year.

· Anonymous (not verified) · 3 years ago

Hi I have a Leaf EV and I'm in WA state. Do you know the current state of plans for putting level 3 chargers along the I-5 corridor?

New to EVs? Start here

  1. Electric Cars Pros and Cons
    EVs are a great solution for most people. But not everybody.
  2. Seven Things To Know About Buying a Plug-In Car
    A few simple tips before you visit the dealership.
  3. Incentives for Plug-in Hybrids and Electric Cars
    Take advantage of credits and rebates to reduce EV costs.
  4. Buying Your First Home EV Charger
    You'll want a home charger. Here's how to buy the right one.
  5. The Ultimate Guide to Electric Car Charging Networks
    If you plan to charge in public, you'll want to sign up for charging network membership (or two).
  6. Electric Vehicle Charging for Businesses
    How do you ensure that electric car owners will be happy with every visit to your charging spot?
  7. How to Use the PlugShare EV Charging Station Tool
    Locate EV charging stations and optimize their use with a powerful mobile app.
  8. Quick Charging of Electric Cars
    Add 50 to 60 miles of range in about 20 minutes. Here's how.
  9. The Real Price of EV Public Charging
    Compare the cost of charging on the road to what you pay at home.
  10. Electric Vehicle Charging Etiquette
    Thou shalt charge only when necessary. And other rules to live by.