Dynamic power distribution for charging up to four electric cars simultaneously

A non-Tesla SuperCharger-like network is now possible – will it be built?

Implementing a proper road trip with an electric car “simply” requires ultra-fast charging above the 100 kiloWatts charging rate.  Tesla Motors Supercharger system has proved this , with the 120 kiloWatt charging rate giving Model S owners a 1 hour (or less) recharge time for up to 265 miles of range.  While that’s not quite as fast as the gasoline cars, it’s fast enough that Model S owners have been easily making long road trips using the Supercharger network.

Earlier today we reported on a CHAdeMO and Combo Charging System compliant DC fast charging (and AC fast charging) station that could also support the same level of road trip capability, given EV’s capable of accepting 100 kW fast charging.   And we reported that the Kia Soul EV is apparently capable of 100 kW fast charging through CHAdeMO.  It’s then in our foreseeable future to have SuperCharger-like capabilities with cars manufactured by companies other than Tesla Motors.

EVTEC Expresso & Charge DC Fast Charging stationThe EVTEC Expresso & Charge station can be configured to support four charging ports, dynamically adjusting power levels at each port depending on the number of connected cars, and support up to 120 kiloWatts of DC charging power and another 60 kiloWatts of AC charging power.  While the Tesla Supercharger system has been doing this since its launch in 2012, the standards compliant charging stations didn’t have these capabilities.  Instead they fell short on both maximum system power, and on power sharing between charging cords.

In other words these facts show us that in the not-too-distant future the standards-compliant charging universe will have two capabilities not available today:

  1. Charging station makers delivering SuperCharger-like DC fast charging stations
  2. Automakers delivering electric cars that can charge at SuperCharger-like rates

Because both halves of this picture will occur through standards-compliant fast charging protocols (Combo Charging System, CHAdeMO, and three phase AC), charging network operators will be able to implement a standards-compliant SuperCharger-like charging network.

dc-quic-chargers-620b_0What do I mean by “standards-compliant”?  Consider what the gasoline car market would be like if every automaker used a different gasoline nozzle, and/or a different gasoline formulation.  Car owners would have to find gas stations supplying compatible gasoline through a compatible nozzle.  That didn’t happen in the gasoline world because the powers-that-be agreed on a standard nozzle shape, and standard gasoline formulations.  The electric car world has approximately four fast charging systems:

  • Tesla’s SuperCharger (proprietary to Tesla – their open patents policy may help other automakers adopt SuperCharger)
  • CHAdeMO (supported by Nissan, Mitsubishi, Kia, and a couple other companies)
  • Combo Charging System (supported by GM, BMW and VW)
  • Three phase AC (supported by Smart and Renault)

It’s the last three which are “standards compliant” because the implementation is controlled by independent “standards” organizations.  As cool as Tesla SuperCharger is, it’s controlled by Tesla with only Tesla’s cars (currently) capable of accessing the system.  Even though the standards compliant charging world is split between three (at least) charging standards, multi-protocol charging stations like EVTEC’s save the day for electric car drivers.  An owner of a car with standards compliant fast charging can drive up to any multi-protocol charging station and charge their car.  They can’t do that at a Tesla SuperCharger facility.


What do I mean by “SuperCharger-like”?

There’s really not much special about the SuperCharger system other than the charging rate.    With today’s news we’re seeing that the standards-compliant charging station makers are stepping up to the plate with products supporting 100 kiloWatt charging.  If EVTEC is showing one now, can ABB or Schneider or the others be far behind?

The charging station makers would be waiting for the automakers to start shipping electric cars with 100 kiloWatt charging rate capability.  Chicken meet egg, egg meet chicken …

It’s likely the gating factor for an electric car to support a 100+ kW charging rate is a battery pack large enough for a 200+ mile electric driving range.  Such a pack has to be about 60 kiloWatt-hours in size, as Tesla Motors has proven.  Why is 60 kWh an important threshold?

It’s thought that generally speaking battery pack charging should be limited to the 2C charging rate.  (“C” is technical terminology – where a 1C charge rate or discharge rate means the pack either charges or discharges fully in one hour)  At 60 kiloWatt-hours a 120 kiloWatt charging rate is 2C, a 100 kiloWatt rate is slightly less, and a 60 kiloWatt charging rate is 1C.


Nissan and GM have both announced they’ll begin selling 200 mile range electric cars with MSRP’s in the mid-$30k range beginning in 2016-17.  Tesla Motors is slated to do the same beginning in 2017.  Isn’t it likely the other automakers are close to making similar announcements?  Neither Nissan (CHAdeMO) nor GM (Combo Charging System) have predicted the sales rate, but Tesla promises to be selling a couple hundred thousand cars a year by 2020.  (ASIDE: If Tesla’s plans requires a Gigafactory, where is Nissan’s or GM’s Gigafactory?)

In less than 2 years the pressure will be on the standards-compliant charging station manufacturers to support a higher charging rate.  The amount of pressure depends on the sales rate for each fast charging protocol.

Will this pressure cause construction of a standards-compliant SuperCharger-like charging infrastructure?

Tesla’s SuperCharger system is focused on inter-city travel while the CHAdeMO/CCS world has focused on city/regional travel.  The company is rapidly building its network and offering free access for Model S (and soon Model X) owners.  By 2017 they’ll have blanketed North America, and large parts of Europe, China, Australia, and who-knows-where-else.

The standards-compliant charging world hasn’t been built with a cohesive vision like Tesla’s.  Rather than a single charging network, there are several competing network operators in each region.  Charging network location planning is also inconsistent, with no coordination to form a cohesive mesh.   If our future follows from current conditions, 100 kW standards compliant charging station deployments will be spotty at first and be split between multiple charging network operators.

A lot will hinge on the sales rate of 200+ mile range electric cars from the non-Tesla manufacturers.  The limiting factor may be battery manufacturing capacity since it’s only Tesla who is investing in large scale battery pack manufacturing capacity.  Will there be enough CHAdeMO or CCS compatible cars (the non-Tesla manufacturers) to support development of significant 100+ kiloWatt charging infrastructure?

It may be that come 2016-17 that Tesla is the only manufacturer offering a completely compelling story:  High manufacturing rate and a ubiquitous 100+ kiloWatt charging infrastructure.

The pieces will be in place for the non-Tesla electric car makers to offer their version of that story.  Multiple 200+ mile range electric car models will be on the market, perhaps still split between the CHAdeMO and CCS charging protocols.  The charging network operators will have started to deploy inter-city infrastructure capable of a 100 kiloWatt charging rate.  But will the non-Tesla (CHAdeMO/CCS) story be compelling enough to deter interest in Tesla’s offering?

About David Herron

David Herron is a writer and software engineer living in Silicon Valley. He primarily writes about electric vehicles, clean energy systems, climate change, peak oil and related issues. When not writing he indulges in software projects and is sometimes employed as a software engineer. David has written for sites like PlugInCars and TorqueNews, and worked for companies like Sun Microsystems and Yahoo.
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About David Herron

David Herron is a writer and software engineer living in Silicon Valley. He primarily writes about electric vehicles, clean energy systems, climate change, peak oil and related issues. When not writing he indulges in software projects and is sometimes employed as a software engineer. David has written for sites like PlugInCars and TorqueNews, and worked for companies like Sun Microsystems and Yahoo.

One Comment

  1. I like your post and agree with much of your analysis. That’s why I started a company to build a fast charging network that allows route travel. The company is Sunspeed Enterprises and we’re starting along the most beautiful highway in the world, California’s scenic Highway 1, what we have dubbed the Pacific Coast SunTrail route. Supporting the three fast charging standards prevalent in the US (CHAdeMO, CCS, and Tesla) is part of the plan, as is providing j1772 chargers for the plug-in hybrids of today. Sizing the electrical supply to support today’s cars and the 300+ mile ranged EVs of the future is a bit of a trick, but also part of the plan. Creating a branded network based on standards so EV drivers know what to expect is core to the concept and we hope that our competitors will up their game to match us.

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