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www.ElectrifyAtlanta.com

Electric Vehicle information for Atlanta and Georgia

DC Fast Charging technology

December 2023 note: this page started out with the information that is now at the bottom: the DCFC charging station hardware table and the DCFC performance curves. Those two sections have not been updated since 2018, but they’re fun to keep around because they illustrate the early years of DCFC deployments and performance.

Recently I have added two new sections at the top:

  • which cars have 800V drivetrains and thus can charge much faster
  • which cars and stations offer the new Plug and Charge (ISO 15118) capability

Eventually I hope to add sections for:

  • an illustration / explainer about EV charging curves, explaining how PEAK charging power isn’t as important as how long that peak is held (i.e. the “area under the curve”), featuring the excellent FastNed data set currently buried at the bottom of this page
  • which manufacturers (of cars and stations) have made announcements regarding the Tesla NACS plug and their implementation status

Generally, I’m trying to documenting some details which are hard to find out and track via regular media.

For general information about DCFC usage and EV roadtrips, please see the public charging stations and roadtrips page which was recently updated.

-Chris

Sections below:

Introduction

DC Fast Charging (DCFC) is a class of technology that can charge electric vehicles much faster, on the order of minutes rather than hours.  Widespread rollout of DCFC stations is the true game changer in the automotive market, because with DCFC stations, EVs get over the last hurdle — quick “fueling” and thus long distance travel.

See the public charging stations and roadtrips page for basic details about the three different DCFC plug standards and how the market has been slowly converging on CCS.


EVs with 800V drivetrains

Up until 2020 or so, all EVs had 400 Volt drivetrains, meaning a 400V battery, 400V motor and 400V DC Fast Charging. Then EVs started to come out with 800V technology, providing more powerful drivetrains and much faster DCFC. Any 800V car will inherently charge much faster on roadtrip stops at DCFC stations, and over time we expect to see many more such cars come to market. Much like basic 4-cylinder gas cars vs luxury 6-8-cylinder gas cars, we may see the 400V drivetrains move to the budget end of the market and 800V go to sports and luxury. (Note: the numbers “400” and “800” are of course approximate and will vary from car to car, but those are the general drivetrain class terms used in industry.)

One caveat about 800V cars is that they typically offer lower power charging capability at older DCFC stations that might only go up to 400V. At those stations, the car uses some kind of technology inside to adapt the station’s 400V output to the car’s 800V battery. Different car companies are solving this different ways, including:

  • a dedicated “DC-to-DC converter” component that changes the voltage
  • a repurposing of the motor inverter during the charging session to convert the voltage
  • a battery design that allows the car to internally break up the 800V battery into 400V halves for that 400V charging session and then charge those

Depending on how they do it, there may be some sort of power bottleneck, just like the AC charging bottleneck encountered on Level 2 . The table below references what we know about that solution for each car, and critically what the bottleneck number is. This is particularly important for anyone charging their CCS car at an older (“V3”) Tesla supercharging site, because those are only capable of 500V max and so the power you get will depend on the conversion tech used inside your car.

Makes and models with 800V drivetrainslaunch date400V charging capability
Audi etron GT / Porsche Taycan (same drivetrain)201950 kW via DC-DC converter (150 kW factory option)
GMC Hummer EV2021___ kW via battery split to 400V x 2
Hyundai Ioniq 5 + 6 / Kia EV6 + EV9 / Genesis GV60 + GV70 (all same E-GMP drivetrain)2021100 kW via motor inverter
Lucid Air202250 kW via DC-DC converter
Tesla Cybertruck2024
Audi A6 + Q6 / Porsche Macan (all same PPE drivetrain)2024___ kW via battery split to 400V x 2

EVs with Plug and Charge (ISO 15118) capability

Plug and Charge, aka P&C or ISO 15118, is a new industry standard that allows you to plug into a pay charging station and have the charging session start up automatically without you having to use a credit card or phone app or RFID card. The station basically recognizes your car, associates it with your account, and that account gets automatically debited — all within a couple seconds and via secure protocols. Tesla has had their own in-house capability since they launched their “supercharger” network in 2012, however that was a vertically integrated network with Tesla cars using Tesla stations — and wildly insecure at first. P&C is a multi-vendor effort that allows many car companies and many charging providers to interoperate via a published standard: ISO 15118. In short, it allows you to have that slick Tesla experience in your non-Tesla. Deployment of this technology (to both cars and stations) started in 2021, and it’s worth noting that Tesla itself will be running ISO 15118 on their newer stations.

Below is a list of EVs that support P&C. For more up to date information, google “‘plug and charge’ EV list” and “‘plug and charge’ car-model-here” and look through the search results — and not just the first result! The carmakers are all promising this capability, but you have to check independent sources to see A) if they have actually implemented it in the charging hardware on the car and then B) if they completed and deployed the software that implements it.

Note: this is not the “Autocharge” hack that EVgo and others are doing. That is not real ISO 15118 and is less secure.

Make and Modelfirst model year with supporting hardwaresoftware released
Audi Q4 and Q8 etron
BMW i42024, built on or after 01-Aug-2023mid 2024
BMW i5 + i72024July 2023 (iDrive 8.5)
BMW iX2024, built on or after 01-Mar-2023July 2023 (iDrive 8.5)
Ford F-150 Lightning2022?
Ford Mustang Mach-E2021?
Genesis GV70 + GV802024
Mercedes: all models
Porsche Taycan2021
Volkwagen: all ID models2023?early 2024

DC Fast Charging cabinets in service in Atlanta market

In 2014, the Atlanta market started to see a lot of DCFC sites popping up, some with just one of the above plug types, and some with two. This section serves to document the different kinds of DCFC cabinets seen in metro Atlanta.

See the bottom of the page for data on the charging rate (power) of different cars.

First generation DCFC at up to 50 kW:

picturemanuf.networkplug type(s)powerPlugshare examplenote including date first seen in Georgia
DCFC-BlinkBlink?BlinkChademo only50 kWnoneJul 2013; two plugs, power split; both Georgia units replaced
DCFC-EatonEatonmiscChademo only50 kWnoneNov 2013; can do SAE Combo but not seen in ATL yet; both Georgia units replaced
DCFC-NRGSumitomoNRGChademo only44 kWTown CenterNRG EVGO launched in Atlanta market in November 2014, although these stations were widespread, found at most Nissan dealers prior to that
Georgia-Power-branded-DCFCEfacecChargepointChademo and SAE Combo50 kWGeorgia Power HQNov 2014 testing, Jun 2015 launched
Signet-Greenlots-DCFCSignetGreenlotsChademo and SAE Combo50 kWCobb CountyApril 2015
SignetGreenlots?Chademo only50 kWNissan in GriffinApril 2015; same as above but equipped with only Chademo port
BMW-ChargeNowIES/BoschChargepointSAE Combo only24 kWBMW officeJan 2015; some only deliver 21 kW; BMW/VW partnership
IES/BoschChargepointChademo only24 kWcorporate officeJan 2018; rare Chademo-only IES/Bosch unit
BoschSAE Combo only25 kWChevy dealershipNov 2017; same IES/Bosch unit turned sideways?
NRG-BTC-DCFCBTC PowerNRGChademo and SAE Combo50 kW?AAA storesSuwaneeApril 2015; can run off 208V 3-phase power; output cable may be limited to 100 Amps, which limits peak power to about 40 kW
ABBABBNRGChademo and SAE Combo50 kWPerimeter SummitNov 2015
Tritium-VeefilTritium VeefilChargepointChademo and SAE Combo50 kWGWCC downtownNov 2015

Second generation DCFC at up to 350 kW:

picturemanuf.networkplug type(s)powerPlugshare examplenote including date first seen in Georgia
ABBElectrify AmericaChademo and SAE Combo150 kWKennesaw EA locationJul 2018; see also 350 kW stations at same location
ABBElectrify AmericaSAE Combo only350 kWKennesaw EA locationJul 2018; no cars can pull 350 kW yet, but the station is ready!
Coming soon via the EA rollout: Signet, Efacec and BTC Power

Tesla Supercharging (for Teslas only) at up to 120 kW:

picturemanuf.networkplug type(s)powerPlugshare examplenote including date first seen in Georgia
Tesla-V1Tesla v1 stations, never seen in Georgia, up to 90 kW
Tesla-V2Tesla v2Tesla owners onlyTesla cars only120-135 kWpedestals, cabinetMay 2014; much better tech than anyone else, but for Teslas only; two pedestals per 120-135 kW cabinet with power sharing algorithm; automatic authorization upon plugin, no cards needed; see links to left for lots of pictures, and more cabinet pictures
Tesla-urbanTesla urbanTesla owners onlyTesla cars only72 kWAtlanta LenoxAug 2018; “urban superchargers” offer somewhat less power than regular superchargers, but no power sharing so you get the whole 72 kW right away; the urban installs are designed for local owners to get a charge in about an hour, and are typically located at major retail.
Tesla v3 stations, rumored to launch by end of 2018, rumored up to 250 kW and possibly autonomous plug in

DCFC station attributes to consider:

– which DCFC plug standard? e.g Chademo only, or dual-standard with both Chademo and SAE Combo
– what is the peak power? 24 kw, 50 kW, 150 kw, 350 kW … HUGE difference in charge time
– for Chademo, which plug type exactly? old clunky Yazaki CHV-03 “firehose” design, or newer designs? Yazaki CHV-04, Sumitomo, JAE, see pics
– dual-standard cabinets effectively serve all three DCFC types, since Tesla can use Chademo
– is the DCFC a split design with separate cabinet and kiosk, or single unit?
– cabinet size? contrast Efacec (big) vs Signet (small)
– is it prone to overheating? do the filters clog?
– does it accept input power as 480V/277V 3-phase or 208V/120V 3-phase? service install expense vs current (amperage) needs

DCFC station technology developments that are in the pipeline:

– 150 kW peak power capability — stations being deployed as of 2018, cars arriving in late 2018
– 350 kW peak power capability — stations being deployed as of 2018, cars arriving in late 2019?
– stations that have multiple plugs that can let the second car authorize and then automatically start charging after first car finishes
– stations that have multiple plugs being able to supply power on all of them simultaneously, splitting power somehow*
– stations and cars that talk to each other when you plug in and authorize automatically*; “Plug and Charge” aka IEC 62196
– liquid cooled charging cables to allow higher power flows
– cars that can absorb 100 kW and more*; first cars expected at end of 2018
– cars that run at ~800 Volts instead of ~400 Volts, which alone could double charging power rates; Porsche claims to be doing this
– U.S. electrical code (NEC) revising the “HV threshold” from 600V to 1000V, which would allow consumer handling of 800V cabling
* Tesla already does this


BMW i3 DCFC charging power curve

This graph was generated from data gathered in early 2015 during DCFC sessions at stations with SAE Combo plugs. Most of the sessions were done at stations that deliver peak power of 50 kW; the lower curve sessions were done at a 21 kW station. The middle curves were typically sessions done at a 50 kW station that was delivering only 36-37 kW; typically this degraded power will be due to high ambient temperatures or a current limit in the station’s input or output.

The first key threshold to note in these curve is what SOC the car starts ramping down the power that it can absorb. On the i3 with the 22 kWh battery, it starts ramping down from 50 kW at around 55% SOC.

The second key threshold to note is what SOC the car is absorbing less than 6-7 kW. At that point, the car is charging as slow as it would on a regular Level 2 (J1772) station. If someone is waiting behind you to use the DCFC station, and you need to charge all the way to 100% for some reason, you should move to a Level 2 station and let the next person absorb the full capability of the DCFC station. What is interesting is that this curve shows that this “Level 2” threshold is not reached until about 93%, much higher than the 80-85% number that is often quoted as a charging etiquette guideline.


Tesla Model S DCFC charging power curve

I gathered this data in March 2015 on a long roadtrip in a Model S (thanks Keith R). There are two thresholds to note here.

First, similar to the i3 curve above, the Model S charges at max rate of 120 kW until 30-35% SOC, and then starts to ramp down. Obviously the Tesla is charging far faster than the i3 to begin with, due to the far bigger car battery and far faster charging stations, but it still exhibits similar behavior — the battery can absorb full power only when somewhat empty.

Second, at around 65% SOC the car is absorbing around 60 kW. This is notable because it’s half of the 120 kW capability of the Tesla stations. Tesla supercharging stations are unique in the industry in that each DCFC cabinet (typically hidden behind a fence) actually supplies TWO charging pedestals (the plug hardware that you actually touch). If ONE car is plugged into one of that pedestal pair, it gets all the power. If TWO cars are plugged into each of the two pedestals associated with that one cabinet, then the cabinet splits the power between the two pedestals! I don’t know exactly how this split is done (equally? first person gets more?) but I suspect this 60 kW threshold may play a role.

Atlanta Tesla owner Keith R has made these observations:
– First one there always wins. And it also doesn’t even matter after you are above 65%. You will be capped to no more than 64 kW no matter what if your charge level is above 65%.
– Each DCFC cabinet has 10 modules (or 12). The first car “reserves” as many as it wants up to 7. That provides approximately 130-140 kW (~20 kW per module) and leaves 3 modules for a car arriving in the other stall. When the first car drops below 100 kW then it releases one of the modules, and again once it drops below 80 kW draw, etc. The second car enlists those released modules if it wants them. But it never “steals” from the first car that arrives. They only become usable by the second car if the first car isn’t using them.
– Whether another car is there or not doesn’t matter after 60% charge level (typically about 15 to 20 minutes) because that’s the point where the ramp-down curve crosses 64 kW.
– In the very worst case scenario, with two cars plugging in to shared stalls at almost the same time, both with nearly empty batteries – the “loser” will only have a 50% reduction for that 20 minutes or so… or to think of it another way, it can only cost you (at a maximum) an extra 10 to 15 minutes of charging time if you happen to get there last. And no loss if you get there first.


Tesla Model 3 DCFC charging power curve

Atlanta-area Model 3 owner Matt M. gathered this data in March 2018 on a long roadtrip (thanks Matt).

As with the Model S, and as called out in the graph, you can see the thresholds where it starts ramping down from max power and where it drops below Level 2 power levels.

Compare it with the Model S graph above, and notice how it’s screaming along at the 120 kW peak power for significantly longer, starting to ramp down at 50% SOC instead of 30-35% SOC.

Note that my Model S data above is now rather dated; a new Model S may behave better than the 2014-2015 car that I gathered my data with.

Also I don’t have data for 90-100% SOC on the Model S.  It would be interesting to see if it approaches 100% SOC as gingerly as the Model 3.  I take the Model 3’s careful ramp from 90-100% SOC to mean that Tesla is really pushing their 100% threshold high on the batteries. That would fit their past behavior — they’ve always been much more aggressive on their battery thresholds than other makes.

Update: 18 months later, Tesla had refined both the Model 3 and their superchargers to offer up to 150 kW of power. Check out this detailed plot of a charging session provided by another Tesla owner.


Nissan Leaf DCFC charging power curves

A couple owners in the Atlanta area helped me gather this data for the Nissan Leaf — thanks David K and Robert K!

The lowest curve is from a 2011 Leaf, showing how the battery technology in the earliest Leafs really not as good as just two years later.  Indeed, there is quite a bit of variance in the cars from year to year.

Most of these sessions were done on NRG EVGO stations, which as you can see peak out at around 42 kW. The one curve that peaks at around 48 kW is from a session done on a Blink DCFC station.


DCFC charging power curves from FastNed

FastNed is a Netherlands-based company that has saturated their home country with DC fast charging stations, and is now expanding into other European countries. In the summer of 2018, they published charging curves for several car models, similar to the data that I gathered above. They cover many car models, including several that I don’t cover above, including the newer BMW i3 with the 33 kWh battery, the 2018 Nissan Leaf with 40 kWh battery, and the Chevy Bolt EV (via the Ampera-E badge-engineered sister). If you liked the curves I presented above, I strongly recommend checking out that article.