Battery-Electric Vehicle Charging: History And Future

FEB 2 2019 BY DAVID ROPER 25

Let’s take a look at the current public fast-charging situation in the U.S.

The replacement of fossil-fuel vehicles by electric vehicles as soon as possible is necessary because of global warming due to carbon emissions from fossil-fuels combustion and the finiteness of fossil fuels. In this document, only full-electric light vehicles (BEV), cars and pickups, are considered. In order for fossil-fuel light vehicles to be replaced by BEVs there must be a massive fast-charging (50-kW to 350-kW DC power) network across a country to allow long-distance BEV driving. I shall consider only the U.S. in this document.

Charging power (kilowatts or kW) determines how fast a battery is charged (kWh battery energy = kW x hours charging).

It is important for BEV drivers to know that fast-charging kW power is not constant after a BEV is plugged in. For example, here is a charging curve for the TeslaModel3LongRange BEV (TM3LR) charging at a Tesla Supercharger from near empty to full (100% SOC), an unlikely and undesirable occurrence:

Note that it takes about the same time to charge from near empty to 75% SOC as to charge from 75% to 100%! So, trips are faster when charging more often than charging to 100%. (Tesla BEVs take this into account when their screen shows how long to charge at a specific Supercharger.)

If such a battery is charged from greater than near empty the power peak will be less than maximum; e.g., for the TM3LR charging at a Supercharger the peak when charging from 20% full is about 90-kW instead of 120kW. Also, it is important to know that lithium-ion battery capacity is less degraded over time if those batteries are not regularly charged to full capacity or discharged to near empty.

There are three different fastcharging protocols in the U.S.: Tesla, CCS for U.S. and European BEVs and CHAdeMO for Asian BEVs. The latter two are standards for non-Tesla fast-charging stations in the U.S., with CCS as the favorite.

It should be emphasized that home charging of BEVs at 240-volts AC is a very important prerequisite for replacing fossil-fuel cars by BEVs. However, most apartment dwellers will need a fast-charging network with stations everywhere, including in cities as Tesla is implementing, for charging their BEVs.

Currently the U.S. fast-charging network is inadequate for some long-distance routes but is advancing quickly, especially for the TeslaSupercharger network. There are several different fast-charging networks in the U.S.:

Here is a map of the current and planned

As shown below the Tesla fast-charging network is far ahead of other fast-charging networks in the U.S. Tesla has plans to increase the power of Superchargers to 200250kW. Greatly adding Tesla BEVs long-distance travel are the Tesla Destination Chargers (up to 19kW power) freely given by Tesla to hotels, restaurants, businesses, parks, multi-family residences and work-places. There are about 3000 Tesla Destination Chargers in the U.S. Here is a map of their locations:

Tesla BEVs make it very easy for Tesla drivers to find nearby Superchargers, even showing how many stalls are available, and Destination Chargers on the screen in the car.

  • Electrify America, a subsidiary of Volkswagen, is planning 484 locations in the U.S. for DC fast-charging stations within the next ten years:

 

In October 2018 thirty ElectrifyAmericafast-charging locations were in operation:

For example, the ElectrifyAmerica fastcharging station at exit 156 on I81 in Virginia has 4 CCS stations and 1 CHAdeMO station each with 150-kW maximum power. This is typical of Electrify America fast-charging stations in that the number of CCS stations is about four times the number of CHAdeMO stations. Electrify America has a long way to go to get anywhere near the Tesla-network capability.

The numbers add to 167 locations for fast-charging stations. The number of stalls at each location may vary and many of the stalls are lower than 50-kW power.

  • Greenlots may be the next largest fast-charging network in the U.S. Here is a map of the Greenlots station locations that are 50-kW or higher:

The green circles indicate stations that were available for charging when the map was made. The number of stalls at each location may vary.

  • EVgo is another fast-charging network. Here is a map of the EVgo fast-charging station locations:

The numbers add to 741 locations for fast-charging stations. The number of stalls at each location may vary and many of the stalls are lower than 50-kW power.

Future Fast-Charging Networks

It is clear that legacy and startup BEV companies need to forge a deal with Tesla to allow their BEVs to charge at Tesla Superchargers and Destination Chargers in exchange for helping to pay for current infrastructure, maintenance and constructing more of the Tesla Superchargers and Destination Chargers. The smaller charging networks would then need to coordinate with Tesla to minimize redundancy and create a more even density of fast-charging stations across the country.

Tesla has exchanged the standard Tesla charging port for a CCS port for Model 3s sold in Europe:

Tesla has started adding CCS cables to Superchargers in Europe along with the standard Tesla cable:

Note the Tesla cable at the top and the CCS cable at the bottom. Tesla has joined the SAE CCS association, indicating that they will be using CCS charging for future Tesla BEVs.

The logical next move for Tesla is to provide a CCS-Tesla adaptor so that current Tesla BEVs can use all of the fast-charging networks in the U.S. If a deal can be struck with legacy and other BEV startups to use the Superchargers, then Tesla could equip the Superchargers in the U.S. with an additional CCS cable as is happening in Europe. Tesla sells an expensive CHAdeMOTesla adapter for Model S and Model X BEVs, but currently not for the Model 3. Perhaps a Tesla-CCS adaptor could be made available to non-Tesla BEVs so that they could use the thousands of Tesla Destination Chargers. (One already exists.)

References

L.  David Roper, roperld@vt.edu, http://www.roperld.com/personal/roperldavid.htm

Categories: Charging, EV Education, Tesla

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25 Comments on "Battery-Electric Vehicle Charging: History And Future"

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It is good that people are paying attention to DCFC, but keep in mind the map is rapidly changing. EA already has over 92 sites and over 400 stations/dispensers. Have to look beyond the current numbers and a lot of the developments, economics, and politics are often hidden from us. It is interesting to note that EVgo has more locations than Tesla and yet the EVgo network does not allow unrestricted movement across the lower 48 states because the stations were clustered in dense urban areas to increase their utilization. There is a universal consensus though, we need more charging options.

You should then post the graph for the Audi E-Tron also. That one keeps the 150 kW peak and goes even above until 80%. Then It still reaches 100% soc at a 50 kW rate. That is almost double the average speed of Tesla Model 3 and really impressive.
The Taycan will bring a hole new dimension for fast charging though.
To be clear, I am no fan of the E-Tron and I would only buy a SUV if there were no other cars left on the planet.

https://i.postimg.cc/KjfD40K3/Audi-e-tron-charging-session-e1545161934275.jpg

That is impressive. Time will tell if their battery chemistry and Battery Management System (BMS) will manage degradation. It will be interesting if they limit how often this can be done or times in a day like on a roadtrip. Everything evolves so perhaps they found the right combo.

Afaik, all manufacturers, including Audi, are offering a minimum of 100.000 miles/ 8 years battery warranty for 70% capacity. I think it is all about cooling. Keeping the high temperatures under control at cell level seems to be the key.

I think that is his point. The charge is great, but is that only when you are starting your trip or is that after you have done a long run and then start charging up right away. The the charging curve holds it will make long trip a lot easier, if however after the batteries warm up after a long run does the recharge curve change for the worse?

Even with the faster charging you go quicker in the model3 over a long distance because the E-tron has poor range per kWh
And it is quite possible the model3 can charge a lot faster than it does. We will find out when V3 super charger comes along

It wouldn’t hurt to give someone else a compliment other than Tesla and to acknowledge that the E-tron charging cycle is incredible and worthy of praise.

There are also other resources for looking at charging infrastructure. Below is a resource that gets updated about every 6 months but is very good at showing an overview of what is installed. It has various filters the link below will show CCS.

https://www.nrcan.gc.ca/energy/transportation/personal/20487#/find/nearest?fuel=ELEC&ev_levels=dc_fast&ev_connectors=NEMA1450&ev_connectors=NEMA515&ev_connectors=NEMA520&ev_connectors=J1772&ev_connectors=J1772COMBO

“It is clear that legacy and startup BEV companies need to forge a deal with Tesla to allow their BEVs to charge at Tesla Superchargers…”

It’s not clear to me. But I know that, for example, Electrify America has already 3 times more stations than the October number given in this article. And a lot more are in construction.

Also from Electrify America ‘s site :

“Electrify America is investing in roughly 900 charging stations across the United States by mid-2019. These stations have multiple dispensers with more than 5,000 charging ports available.”

I don’t know (don’t think ?) they will be in time but it’s really far away from the claim in the article that “Electrify America… is planning 484 locations in the U.S. for DC fast-charging stations within the next ten years”.

Yes, this is becoming a myth: “Tesla has the advantage of a huge charging network”.
By the end of this year, VW with their EA and Ionity will have around 900 fast charging stations in the US and Europe.
That is almost on par with what Tesla has but with much higher charging speeds.
Let’s not forget the other companies building fast CCS chaging stations like EvGo, ChargePoint, Blink, Fastned, Shell and many others.

The 900 number with 5,000 charging ports by mid-2019 is counting L2 community charging at workplaces and residential complexes.

The number of DC locations is 484 under Cycle 1 which ends in mid-2019 but they are aiming to complete all of those by the end of 2019 (not within 10 years as stated in the article). About 300 are highway sites with 4 to 10 charging spaces. Of the highway charging spaces at each site, 2 are 350 kW CCS and the rest are 150 kW CCS although one of the 150 kW CCS spaces will also have a CHAdeMO cable. CHAdeMO is labeled as 50 kW today but will be software updated to 100 kW later. The remaining 184 out of 484 are community DC sites intended mostly for local charging in 17 metro areas with 3 to 6 charging spaces (many will be 150 kW).

Cycle 2 (of 4) starts in July 2019 and will bring a whole new set of charging plans.

Precisely Jeff. Hats off to the most knowledgeable (IMO) news man on Electrify America’s plans and progress! For those of you who aren’t aware, Jeff has a new website that will keep you up to date with all things Electrify America and more!! Check it out:
https://electricrevs.com/

Voltacharging is another service provider with a fairly decent nationwide presence. They partner with malls and retail outlets to provide free EV charging. http://voltacharging.com/map

The article links to a PlugShare page for an Electrify America site in Virginia. The article says the site has:
“4 CCS stations and 1 CHAdeMO station each with 150-kW maximum power.”

Actually, photos visible at the PlugShare page clearly show that there are some 350 kW charging spaces.

As is typical for Electrify America, there are two 350 kW CCS spaces and two 150 kW CCS spaces (one of which also has a 50 kW CHAdeMO cable).

My prediction is that relatively low speed DCFC in the 25-50 kw range will become ubiquitous at places we spend time like grocery stores and movie theaters.
Relatively high speed DCFC in the 200-300kw range will be along major interstates and highways along with Megachargers, 1-10 MW for Semis and other large trucks.

In my mind, the current Tesla Superchargers occupy an unhappy medium of to much for frequent charging but not enough for long distance travel, but the updated ones should be fine.

There’s really no reason to waste time on a commercial slow charger if your car can charge at 250kW or more. That’s like saying movie theaters and grocery stores should have a gasoline topoff service for their customers. What’s the point when you can just stop at the next corner and fill up your tank in 5 minutes. Once really high speed DCFC technology becomes supported by most EVs, central station charging, akin to current gas stations, will be the norm.

However, residential slow charging (<15 kW) still makes sense for those who can accommodate it easily (suburban or rural single family homes) since it is most likely to cost less per kWh, especially with home PV, and has a tremendous convenience factor.

It will take a while for a $25k car to be able to charge at 250kW though. But I agree, that thepattern of charging can change significnatly in the future.

I think home charging will kill the corner station. Since most will home charge most of the time, there will not be enough traffic at a convenience store to justify the expense of high speed DCFC. That kind of expense will only be justified on the highways.
Apartment dwellers will make low speed DCFC worthwhile for places like Wal-Mart, grocery stores, and big box stores as it will allow them to monitize parking spots that otherwise are dead space income wise.

I can think of at least 3 reasons that ultra fast charging is a bad idea for day to day public charging. First is that charging at such power on a regular basis is damaging to batteries. They will deteriorate faster under such charging loads. Second is both infrastrcture and usage demand costs to charge at that rate is outreageous. The third is a bit more subtle. Charging up until now is generally not an intensional act outside of long range travel. Ones does not travel and park to charge. Charging is incidental to another activity. More ubiqutous and lower power charging while parked can continue to serve this purpose. Will’s suggestion of lower power DCFC where folks tend to congregate is a better match than trying to emulate the gas station model.

ga2500ev

A good and well researched article, thank you.

Why in american those Tesla cars don’t get the same treatment as Europe with CCS?

From the article: “Electrify America, a subsidiary of Volkswagen, is planning 484 locations in the U.S. for DC fast-charging stations within the next ten years: [map]”

The map shown is their plan for Phase 1, which completes in June. There will then be three more phases over the remaining 7.5 years, each with the same amount to spend as Phase 1.

What VW need to do is build EV’s that are efficient and then they wouldn’t need to build so many super expensive fast chargers.
They have got it wrong

It might be an interesting academic exercise to compare the nationwide footprints of different networks, but on a much more practical, day-to-day level, what matters is what charging is around on the day of your specific trip, meaning set the filters on PlugShare and review it first. As long as a site has my connector, I don’t really care what the network is, I have cards for everything.

I don’t quite understand the obsession to break down the charging networks by provider other than making Tesla look good. To me there is Tesla vs. ChaDeMo vs. CCS, and you have many options of interoperability. In Europe Tesla is selling their Model 3 with a CCS Plug, since the Tesla network is really falling behind both in numbers and technology. In the US Tesla has an impressive network, but it will be tough to compete with the infrastructure provided by multiple other vendors, utilities, and cities in the long term.