Dodge Circuit EV Concept at 2008 Los Angeles Auto Show
Authors note: Back in 2009 when I was still the technical editor of the now defunct GreenFuelsForecast.com, I sat down for lunch with Lou Rhodes and Doug Quigley of Chrysler. At the time, Lou was president of the company’s ENVI divison and Doug was executive engineer for EVs. Over the prior 18 months, ENVI had shown off two sets of electrified concepts and was still hoping to get at least one into production. At the time of this conversation, Chrysler was struggling to survive and barely a month later, the company would go through bankruptcy reorganization before emerging as part of Fiat. While none of the concepts at the time, made it to production, lessons from the project were fed into the Fiat 500e and in 2017 a plug-in hybrid Chrysler minivan finally arrived as the Pacifica.
(Auburn Hills, MI, March 27, 2009) Over the last two years numerous automakers including Nissan, Renault, Mitsubishi and General Motors have garnered attention for efforts to develop commercially viable electric drive vehicles. More recently Chrysler has also publicly jumped into the fray with the creation of its ENVI division, unveiling of several prototypes and the announcement that at least one of those vehicles would go into production in 2010.
Lou Rhodes, President of ENVI and Doug Quigley, Executive engineer spoke with Green Fuels Forecast about Chrysler’s plans for electrification. When ENVI was publicly announced in September 2007, many saw it as a knee-jerk reaction to all the hype that General Motors was getting for the Chevrolet Volt. In fact, the work of ENVI began quietly in late 2005 when the Chrysler Group was still firmly ensconced within DaimlerChrysler.
Around that time period engineers in Auburn Hills and designers at the since closed Pacifica design studio in California began work on what would eventually become the trio of concepts revealed at the 2008 North American International Auto Show. All three of these concepts were electrically driven with different variations of the same hardware architecture. The Dodge Zeo was a pure battery electric sports coupe, while the Jeep Renegade was an extended range electric vehicle (ER-EV) that used a diesel engine to sustain the battery after its 40 mile range was depleted. The Chrysler ecoVoyager also used the ER-EV approach but with a hydrogen fuel cell providing the extra range.
Rhodes tells GFF that the project began with the question “If we were to redefine ourselves as a company in the year 2020, what would our portfolio look like, and then what technology would we need to enable it?” According to Rhodes and Quigley, all of the work done by the ENVI team has been rooted in taking a holistic approach to answering this question in a manner that made business sense.
“At that we were still DaimlerChrysler so we leveraged the research group out of Palo Alto” says Rhodes. “They were doing customer, social, ethnographic research, social trends, technology trends.” “One of the off-shoots of that was this need for advanced propulsion.”
“We liked the California group because the guys were always challenging vehicle proportions and packaging” says Rhodes which led to the need to come up with a flexible architecture. This allowed the creation of a “D-segment car the size of a minivan inside.” Those 2008 concept cars were the direct result taking the technology and creating products that specifically fit the respective brands.
“The premise of an electric drive was set there, the modular strategy which we still have today. How do I use a common set of motors? How do I specify a common cell and module to create a pack which is unique? and then if some will be all-electric and some will be range extended, how do we use and internal combustion engine and a fuel cell for range extenders?”
Eighteen months after asking those questions, the answers were publicly displayed first as concepts and then later in 2008 as production prototypes. The ENVI team has continued to work on those prototypes with the publicly stated goal of bringing at least one to series production in 2010.
While observers at the 2008 Detroit show focused mostly on the design direction of the concepts keeping in mind Chrysler’s long history of previewing that with concepts, Rhodes points out something else. “What they missed were all the clues we were laying about what our overall internal strategy was. They all had the same family of electric motors.” All the variants also used battery packs based on a common battery module (consisting of some number of cells) configuration that could added together for different applications. The modules themselves could contain different cells based on whether the application needed more power or energy.
The concepts were built up from “aluminum structures and new architectures that allows us to do more efficient execution of the next generation of vehicles.” Rhodes acknowledges that “long-term, the end destination is all electric, but the nearer term steps is we want to be provide the battery to meet the 40 mile range but have some efficient way to extend it. We didn’t want to limit the technology, certainly IC engine, gas and diesel as range extenders made a lot of sense. Fuel cell because of our Daimler heritage, we’ll start to back away from fuel cell from a primary development but we don’t want to miss an opportunity to use that as a range extender when it becomes more viable and affordable.”
“When we showed last year the ENVI portfolio (the Dodge Circuit, Jeep Wrangler EV and Chrysler Town and Country EV), all that was still there. The E-drive system logic, the strategy was still laid out just to the next level of maturity.”
Those cars according to Quigley those three vehicles that were shown in September 2008, were not concepts but were in fact early development prototypes. The key to Chrysler’s strategy according to Rhodes is a broad based approach that uses hardware that can be applied to multiple vehicles to quickly ramp volumes and drive down costs, something his team has been working on for three and a half years.
Applying the electric drive systems to existing vehicles like the Jeep Wrangler and Patriot and the minivan was done to speed up time to market for the first generation. Quigley tells GFF “it was an enabler of the platform development. It’s too lengthy to just execute an electric platform. We’ve also been pretty clear that gen 2 is not just putting electric systems in an existing vehicle, which is why we wanted to put our first foot forward with the concepts. No these are optimized electric systems, you don’t necessarily recognize them as the architecture people are used to today and that’s a good thing.”
Rhodes explained that by doing just one car, “you can end up trying to convince yourself that somehow you’ll get everybody to compromise their basic needs and go to that car because it’s so compelling.” The problem is that taking this approach can lead to optimizing hardware for one vehicle and then having to completely re-engineer it for additional applications. This can lead to greatly increased costs and stretched development times.
The ENVI team has been evaluating the duty cycles and usage patterns of the full range of vehicles to determine the scope of what is needed. Based on this data the electric drive hardware is being developed with the intent of making it scalable to different types of vehicles. “The existing platforms were hand-picked to say it fulfills the promise, of putting batteries under the floor, of motors with front wheel drive, rear wheel drive, all wheel drive. We weren’t compromising in what we had to do,” explains Rhodes.
Because of new corporate average fuel economy (CAFE) rules every vehicle has have its energy demand reduced. Given limited resources for development in the current economy, anything that can be applied across the lineup with minimal extra work is seen as a plus. At the same time, Quigley explained that one focus of the development was to not compromise the utility or performance of the original vehicle. “We’ve kept the package and we’ve kept the performance on par with or improved from whatever the donor vehicle was.”
At the time of our discussion, Rhodes and Quigley declined to get specific about exactly which companies will supplying supplying systems for its electric vehicles. There has been speculation that A123 Systems is working with Chrysler on batteries but Rhodes said only that further announcements would be made in the next few weeks. Rhodes did however talk about battery technology in general terms. He did confirm that Chrysler is not and would not work exclusively with one single battery supplier. Given the rate at which battery technology is evolving, it would be foolish for Chrysler or any other automaker to get tied down so soon. However, since Chrysler has a stated goal of producing an electric vehicle starting in 2010, a lead battery supplier has been selected for that program.
Chrysler intends to control the form factor and specifications of the battery modules (groupings of cells) while leaving cell suppliers the flexibility to innovate. Managing the module format will allow ENVI engineers the ability to arrange them into packs as needed for different applications while maintaining common interfaces. At this stage of battery development Rhodes told GFF that the time hasn’t yet come to standardize the format of the cells. In the future as battery technology matures, this may change and its an area that is being discussed in the United States Advanced Battery Consortium (USABC) which also includes General Motors and Ford.
Chrysler will be controlling the battery management system interface to the rest of the vehicle. The intent is to continue using the existing controller area network which facilitates communications between all the various electronic systems in the vehicle. “It’s the handshake between the supplier and the rest of the vehicle integration, so that BMS has to be a close relationship with multiple suppliers. They’re going to have one end of that BMS that says for this particular cell, the thermal behavior of my cell, the discharge rates of my cell, I need to have the BMS do X. If we’re going to talk to our motor and our controls it has to do Y so there has to be a code cooperation between suppliers and Chrysler. There will be IP and algorithms and strategies that allow that.”
“At the end of the day we’re not sure if a customer is going to buy our product vs a competitor’s because of the motor, or the shell or the module or how slick all that was in 2009. They’re going to buy it because of the way we integrate it into the vehicle and the user experience” say Rhodes “so that’s the pieces we want to control”. Quigley elaborates by explaining “today we own the vehicle level controller and the pack suppliers own the BMS. We both agree looking forward that those two systems will probably become one, then the question becomes who will own that? I think at the end of the day we probably will.”
In January at the Detroit Auto Show former GM CEO Rick Wagoner announced that GM would be doing the final assembly of the battery packs for the Volt in-house using cells from LG Chem. Chrysler intends to follow a similar approach of handling final assembly and vehicle integration.
General Motors and Tesla have both focused on liquid cooled lithium ion battery packs. The Tesla pack is unique in the industry at the moment in using the same type of metal oxide chemistry used for consumer electronics batteries. These batteries have in the past experienced both thermal stability issues and limited charge cycle life. GM will be using a manganese spinel chemistry from South Korea’s LG Chem for its first generation. This chemistry can withstand many more charge cycles than metal oxide cells but for safety and durability GM is also using liquid cooling even though this adds cost, weight and complexity.
Chrysler is testing both liquid and air cooled batteries at this time and is likely to use both approaches. For a pure battery electric car like the Circuit sports car, the company is leaning toward an air-cooled pack. One of the benefits of using a liquid cooled pack according to GM is that the battery can be pre-conditioned to its optimal operating temperature while being charged. Batteries don’t produce as much power when they get very cold such as when parked outside during winter weather.
Rhodes explained that the battery only vehicle has many more cells than the RE-EV and thus produces more overall power even though the power per cell is reduced. As a result the overall output is still significantly higher and net reduction is less than what would be experienced with the smaller pack used in the extended vehicles. Nonetheless conditioning the pack during charging will still occur, there is simply less flexibility and precision with the air-cooled pack.
Similarly when energy is being drawn from the pack, the amount of the current per cell from a full EV is considerably less than from an RE-EV. The lower current draw means less of a temperature increase in the cell making air cooling a viable option. In fact the large packs being used for the full EV have a huge thermal capacity. Quigley explained that a pack was thermocoupled and tested in Arizona for one week. With desert temperatures ranging from 120 degrees during the day to near 40 degrees at night, the internal temperature of the pack never varied by more than about two degrees. In the range extended vehicles the draw on the individual cells is higher necessitating liquid cooling with a heat sink to manage temperatures.
Because the range extended vehicles have smaller packs that will cycle more often, liquid cooling and precise temperature control is more critical to ensuring durability and safety. Like the Volt, Chrysler’s vehicles will be pre-warmed while being charged and if the temperature is extremely cold, the range extender may start up even if the battery has a charge but wasn’t plugged in.
The power to energy ratio of the batteries for the range extended vehicles means that with enough energy for a 40 mile range, there will always be plenty of power. Like GM’s Voltec system and the parallel hybrids that are on the market today, the full capacity of the battery won’t be used. Instead, the battery will be charged only to about 80-85 percent of full charge and discharged to 30-35 percent. That 30-35 percent “depletion threshold” will provide some power buffer power when needed for transient conditions.
Under normal conditions, the range extender will operated at relatively constant speed (about 2,800-3,000 rpm) to maintain the battery state of charge. If extra power is needed for passing or climbing a hill, the battery charge level will temporarily dip below depletion threshold. Because the system does not know how long power will be needed, it operates this way for a time the battery reaches a minimum level and then the engine is output is increased to its maximum in order to maintain and replenish the battery.
Rhodes and Quigley are confident that the vehicles being developed will not experience any issues with performance loss during charge sustaining driving under any reasonably expected conditions. At this point they are reluctant to get into too much detail, but the specifications that have been listed for the cars shown so far do not represent the final production specification.
Rhodes tells GFF, “The range extender that we showed in the January (2009) cars was the same range extended engine for all of them. We just said for those cars we’ll use the same less than 1.0-liter engine. What we didn’t elaborate on was that those would come in naturally aspirated, supercharged and turbocharged versions so we can get the continuous output that we need for those different vehicles.”
“It will all depend on the continuous power-demand for the charge-sustaining mode in the different vehicles. It will be 35 kW in the minivan, 45 kW in the Wrangler. It will have a single operating speed for the most part. Now when you look at the turbocharger, it’s not the traditional turbocharger. It’s always operating, more like a diesel on a ship. There’s potentially no waste-gate, it’s very much optimized to provide the highest output for a specific rpm and get great efficiencies.”
“Another approach is to look at a family of range extended engines that go from sub 1.0-liter as one family, 1.0-1.4-liter as another and then maybe even our world engine as the third.”
In discussing to the Volt specifications, Rhodes feels the 1.4-liter engine being used by GM may be “over-specced as we see it for that application.” Quigley offered up another possible explanation for the difference in engine specs between the ENVI vehicles and the Volt. “We’re not privy to all their (GM’s) battery specs, nor are they to ours, what your battery total energy is and the power to energy ratio inherent to those cells is going to for a large part determine that APU (auxiliary power unit or range extender) need.”
“One theory is, ‘what if I want to spend a little bit less on my battery? go a little smaller, have a little less energy on board and round up on the APU?’ That’ll work cause the APU will then support that extra energy, but of course what’s the trade-off? Well you burn more gas. But it is going to be probably a cheaper proposition due to the current cost per kilowatt-hour.” GM hasn’t discussed details of the power output of its production intent Volt battery cells but based on this reasoning lower battery power may be the driving force behind a more powerful engine.
In terms of cost, Rhodes doesn’t see much difference in cost in batteries based on the power/energy balance. The element that will drive down cost is production volume and Chrysler is “willing to share technology, share ideas, share components because our (Chrysler’s) end goal is to make these affordable to our customers.” He sees the inflection point where costs really drop as “safely at 100,000 units” so that’s where volumes need to get to quickly to make electric vehicles cost effective from a purchase price standpoint.
Of course when discussing total cost of ownership, the electric vehicle question becomes much more complicated. While the cost of electricity from the grid varies widely, going as low as “free” if the owner has solar panels, even the highest costs are generally much lower than the cost of gasoline. When the fuel cost is combined with the purchase price, the elevated cost of an EV becomes more palatable.
On the other hand a substantial portion of the cost of an electric car resides in the battery. Given the limited lifespan of the lithium ion batteries used in consumer electronics devices and computers, many people have concerns about having to replace a car battery at a potential cost of thousands of dollars. Given the fact that current hybrid packs can cycle up to thousands of times a day and an EV pack might only go through thousands of cycles in its lifetime, Rhodes is actually more confident in the ability of EV packs to survive. “We don’t have major concerns, we have a lot of validation and a lot checks, absolutely” says Rhodes “but the premise of being able to provide a long life warranted lithium ion battery for RE-EVs and EVs we don’t see as an issue.”
Following our discussion, Rhodes took this author for a ride around the Chrysler Technical center in one of the five Dodge Circuit Prototypes currently running in the US (several others are being tested in the UK). For the Circuit which is a sports car very similar in many respects to the Tesla Roadster, Chrysler plans to offer a driver selectable range of regenerative braking going from a coast down mode that mimics engine braking up to about 0.4g of braking. The thermal management of the prototype is sufficient to withstand sustained hard driving without overheating the battery, motor or electronics.
Rhodes is confident that the Circuit could easily be raced on the track without running into overheating issues something that can’t be said for early Tesla Roadsters. After two hard laps in the Circuit, Rhodes pulled out an infrared temperature gauge and the motor, power electronics and battery pack were in the range of 65-70 degrees on a day with ambient temperatures in the mid-50s.
Given Chrysler’s precarious financial situation many observers have considered the Chrysler electric vehicle program to be little more than vaporware. The appearance of a trio of concepts last year did little to satisfy anyone since these rarely turn into reality. Similarly, the reveal of the Jeep, minivan and Lotus based sports car didn’t help either. By not developing a dedicated vehicle like the Volt, it appeared that Chrysler wasn’t serious about getting the most out of an EV.
However, after talking with Lou Rhodes and Doug Quigley, it appears that the engineering staff and management of the company are serious about building a complete lineup of full and range extended electric vehicles. They have good reasoning for the design decisions that have been made. The program actually pre-dates the purchase of the company by Cerberus and was instigated by then-CEO Tom LaSorda. At this point the ENVI engineering team is moving ahead with production engineering and announcements about which vehicle will be produced first as well as suppliers are expected in the next three weeks. The only question is whether Chrysler will remain a going concern long enough for the products to come to fruition.