The Basics of Electric Vehicle Public Charging

By · December 20, 2012

Most electric vehicle owners charge their cars at home overnight. But charging on the road allows you to drive more than the range of a single charge. To cover the basics, we’ll explore the types of charging, how to find public charging stations, and the best way to plan a trip.

Types of Charging

There are three different types of charging supported by modern EVs.

Level 1

This is the slowest and most accessible type of charging, which uses the common U.S. household outlet. You'll need the cord set that generally comes with a new EV purchase. For a plug-in car like the Nissan LEAF or Chevy Volt, a Level 1 charge, sometimes called "trickle charge," will provide about 4 to 5 miles of range per hour of charging. That’s not very helpful for a quick stop, but you can find these outlets nearly anywhere you stop. Level 1 is sufficient for locations where your car will be parked for long periods such as a workplace, an overnight hotel stay, or long-term airport parking.

Nissan LEAF charging ports

The Nissan LEAF SL model has two charging inlets—one for the CHAdeMO quick charging standard (left), and the J1772 inlet (right) for both Level 1 and Level 2 charging.

Level 2

This is the most common type of EV infrastructure currently being installed. These stations are the same voltage as a home dryer outlet. Equipment at these stations have the J1772 connector, so you won't need to bring any equipment. You will, however, most likely need a membership card to initiate the charge. (See below for a list of these networks.)

These stations provide anywhere from 3 to 6 times the charging rate of a Level 1 station. To know how fast a Level 2 station will charge your EV, you'll need to know one detail: the rating of your vehicle's on-board charger. This is typically either 3.3 or 6.6 kilowatts.

The 2011-2012 Nissan Leaf has a 3.3-kW charger, while the 2013 model has a 6.6-kW charger. Check your owner's manual for your vehicle for the charger's rating. A 3.3-kW charger will provide a typical plug-in car with an additional 12 to 15 miles of range for each hour of charging. At this rate, a long lunch or similar stop, perhaps at your destination, can provide you with the range for the next leg or return trip. A 6.6-kW charger, much more useful, will give you 24 to 30 miles of range per hour.

DC Fast Charging

You might have assumed after Level 1 and Level 2, that the next step up would be Level 3. That might have been true if fast charging had been universally standardized. Unfortunately, that hasn’t happened yet.

Japanese manufacturers Nissan and Mitsubishi support a standard called CHAdeMO—while BMW, Daimler, Ford, General Motors, and Volkswagen teamed up with the Society of Automotive Engineers (SAE) to create a standard that will allow a single port to be used for Level 1, 2, and fast charging. This is called the J1772-combo connector.

While this sounds nice to have a widely supported standard, there are currently no vehicles and no charging stations that support the SAE fast charge standard. The Chevy Spark EV, expected in 2013, should be the first vehicle on the market to use the J1772-combo connector.

CHAdeMO was the first to market and is the solution that the West Coast Electric Highway in Oregon and Washington is using. These stations will charge a Nissan LEAF from empty to 80% full in 25 to 30 minutes. This means that a 10-minute stop can get you as much 30 miles of added range. (The fast charger in Woodburn, Oregon makes for an easy trip between Portland and Salem.)

To further complicate the fast charging story, Tesla Motors didn't use either of the two methods we've discussed. Instead they created their own, the Tesla Super Charger.

Now that you know the various types of charging, how do you find them?

Finding Charging Stations

Recargo app

The Recargo app shows EV charging locations.

Many of the new EVs have navigation systems that display charging station locations. This is a convenient feature, since it is always available in your car—but EV infrastructure is being installed at a rapid pace and these built-in systems are often out-of-date. Also, they do not provide you with real-time operational status or availability information. For this, you'll need a smartphone.

The two most popular charging station apps are Recargo and PlugShare. Both of these apps aggregate information from the charging station providers with user-provided content. The status information can tell you if the station is operational and available. Users can check-in at stations and provide status and location notes. These notes can be very helpful. While an address can get you to the area, a note can tell you that the charging stations at Lloyd Center, for example, are on the second floor of the Northwest lot at Pole J12. Check-in reports can also tell you if the station has been recently used, and if the last EV driver to use it had any problems.

The Recargo app also includes a stream of the latest stories from PluginCars.com. (Full disclosure: PluginCars.com is owned by Recargo.)

Charging Network Membership

Charging network membership cards

EV charging network membership cards.

Many of the public charging station networks require a membership card to activate the charging session. Some of the networks charge you a dollar or two an hour to charge, but even a free station may require a membership card to start the session. You can use the apps mentioned above to find out which networks are in your area. These are the leading networks (at least in my neck of the woods):

  • ChargePoint - The largest networks in North America.
  • Blink - Funded by The EV Project. These are prolific in the Northwest U.S.
  • AeroVironment - Selected for the West Coast Electric Highway in Oregon and Washington.

Planning

For most EV driving, you'll have more than enough range for daily needs. For trips beyond the range of your vehicle, you should plan ahead. Google maps or similar tools can give you accurate distance estimates. Recargo and PlugShare can show you the charging stations available on the various route options.

If you need charging and there is no EV infrastructure available, campgrounds are one source for emergency charging. Campsites often have 120V and 240V service. If you have a portable Level 2 unit and plug adapters, this can get you back on the road in an hour or two. You'll likely have to pay the typical fees to use the campground.

As with any vehicle, occasionally, things go wrong. Make sure you have a backup plan, such as the locations of more than one station along your route.

In the extremely unlikely situation of running out of juice—which should never happen if you’ve planned ahead—it’s a good idea to have your cell phone and the phone number of roadside assistance. AAA now offers EV services, including roadside charging. If you come up just a mile or two short of your next charging spot, this could prove very helpful. But again, with a basic understanding of your vehicle’s range, the types of charging, and a few minutes of planning, your zero-emission journeys will always be smooth sailing.

Comments

· Andrew Levitt (not verified) · 1 year ago

I would add that Level 2 goes up to 19.2 kW, a level that is supported by existing AC Propulsion vehicles like the eBox (12kW for the MINI E) and likely also by the 2013 Smart ED. Dryer outlets are usually no more than 6.6kW and range outlets 12kW, so higher-power Level 2 stations are a little different.

· · 1 year ago

@Patrick Connor:

Thanks for writing the article. I've read on "Inside EV's" that there is a move to combine Level II and Level III and call the resultant "LEVEL II". How does this Jibe with what you've seen?

Also, there was no mention here about the DIN 3 phase standard which must be pretty popular in europe, as the GE Durastation, whilest solely single phase in North America, is most likely 16 or 32 A 400 volts (3 phase) in Europe. Supposedly started by VW and Diamler.
I've been having trouble finding the exact designation... Any light you can shed on this? Thanks in Advance.

· · 1 year ago

I believe the highest power level II station current is the Clipper Creek (Canadians will recognize it as Sun Highway) 75 amp j1772 unit. Either Tesla model could utilize this unit, with adapters. 70 on the roadster, 75 on the model S with $1500 dual charger option. Tesla Roadster requires $750 J1772 adapter.

· George B (not verified) · 1 year ago

Great article, Patrick! Any chance that you would include Brad Gibson's instructional video on how to use CHAdeMO DC quick charger? The breakdowns we see are often due to incorrect handling or user error, and it would be great to get this information out there: http://www.youtube.com/watch?v=317VrBDkBjg

· · 1 year ago

Andrew, you are absolutely correct. There are EVs that can charge faster than 6.6kW. This was intended as introductory, not exhaustive. I don’t know of any volume production EVs that are greater than 6.6kW at Level 2 AC. I will watch the 2013 Smart ED closely.

· · 1 year ago

Bill, the SAE has Levels defined for AC and for DC. The J1772-combo adds DC Level 1 (40kW) and DC Level 2 (100 kW) support. My understanding is that VW and Daimler have dropped their own effort in support of the SAE standards efforts.

· · 1 year ago

George, that is a great video. I have made one like it previously too. I like his better. It is to late for this article, but I hope people find it here in the comments. I will also share the link to the video on the OEVA.org facebook and twitter feeds. Thanks for sharing it.

· Anonymous (not verified) · 1 year ago

I like the Charge-A-Lot network in middle tennessee it is free no cards no hassel they even have roadside help the owner says they will be installing dc L3 shortly and will cost 2.50 per 10 min.and still no cards all will be acessable with cash or credit card.

· · 1 year ago

"I don’t know of any volume production EVs that are greater than 6.6kW at Level 2 AC."

What about Tesla model S? They come standard with 10kW, upgradeable to 20kW. As of 11/30/12, they have sold more Model S's (estimated) than all 6.6kW-equiped EVs combined.

· William Howland (not verified) · 1 year ago

@Patrick Connor

Ok, there must be something else since there are so many 3 phase chargers in europe (just by looking at the catalogue information), so I'll try elsewhere to find info. Thanks.

SAE is only single phase, unless they are coming out with something I haven't heard of yet. I'm aware of that ungainly combo thingy.

· · 1 year ago

". . . volume production EVs that are greater than 6.6kW at Level 2 AC . . .
ahem
Tesla Model S
(they are currently producing over 200 cars/week will be producing 400 cars/week by the end of this month. This is pretty close to the highest volume production of any EV - ever)
Besides, there's no sense in poorly educating the public just because the stupid OEMs want to ensure that EVs remain secondary vehicles for as long as possible by providing the slowest charging speeds possible.
If people don't know what is possible, they can't demand better.
Going even further; would you have preferred that we EV supporters, up until 2008, had said there is no such thing as an EV or an EV charger because nobody was mass producing EVs at the time?

· · 1 year ago

I stand corrected on the Model S. In my article one year ago, I listed it an the most important car (EV or other) to watch in 2012 (http://www.plugincars.com/10-new-electric-cars-coming-2012-111135.html). But this story was an intro to public charging. Because of the way that the DOE incentives were structured, most public infrastructure is Level 2 AC 6.6kW.

Yes, your Tesla Model S will charge faster at Tesla provided stations and in your garage (if capable), but that is not the focus of this public infrastructure story.

· · 1 year ago

@ex-EV1 I agree with your point about advocating for better infrastructure. However, with this article I was trying to let new drivers know what is out there today. They need this to be able to get from A to B in their new EV. As you know, many people fall in love with EVs after driving them and they become advocates. That only happens if they have a positive driving experience. And that is about having realistic expectations based on what is in-place today.

Many of the people reading and commenting on this are EV experts, but what about the person does not have an EE degree and just bought their first plug-in this week? I was trying to keep it introductory. In fact, I think there are places like the DC fast charge section where I could have kept it simpler by ignoring everything other than CHAdeMO. So where do you draw the line on the spectrum between simple and complete, there are a lot of options.

· · 1 year ago

All of the public infrastructure around here is 7.68kW (240V / 32A). The Level II standard goes all the way up to 19.2kW (240V / 80A). Just because the car is limited to 6.6kW does not mean that the infrastructure is. Plus, you specifically said "production cars over 6.6kW", not "public infrastructure over 6.6kW".

· · 1 year ago

This is probably putting too fine a point on it, but everyone seems to be saying the first standard over 3.3 kw is 6.6 kw. I would think most homes would be installing 30 amp 240 volt chargers since they're the most popular. I charge at 7.2 kw on mine.

Public things (vast majority are Nissan dealerships around here and since at a 120Y/208 dealership the Aerovironments are 30 amps and usually at least 200 volts - the lowest Ive seen so far at a Nissan dealership was 193 while charging at 30 amps, 198 before charging began, - but that was on a hot summer day.. ) are usually 208 no load at best. But my Tesla charges at around 6.0 kw to 6.3 kw on a good day there.

So is the 6.6 KW you guys are talking about really a 27 amp limitation? If so is it even much less at a Nissan Dealership (like 5.5 kw really?)

· · 1 year ago

@Bill,
I think that you are putting too fine a point on it.
5.5 to 7.2 is about the same thing at this point in the game for folks.
It does make a difference though for charging on the road. When driving a Tesla Roadster from LA to SF via the US 101 corridor, those in the know charge at Goleta and Atascadero instead of San Luis Obispo and Santa Maria because we know that the former offer 240v/70a while the latter only offer 208v/70a. This saves you up to 1/2 hour on your trip.
Again, this is way too much sophistication for most at this point though.

· · 1 year ago

@ex-ev1driver

Well, maybe I flapped my gums a bit too much. The suscinct question is, do these alledged "6.6kw" cars (fiat 500e, 2013 leaf, ffev, bmw "I things") charge at 30 amps or 27 1/2 amps? I know the Fisker is, and the Chevy Spark is going to be 3.3 kw (13 3/4 amps), so apparently DELCO built a zillion of these things for Volt, Ampera and Converj and now they have to use them up! Unless they have an agreement to use this as a "Glacial Standard" so that the Leviton 16 amp, voltec 15 amp, and pass&seymore leGrande 16 amp things still have a good reason to be sold. From a business case I guess it does make sense. Almost anyone can run 12/2 romex and find 13 3/4 amps spare in the fuse box.

· Anonymous (not verified) · 1 year ago

ok quik lesson 6.6kw@208=31.78amps -6.6@230=28.69amps -6.6kw@240=27.5amps and the leaf charger is rated at 4.8KVA@240v ok!!

· · 1 year ago

@Anonymous

You mean to say all this talk about the thing being 3.3 kw in the 2011-12 and 6.6 kw in the 2013 is totally wrong? WHERE did the 4.8 kva come from? Is that for the 2011 or the 2013? (All your numbers assume unity power factor, which would be close with an OBC).

· · 1 year ago

@Patrick Connor:

That PLUGSHARE.COM you mentioned seems to be giving out inaccurate information. For instance It showed the West Amherst Home Depot as have a J1772 and when they looked it up at the store it pointed to their outside Pad Transformer (there was coincidentally a 110 volt outlet mounted on the store itself, but it wasn't meant to be used by customers.

When I got home and looked again, it pointed to the Electrical Aisle INSIDE the store. They might object to you driving your Smart4two EV in between the aisles to look for it.

· · 1 year ago

@Bill Howland,
plugshare.com is a crowd sourced site. All of the information comes from users. There is no quality check or verification. It is only the word of the other guy, whomever that may be.
Recargo.com does a little checking and Carstations.com does a lot of checking so If you want quantity, go to Plugshare.com. If you want reliability, go to carstations.com, and if you're ok somewhere in the middle go to recargo.com.
I often go to all 3.

· Anonymous (not verified) · 1 year ago

@bill howland the 4.8kva is right out of my leaf manual look under charging then look specs this is for 2011 leaf

· · 1 year ago

@Annonymous

Ok, I'll have to ask why does everyone and his brother say its 3.3 kw and that would make sense since they claim 7 1/2 hours to recharge at 240.

· Anonymous (not verified) · 1 year ago

dont know its been round for a time now some where when nissan told the world about the leaf some said 16 amp charging at 208 ,you get 3.3kw! my leaf will charge from -0- to full in 4 hrs but our voltage is 251 where we live. its probaly best if we leave this alone we would not want to upset the status quo! and who really cares ive been doing this for 35 years and have rarely seen the exact same voltage at any location there are always differances so lets just keep there standard numbers as a general rule of thumb!!!

· · 1 year ago

@anonymous:

They never state precisely, but the ratings are a bit convoluted. Why manufacturers just can't precisely state the information I would assume is just Arrogance on the Engineers part. They never fully explain the situation to Marketing and then the info gets so jumbled by the time it gets to us consumers that its pretty bad.

Example. I had to make a few phone calls to find out the "chevy charge cord" is either 8 or 12 amps, and it doesn't matter what the voltage is. I didn't find out the 240 volt rate until I measured it myself (just under 14). Unbelievably, supposedly no one At GM knew.

So I've always worked from the assumption the a 3.3 kw car was around 14 at 240

But its also 13 3/4 at 200 so thats 2.75 kw if u happen to have 200.

So the really DUMB thing is when they give you the Wattage Rating, it is really a CURRENT rating , and anything less than 240 will give you proportionally less. Super dumb way of describing it, that is if they ever did decide to describe it.

Now, Tesla is doing the Extra Dumb thing of marketing their junk at 250 volts, as if the typical house is going to have 250 volts AT THE CAR while drawing 80 amps. Yes there will be some car somewhere that will do that.. But there will be far more Teslas driving 400 miles on a charge than the former.

· · 1 year ago

There is a difference in kVa & kW. In alternating current kVA is the "apparent power". kW is the actual, or real power the car gets. kW is the actual amount of power capable of doing work, while only a fraction of the kVA is available to do work.

In direct current kVa and kW are equal because the voltage and current and not out of phase.

· · 1 year ago

@Tom Moloughney

In practice not much of a difference, at least as far as this blog is concerned. If you were talking about light dimmers, slow speed (relative to the frequency) induction motors, single bulb arc discharge (sodium vapor, or fluorescent) magnetic ballast, cfl's, or old 1/2 wave AC motor drives, or arc welders then I'd agree. But European Standards have required KW > (KVA * .98) for so long that the On Board Chargers used in all cars that I'm aware of also meet that standard.

No one has answered my basic question... What is the current draw for basic vehicles rated at 6.6 kw (besides the GM and Tesla, the only cars i'm intimately familiar with cuz I own 'em and I've measured 'em, ) (I'll believe what the brouchure says for the S). No one has taken an Amprobe (clamp on ammeter) to measure what the current draw was on the Bmw,. Nissan Leaf, FFEV, Smart EV, etc? Also, I haven't seen definitively if the 2013 USA leaf is going to be 3.3 kw standard, 6.6 optional or if the 6.6 kw is going to be standard, and if it draws 27.5 or 30 amps?

I know the RAV4EV is 12 amps at 110, (as is the Nissan), and 200-240 is 40 if available.

· · 1 year ago

@Tom Moloughney

Your definitions only apply to Linear loads. Even Dc sources can be a victim of low apparent power factors ( a choke and a capacitor is an admitted easy power factor correction) , if the load drinks its power in gulps, even if the gulps are all direct current.

Example. If I have a load that drinks power in a 25 % duty cycle at 20 amps, it will cause much more supply wire heating than a linear load drawing 100% duty cycle at 5 amps. The total number of electrons flowing per unit time will be the same, but the 25 % duty cycle load will cause the supply wires to get hotter since their ohmic dissipation is proportional to the current squared. And if the wire size is border line than the heating is MORE than even that because the wire's resistance will go up as it heats.

· Chris A. (not verified) · 1 year ago

@Bill

The maximum amperage draw for a car with a 6.6 kW charger will be typically right around 30 amps on a standard 240v circuit. This is because the 6.6 kW rating is the maximum "output" of the charger to the battery, not from the wall and inefficiencies will bump it up to a maximum of 30 amps from the 240v circuit.

On a 208v circuit, this could go as high as 35 amps, however this is completely dependent of the battery charger capabilities. If the 2011 Leaf is an indication, the current will go higher if the voltage is lower than 240v to maintain the 3.3 kW output to the battery.

· · 1 year ago

@Chris A

So if I understand you correctly, you are saying that the so called Nissan Leaf with
So called " 6.6 Kw" on board charger, will draw 35 amps @ 208 volts?
Is this is what you've actually measured? Or on what basis do u state this? With your example 2011 Leaf ( supposedly 3.3 kw charger ), what has been the current draw to the EVSE unit while the car is charging, at either 240 or 208, your pick?

· · 1 year ago

I can only speak for myself, I haven't measured it since I dont have 'access' at public spaces, but my VOLT takes about 16 % longer to charge at a public 208 volt station than at home at around 240 volts.

· Chris A. (not verified) · 1 year ago

@Bill

Since no 2013 Nissan Leaf exists yet, my theory is based on the 2011 model (3.3 kW charger output). The 2011 will draw about 14-15 amps on a 240v circuit, 16-17 amps on a 208v circuit.

· · 1 year ago

@Chris A.

Ok, so you are saying precisely that you have MEASURED 16-17 amps when running a 2011 leaf on a 208 volt circuit?

The "3.3 kw" unit in my volt does not behave that way when on 208. It draws a bit under 14 amps at 240, and takes about 16 % longer to charge the car on 208. I'm making the assumption the current stays the same. On the hottest day of the year, the juice to my house drops to 218 with nothing on in the house, probably about 215 with typical loading. That day (next August), I'll measure the current consumption of my Volt. I have 30 amps available from my EVSE.

· Chris A. (not verified) · 1 year ago

Yes.

· · 1 year ago

@Chris A.

Ok this is quite interesting.. During the summer time a local Nissan dealer has parking lot aerovironment chargers (30 amp capability) that i've tried with my Tesla at 30 amps / 193 volts, 198 volts no load...

I'm assuming a Nissan Leaf would draw around 17 amps at 195 volts, if the charger can maintain unity powerfactor and 3300 watts... Of course if the manual says its 4800 va then 4800/195 would be almost 25 amps....And the power factor wouldn't meet Euro Standards.. Hummmm, it would be handy if I knew someone with a Leaf to experiment what happens under various conditions.

If anyone is interested, my Tesla Roadster using the supplied 110 cord will accuse you of using an extension cord if the voltage drops under 105 volts. It will allow you to keep charging at the 12 amp rate provide you can keep the juice > 100 volts. It doesn't care about 'hot- neutral ' polarity or whether it has a ground or not. Charging is at 12 or 15 amp rate, depending on what you've selected.

The volt can handle a greater dip in voltage, into the 90's. But hot-neut polarity must be right and it must have a good ground connection, otherwise it will refuse to charge. Charging is at 8 or 12 amps on the 120 volt models. (I believe 6 or 10 on the Holden volts @ 240)

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