Motors Are As Important As Batteries In The World Of EVs

September 11, 2019 • Alternative Energy, Electric & Hybrid Vehicle Technology Expo – Novi, Materials, MI, Science, Technology

A standing room only crowd attended Corey Steuben’s presentation on the Jaguar I-PACE and Tesla Model 3 motor configurations. (Image source: Design News)

As electric vehicles (EVs) are becoming more popular, most attention has been focused on the different designs of the lithium ion battery packs that store the electrical energy used to power the vehicle. But there is more to an EV than a big battery and the electric traction motors, or motors, are actually what provide the driving force that turns the wheels.

At The Battery Show and Electric & Hybrid Vehicle Technology Expo 2019, in Novi, Michigan, Corey Steuben, account director at Munro & Associates presented a talk titled “Tesla Model 3 vs. Jaguar I-PACE Motor Insights.” Munro has dissembled almost 400 of the presently available EVs and the evolution of these electric machines and the variety of different engineering designs has been at least as important as the improvements in EV performance that have come from progress on the lithium ion battery front.

A group of parts that display the motor configuration differences between the Jaguar I-PACE and the Tesla Model 3 (Image source: Design News)

Going For Greater Efficiency

“Some of the initial electric motors we saw, back around 2010, were using ferrite magnets, but we have seen a transition to rare earth magnets in IPM (interior permanent magnet) motors,” Steuben told Design News. “Tesla initially launched their Model S and X with induction motors that did not have the expensive rare earth magnets inside of the rotors themselves. We’ve seen with the Tesla Model 3 transition to using an IPM motor in the rear as well as an induction motor in the front, Steuben said. In general, IPM motors are considered to use electrical energy more efficiently, while induction motors can provide greater performance.

Steuben’s talk at The Battery Show compared and contrasted the motor and drivetrain technology between the Jaguar and Tesla EV models. “What we see Tesla doing, versus some of the other competitors is a high level of integration,” Steuben told us. “Jaguar has an ultra-complicated thermos-electric system, with disassociated modules throughout the car—they have multiple TXVs (thermal expansion valves) throughout the car. Tesla only has two TXVs,” he said. Munro has shown that additional weight and cost can come from having dissociated major power electronic components of an EV, largely because of the extra wiring and hoses that are required. “A high level of integration with Tesla allows them to be more efficient from a weight perspective and more efficient from a cost perspective,” Steuben told us. “The Jaguar I-Pace seems to be a step behind,” Steuben noted in his presentation.

“When it comes to motors, we see many different attempts across many manufacturers—particularly with the geometry of how they put the magnets into their internal permanent magnet motors. When you look at the ideal shape is actually very expensive to manufacture—it would be three or four sets of parabolic magnets. There is no common orientation. With the Jaguar, we see three stacked magnets, all neodymium-ferrite-born magnets which is similar to others in the magnet material. Tesla does a simple single V. We have seen six or seven variations in various forms.”

Shifts

“When it comes to paradigm shifts, Tesla pushed all serviceable fuses out of their vehicle and they pushed out the traditional park pawl—the electrically activated park pawl we have seen on every hybrid and EV on the market,” said Steuben. A park pawl is a metal hook that engages with a toothed gear to hold the vehicle stationary when it is parked—the Tesla eliminated the device and counts on the vehicle brakes when parked. “The cost of the park pawl is $30-55 when you take into account the manufacturing cost of the powder metal pieces, the springs, the returns, the electrically or hydraulically-actuated park pawl mechanism. That doesn’t exist in the Tesla Model 3…”

Steuben notes that the Tesla Model 3 also differs significantly from the Model S and Model X, which were designed for maximum performance. “The Tesla Model 3 brought the drivetrain to a different place where they could make money and it’s much further ahead than most other manufacturers.”

Senior Editor Kevin Clemens has been writing about energy, automotive, and transportation topics for more than 30 years. He has masters degrees in Materials Engineering and Environmental Education and a doctorate degree in Mechanical Engineering, specializing in aerodynamics. He has set several world land speed records on electric motorcycles that he built in his workshop.

Design News Webinar Focuses On The Tesla Battery Pack

September 6, 2019 • Alternative Energy, Automotive, Battery/Energy Storage, Electric & Hybrid Vehicle Technology Expo – Novi, Electronics & Test, Materials, Materials & Assembly, MI, Science, Technology

Tesla, and its range of electric vehicles has proven to be a major disrupter to the world’s auto industry. With the introduction of the mainstream and relatively affordable Model 3 in 2017, the company has continued to prove that electric vehicles (EVs) can be both practical and fun to own and drive. The success of the Model 3 has other car companies scratching their head and wondering how Tesla has managed to build a desirable EV that is also profitable.

Sandy Munro has presented a webinar detailing his company’s tear-down of the Tesla Model 3 battery pack. (Image source: Munro & Associates)

A Webinar

As a way to begin to answer that question, Munro & Associates, located in Auburn Hills, Michigan has disassembled a Tesla Model 3. In a 60-minute Design News webinar, automotive engineers Sandy Munro and Mark Ellis of Munro & Associates take their audience through a teardown of the Model 3 battery. Details about the pack’s design, construction, cooling system, and cell technology, among other key areas are discussed. Munro uses photos and technical descriptions of virtually every component to provide an in-depth look at the Model 3’s battery system. They also explain how Tesla’s battery compares to the batteries of its closest competitors, the Chevy Bolt and BMW i3. The webinar is sponsored by ROHM Semiconductor and Vertex. The webinar can be found here.

The Tesla Model 3 battery pack consists of 4,416 lithium ion cells in the 2170 cylindrical configuration. The pack has two sets of modules. One set has 23 bricks made up from 46 cells per brick and the other set of modules has 25 bricks made up of 46 cells per brick. The pack produces nominally 350 volts. The cylindrical cells provide a weight advantage. “Tesla using the cylindrical batteries does not have the weight disadvantage that the BMW i3 and Chevrolet Bolt have,” Munro’s Ellis said.

Munro has found that the Model 3 battery pack has some interesting features that distinguish it from the battery packs used by other manufacturers. The high-voltage electronics are centrally located close to the battery, which allows less-expensive bus bars to carry the high voltage and current levels—significantly cheaper than the heavy electrical cables that most other competitors use to carry electrical energy to separated high-voltage components.

The bus bars have another potential advantage. “They are doing everything possible in this vehicle to eliminate, neutralize, any kind of vibration in the battery pack, the electronic systems that are related to the battery and these flexible buss bars I believe are one of the things that they use to help dampen any kind of vibration in the control circuitry,” said Ellis. Tesla also uses a thermally-conducting foam blanket that covers the individual cells to help prevent vibration.

In tearing down the Tesla Model 3, Munro & Associates have found a variety of instances where engineers working on different parts of the car clearly cooperated with one another to produce a superior product—something that is not always evident in vehicles built by other car companies. “Tesla has got a cultural thing going on, not just a technology thing,” noted Sandy Munro.

A Live Presentation

In addition to the webinar, if you want to know more about how Tesla compares to its competition, Munro & Associates will display two completely disassembled electric motors; one Tesla Model 3 internal permanent magnet (IPM) and one Jaguar I-PACE IPM, at The Battery Show and Electric & Hybrid Vehicle Technology Expo 2019, in Novi, Michigan, in a talk presented by Cory Steuben, Account Director at Munro & Associates. The intent of the 25-minute forum is to dive into the key differences between the executions of the IPM motor designs. Steuben will highlight the key differences in the geometry of the rotor and stator, the placement and retention of the magnets, and specific details about the magnet material compositions and manufacturing processes. He will be prepared to answer detailed questions concerning the skew angles, fill-rates, and material compositions of the various rotor and stator parts components.

The talk is titled “Tesla Model 3 vs. Jaguar I-PACE Motor Insights” and will be presented on Tuesday, September 10^th from 10:15 AM-10:40 AM.

Although EVs presently account for just 1-2% of the US market, there may be indications that electrification is gaining both public awareness and acceptance. Webinars and presentations by companies like Munro & Associates bring greater understanding of the engineering behind vehicles from Tesla, widely acknowledged to be the EV leader. Bringing such information to light will help other automakers improve their EV designs, or more effectively enter this expanding market.

Battery, EV/HV, & Stationary Power All in One Place.

Learn everything you need to know at our in-depth conference program with 70 technical sessions in eight tracks covering topics on battery, electric & hybrid vehicles, and stationary power technologies. A talk by Munro & Associates titled “Tesla Model 3 vs. Jaguar I-PACE Motor Insights” and will be presented on Tuesday, September 10th from 10:15 AM-10:40 AM.

The Battery Show. Sept. 10-12, 2019, in Novi, MI. Register for the event, hosted by Design News’ parent company Informa.

What Are The Keys To EV Success?

August 28, 2019 • Alternative Energy, Automotive, Battery/Energy Storage, Electric & Hybrid Vehicle Technology Expo – Novi, Materials, MI, Science, Technology

GM’s Mark Verbrugge has been a part of battery research and electrification for more than three decades. His Keynote address at The Battery Show will highlight how cost and range are key to success for the EV market. (Image source: General Motors)

The two things most commonly mentioned that are holding back the growth of electric vehicles (EVs) is range and cost. Both of those areas are the subject of intense research by battery companies and auto manufacturers around the globe. Design News spoke with Mark Verbrugge, Director, Chemical and Materials Systems Laboratory at General Motors about the automaker’s efforts to find the magic that will let EVs travel farther and cost less. Verbrugge will provide one of the Keynote addresses at The Battery Show and Electric & Hybrid Vehicle Technology Expo 2019, in Novi, Michigan. His talk, titled “Standing on the Forefront of Battery Development” will be presented on Wednesday, September 11^th.

Verbrugge has been involved in battery technology and electrochemistry for his entire career. “I did my training and graduate school in electrochemistry,” he told us. “I went to UC Berkeley because they had a strong photovoltaic program—a strong clean energy emphasis in their college of chemistry,” he added.

A Long Background in EVs

When it came time to apply his electrochemistry background, Verbrugge’s timing was good. “I came directly to GM from graduate school. I worked in fuel cells to begin with, and then quickly transitioned to batteries, which were becoming more promising for (our) applications. That was the first ten years of my career, I started in 1985 and the next ten years I spent as chief engineer for our electric and hybrid electric programs,” he said. This was an exciting time for EVs as GM had just announced its first production electric vehicle, the EV-1. “I was chief engineer for the EV-1. I had the energy system management responsibilities—the propulsion system as well as the battery system,” Verbrugge said. After GM terminated the EV-1 (in 2003), Verbrugge continued development of battery chemistries and for the last ten years has been a director of research labs at GM.

With that background, Verbrugge has some well-defined ideas about how to move EVs forward. “(We need to use) earth abundant materials to get low cost, but also we have to work on fast charge, that has to be a big deal going forward—it really isn’t there today; it’s there in concept vehicles and demonstration vehicles—but in terms of high-volume pervasiveness, it’s not,” he told us.

Lower Cost With Longer Range

What are some of the lower cost materials under consideration and how can they be used? “Silicon is a major is a major emphasis for low cost materials, and it also enables fast charging. Today, all of negative electrodes are graphite. There is no pure silicon-based anode on the market. But, I think that will come in 5-10 years. Silicon is the most Earth-abundant material in the crust of the Earth,” Verbrugge said.

Silicon, at least on paper has some big advantages in replacing graphite as an anode material. “The capacity of silicon is about 4,000 milliampere-hours per gram (mAH/gm), while the capacity for graphite is about 372 mAH/gm. So, silicon can hold much more. The number of mAH is an indication of the amount of lithium that can be held. Silicon can hold much more lithium,” Verbrugge told us.

One problem however, that researchers report with silicon as an anode has been its large volume change when storing lithium ions during the charging of a battery. “Now, if you take all of that capacity, 4,000 mAH/gm, you get pulverization and cracking and a whole lot of stress issues in the batteries,” Verbrugge said.

But there is another way. “On the other hand, if you control the voltage limits, such that you use about half the capacity, about 2,000 mAH/gm, you still are way above the capacity we use of graphite today, which is about 340 mAH/gm. So we can operate at about 2,000 mAH/gm, get a significant cost reduction and a significant increase in coulombic capacity which translates to an energy density increase. For the same size and weight, you are going to get more mileage for the customer. Or you can use the same mileage as today in a lighter battery. The main thing with silicon that people are learning is don’t try to abuse the material and get too greedy with it. Use about half the capacity, then you are in good shape,” he said.

Building Infrastructure is Key

While GM is concentrating on building new EVs, it is also working with others to help grow the infrastructure that will be needed for a truly electrified transportation system. “There are a lot of public-private partnerships. I hope to foster collaboration, especially to get the charging infrastructure up and running. This is not the kind of thing you want to take onto your shoulders exclusively. To get infrastructure to move along, people have to have confidence that there are going to be vehicles as well. I’d like to encourage collaborations and investments in the space,” said Verbrugge.

The GM research director has a long-term view of how that space will grow. “I have to think gas stations are a lot more expensive than putting up a Level 2 charger in parking lots and distributed charging stations,” he said. “I think in the fullness of time, we will be much more rational—you will be able to charge anywhere, it will be monetized for those who are providing the chargers, it will be easy to understand, and it will be paid for with technologies that link to the car directly. It will be far less cents per mile for the driver, and far more efficient for society. Infrastructure is a big piece of that long-term view when we have high-volume electrification.”

Verbrugge’s Keynote address, titled ““Standing on the Forefront of Battery Development”” will cover cost, range, charging, and other topics. The talk will be presented on Wednesday, September 11^th at The Battery Show and Electric & Hybrid Vehicle Technology Expo 2019, in Novi, Michigan. He is looking forward to it. “I always get a lot of energy from these forums—I am among like-minded colleagues, typically. We are all trying to change the world and make it better. I went into this particular job area in part for that reason. So, I’ll get energy out of it. It will be fun!”

The Battery Show. Sept. 10-12, 2019, in Novi, MI. Register for the event, hosted by Design News’ parent company Informa.

Ford’s Bob Taenaka Looks At EVs' Big Picture

August 27, 2019 • Alternative Energy, Automotive, Battery/Energy Storage, Electric & Hybrid Vehicle Technology Expo – Novi, MI, Science, Sustainability, Technology

Bob Taenaka has been directly involved in every one of Ford’s electrified vehicles to date. His Keynote address at The Battery Show will highlight how battery technology is helping to lead the EV market. (Image source: Ford Motor Company)

Bob Taenaka is a Senior Technical Leader in Electrified Vehicle Battery Cells and Systems at Ford Motor Company, responsible for battery cell technology and battery system performance in support of Ford’s present and near-term future production hybrid and electric vehicles.

“I’m looking at the big picture—what are the demands of electrified vehicles for the future. Having the electrified vehicles that people really want,” Taenaka told Design News. “It’s the technology and capability that will pull the vehicles. These are advanced electrified vehicles and not regulatory push that says we need to reduce emissions and increase fuel economy and less dependence on fossil fuels,” he added.

Taenaka will provide one of the Keynote Addresses at The Battery Show and Electric & Hybrid Vehicle Technology Expo 2019, in Novi, Michigan. His talk, titled “Gateways to the Future: Delivering on Electrified Vehicle Demands” will be presented on Tuesday, September 10^th.

Sitting on a Precipice

“It’s actually quite exciting for me because I have been at Ford since 2001, so I’ve seen electrified vehicles expand to where we are right on a precipice where electric vehicles will really take off in the next decade,” said Taenaka. Prior to joining Ford in 2001, Taenaka spent 18 years with Hughes Space & Communications, serving as battery engineer for the Galileo Probe mission to Jupiter, was principal investigator or program manager for several nickel-hydrogen and sodium-sulfur battery development efforts, and held responsibility for in-orbit support on battery usage for satellite customers and ground stations. Rocket science, in other words.

Moving into electrification of transportation will take several steps. “There is a nuance,” Taenaka told us. “There are electric vehicles that are either battery or fuel cell—fully electrically powered. Then there are electrified vehicles which include those, but also include hybrid-type vehicles where you have a gas engine and an electric motor,” he said.

“A lot of industry experts have different projections. In the next ten years, I’d say, some say that electric vehicles may be 25-50% of the total vehicle market,” Taenaka explained to Design News. “As of today, I think the number is maybe around 1-3%, in that ballpark. The battery electric vehicle and also the full hybrid and plug-in hybrids and mild hybrids—a lot of these are geared to help reduce the level of CO2 emissions generated from the transportation sector. I’d say that’s where the regulatory push comes from. So not only the push but also the pull from having the performance.”

Pull as Important as Push

Taenaka thinks that having the right kind of vehicles will create this consumer-generated pull. “Having an enhanced capability will mean that people will want to purchase these advanced electrified vehicles—not only for the sense of environmental responsibility for the customer that’s driving the vehicle, but also having the advanced technology that makes their drive even more enjoyable and exciting,” he said.

Many think that reaching significant market penetration for EVs will only occur when there is cost parity with internal combustion engine vehicles. “The combination of vehicle range and vehicle cost has been one of the big obstacles to lot of people wanting to get electric vehicles in the past. The market is increasing, but to get to the level of market where states such as California are mandating, requires the vehicle costs, in particular the battery cost be reduced significantly. There have been tremendous strides that have taken place in the last 20 years on battery technology, and battery cost. Having vehicle cost parity, or even lower vehicle cost compared to conventional internal combustion engine vehicles, that’s where you are going to have a big uptick in customer demand,” Taenaka told us.

“Having similar range and similar or lower cost, equal or better capability and features—I think that’s really what drives the market,” he added.

“Since I started at Ford, the vehicle range has always been dictated by how much battery you can fit into the vehicle. And that’s another change I see happening in the next decade or so—the energy density of battery cell technology is going to be at the point where the vehicle designs will no longer be constrained by packaging the battery. We’ll start making the battery a little bit smaller and start providing other features that will fit into the space that is presently filled up by the batteries.” “It’s the combination of the range, the charging time, and the battery cost and dimensions,” said Taenaka.

Decoupling Demand From the Cost of Oil

Because Taenaka and has played a key role in battery development for each of Ford’s production electrified vehicle models launched to date, he has seen the ups and downs in the demand for EVs. “Customer desires are highly dependent upon a number of external factors. In the past, gas prices have tremendously driven the selection of big trucks and SUVs versus smaller fuel-efficient cars. When we had spikes in gas prices, consumers went with smaller cars so that their transportation costs would not be excessive. I think today people are becoming more immune to the fluctuations in gas prices and so we are tending to see more customers wanting larger vehicles,” he said.

Interestingly, because oil prices have only a secondary effect on the price of electricity, wider-spread adoption of EVs, particularly larger SUVs and pickup trucks that are on several carmaker horizons, may push buyers further away from small cars. Renewable energy might disconnect the size of the vehicle you choose from the cost of gasoline. “Geothermal, wind, and solar are not so prone to (oil) price fluctuations. I would expect the price (of electricity) to be much more stable than you would ever have with fossil fuels. Having electric vehicles plays right into that.”

Taenaka’s Keynote Addresses, titled “Gateways to the Future: Delivering on Electrified Vehicle Demands” will cover many of these topics in greater detail. The talk will be presented on Tuesday, September 10^th at The Battery Show and Electric & Hybrid Vehicle Technology Expo 2019, in Novi, Michigan.

The Battery Show. Sept. 10-12, 2019, in Novi, MI. Register for the event, hosted by Design News’ parent company Informa.

EVs Are Made Of This- REDUX

August 7, 2019 • Alternative Energy, Automotive, Battery/Energy Storage, Electric & Hybrid Vehicle Technology Expo – Novi, Electronics & Test, MI, Science, Technology

Here (once again) are 8 crucial parts that make up an electric vehicle (EV)

Introduction

Last year Design News published this description of the parts that make up an electric vehicle (EV). As EVs are finally reaching the mainstream, the information here is more important than ever. Just a couple years ago, most EVs, aside from those produced by EV pioneer Tesla, were small commuter cars whose range was limited to less than 100 miles. But now, a whole group of new medium-sized EVs are joining Tesla with sedans and crossover sport-utility vehicles that can go more than 250 miles on a single charge.

Even if you know how a gasoline engine works, EVs bring a whole new set of components, and a different language to describe them. If you are shopping for an EV, or might be in the near future, it could be helpful to know what the different pieces and systems do in a modern electric vehicle.

Here are eight of the major parts that make up an EV. Reading about them won’t provide you with a degree in electrical engineering, but it might help you understand how this exciting new technology works.

Senior Editor Kevin Clemens has been writing about energy, automotive, and transportation topics for more than 30 years. He has masters degrees in Materials Engineering and Environmental Education and a doctorate degree in Mechanical Engineering, specializing in aerodynamics. He has set several world land speed records on electric motorcycles that he built in his workshop.

(Image source: Tesla)
Traction Battery

Lithium ion batteries power electric vehicles. There are several different configurations (small cylindrical cells, pouch cells, prismatic cells). There are also several different chemistries (particularly for the cathode materials). Individual cells are combined together to create battery modules and groups of modules are combined to produce a battery pack. All together there could be several thousand individual battery cells in an EV’s pack. The voltage of a typical pack is in the 300-400 volt range. Lithium ion batteries require careful monitoring of the temperature and voltage of each cell and must be continuously balanced to avoid degraded performance and short pack life. The size of a pack is given by the number of kilowatt-hours (kWh) of energy that it can hold. A typical EV pack might hold 60-150 kWh. Some packs are air-cooled while others are liquid-cooled. Battery packs are extremely heavy (well over 1,000 pounds) and are often placed low, under the vehicle floor, to produce a low center of gravity to enhance handling performance. The bigger the pack, the further you can go.

(Image source: Jaguar)
Battery Management System (BMS)

A lithium ion pack requires the individual cell temperatures and voltages to be monitored. This is accomplished through the Battery Management System (BMS). During charging the BMS ensures that the cells have the same voltage level (usually within 0.01 volts). Without a BMS, it might be possible for one cell to dramatically overcharge, potentially causing a danger from fire or explosion. During discharge, without a BMS, it might be possible for one cell to underperform, requiring the others in a module to be drained too quickly, or at too high a rate. When you consider that a BMS has to keep track of hundreds or even thousands of battery cells and modules, the technology seems impressive. The BMS keeps your EV safe.

(Image source: Chevrolet)
DC to DC Converter

The high-voltage traction battery does the heavy lifting of propelling the vehicle. But the majority of an EV’s electrical system is actually powered by a 12-volt lead-acid battery, similar to the starting battery in a gasoline-powered vehicle. The 12-volt system operates the lights, horn, blower motors, and most of the computer systems that control the electric drive. A DC to DC Converter takes some of the energy from the 300-volt traction battery and converts it to 12-volts to run all the systems and keep the on-board 12-volt battery fully charged. On some EVs the traction battery also powers the heating and cooling system. It takes advantage of the power available to quickly make the cabin more comfortable.

(Image source: Exide)
Controller

The EV controller is an electronic microprocessor that takes driver’s inputs such as accelerator or brake pedal application and turns them into signals that transmit (usually along a CAN/BUS communications line) to the power electronics in the inverter that provide power to the motor. In many ways, the controller acts as an electronic brain, accepting inputs from the vehicle and requests from the driver and determining how to best instruct the motor to respond. The way in which the controller is programmed makes your EV drive the way it does.

(Image source: Volkswagen)
Inverter

Early electric vehicles often used brushed-DC motors that would operate on the direct current produced by the batteries and moderated by the controller. More recently, brushless DC (BLDC) motors, also known as synchronous DC, or even AC motors have arrived. Instead of direct current, they operate on alternating current. This alternating current is produced by the inverter, which takes direct current from the battery and changes it into alternating current that is used to power the BLDC motor. The frequency of the AC current determines the speed at which the motor spins. The inverter has a position sensor on the motor that allows it to time its current impulses to the motor to keep the motor spinning and producing the torque necessary to move the vehicle. The inverter takes its commands from the controller and converts them into signals for the motor. The inverter contains high-level power electronics, capable of providing several hundred volts and several hundred amps to the motor. The more robust the inverter, the more efficient and reliable your EV.

(Image source: Audi A.G.)
Traction Motor

The brushless DC (BLDC) motor is used in almost all modern EVs. It is more efficient and operates at a higher speed than the traditional brushed DC motor that the original EVs used. A typical BLDC motor has a stator, or rotor, that contains four to eight permanent magnets and that spins in the center section of the motor. The stator is surrounded by a series of electric coils that make up the commutator. The inverter provides energy to the coils in such a way that they become electromagnets that oppose the magnetism in the permanent magnets, producing motion. By timing the motion properly, the motor spins. The permanent magnets are often made with so-called rare-earth elements such as niobium or neodymium. Because electric motors produce their maximum torque at zero rpm, the motor often does not require a transmission, but can be used with direct drive, or through a gear reduction system. Some EVs use a single motor, powering the front or rear wheels. Others use a pair of motors, one at gthe front and one at the rear to create all-wheel drive. Occasionally, three motors are employed, two powering the rear wheels and one powering both the front wheels. It is also possible to build motors into the wheels, providing four motors, one for each wheel position. Motor cooling can be accomplished either by air-cooling or liquid cooling. The more power (in kilowatts, or kW) your EV produces, the more performance it will provide you, provided the cooling system is capable of keeping the motor temperature in check.

(Image source: Audi A.G.)
Regenerative Braking

One way EVs produce high levels of efficiency is by capturing energy normally lost to heat during braking. When a vehicle slows down, the motor can operate as a generator, producing electricity at the same time it slows the vehicle. The electrical energy produced by the regenerative braking can be applied to the battery, helping to recharge it slightly. The amount of regenerative braking can be adjusted (using the controller) to provide a significant reduction in speed without using the vehicle’s normal hydraulic brakes. Regenerative braking can add more than 20% to the vehicle range during stop and go driving in the city. Some EVs have aggressive regenerative braking, allowing nearly one-pedal driving where you almost never need to touch the brake pedal.

(Image source: Jaguar)
Chargers and Charging

Most EVs have an on-board charger that is capable of plugging into normal 120-volt household current (Level 1 charging) or into a special 220-volt line (Level 2 charging) that is wired into the home garage circuit. Onboard chargers are limited by the amount of current that the home circuits can provide. Typical level 1 charging can produce 1.9 kilowatts (kW) of power and provides about 4 miles of range for every hour of charging. Level 2 charging is generally limited to 3.3 kW to 6.6 kW and can provide up to 20 miles of range for every hour of charging. Fast DC charging, also called Level 3 charging, is also possible for some EVs. In this case a special plug sends direct current directly into the battery at power levels of 150 kW or greater. A Level 3 charger can add 50-150 miles of range in a half an hour of charging. At the very least you need Level 2 charging at home to ensure your EV has a “full tank” every morning. If you want to make any long trips in your EV, Level 3 charging capability is a must.

(Image source: Siemens)

Drive World with ESC Launches in Silicon Valley

This summer (August 27-29), Drive World Conference & Expo launches in Silicon Valley with North America’s largest embedded systems event, Embedded Systems Conference (ESC). The inaugural three-day showcase brings together the brightest minds across the automotive electronics and embedded systems industries who are looking to shape the technology of tomorrow.

Will you be there to help engineer this shift? Register today!

Pre-owned Electric Vehicle Models Provide An Affordable Way To Go Electric

July 31, 2019 • Alternative Energy, Automotive, Battery/Energy Storage, Electric & Hybrid Vehicle Technology Expo – Novi, Electronics & Test, MI, Science, Sustainability, Technology

INTRODUCTION

Electric Vehicles (EVs) are finally reaching a stage where they can be used as practical vehicles. Increased range (some EVs can go over 250 miles on a charge) and the deployment of EV charging stations nationwide is helping to inch electrification of transportation toward the mainstream. But what of all of those vehicles that represented the early attempts at building and selling EVs? Many of them are available on the used market, often for surprisingly low prices.

In the not too distant past, some automakers sold EVs that were designed solely to comply with the California regulations that required that car makers offer a percentage of their fleet with zero emissions. Others embraced the idea that electrification might be the future. The EVs built in that first wave, between 2011 and 2016, were typically small, expensive, and had a range of 60-100 miles on a charge.

Buying a used car is always a risk—even with good documentation and service records, it is still hard to know how well a vehicle has been maintained and whether it has been abused. The good news about used electric vehicles is that EVs, with fewer moving parts than traditional gasoline powered vehicles, have been shown to be mechanically robust and reliable, requiring little beyond routine maintenance. In addition, because of their limited range, they often have accumulated quite low mileage for their year, another positive.

But there is one major concern: the battery pack. The condition of the lithium ion battery pack that powers EVs depends enormously on how it has been treated during its lifetime. Repeated fast charging, completely depleting the battery, or operation at hot or cold temperature extremes can result in a battery pack with reduced capability when compared to when it was new. Just normal aging of a pack can result in a reduction of around 5% capacity per year. Many car makers placed warranties on their battery packs, typically 8 years or 100,000 miles. Some early EVs on the used market are nearing that age limit. So the range quoted for a new EV in 2015 may not be reached by a used EV in 2019 with an aging pack.

There is some good news for those contemplating a used EV. The cost of lithium ion batteries has fallen dramatically, from well over $1000 per kilowatt-hour (kW) just a few years ago to less than $200 per kWh today. There has grown up a cottage industry of specialists who can rejuvenate a used EV pack, replacing malfunctioning cells and returning them to nearly new capacity. There are also some aftermarket computer tools available to assess to condition of a pack—suffice it to say that any buyer of a used EV should do their homework before considering such a purchase.

To examine the prices of some available used EVs, Design News reached out to Kelly Blue Book (KBB) to provide current used car prices. KBB is an industry standard for reliable used car pricing. We chose to price our cars as if they were in Very Good condition and if we were buying from a dealer. The prices when buying from a private seller might be slightly lower. We reported the current used price for the first year a vehicle was available, the used price for a 2018 model of the vehicle or the last year it was available, and the new vehicle price (MSRP from KBB) for the last year it was available, or for 2019 if the vehicle is still available.

With prices that range from less than $5,000 to more than $60,000, here are some used EVs to consider.

Senior Editor Kevin Clemens has been writing about energy, automotive, and transportation topics for more than 30 years. He has masters degrees in Materials Engineering and Environmental Education and a doctorate degree in Mechanical Engineering, specializing in aerodynamics. He has set several world land speed records on electric motorcycles that he built in his workshop.

(Image source: BMW)
Nissan Leaf SL (2011-2019)

                                    KBB Price

New     2019                $35,030           Range: 215 miles

            2018                $23,982           Range: 150 miles

            2011                $5,419             Range: 72 miles

Battery Warranty: 8 years/100,000 miles

Summary:

Nissan was one of the first of the major car companies out of the gate, into production with its all-electric Leaf in 2011. Since that time the company has sold more than 300,000 Leaf’s making it the biggest selling EV in the world. The Leaf is easy to drive, reasonably comfortable, and well-made, and as long as you don’t drive more than 70-100 miles in a day, a used Leaf would make a fine commuter car. The larger 30 kWh battery pack arrived in 2016, but there have been questions about whether it is degrading faster than the original 24 kWh pack. The earliest Leafs are also reaching the end of their 8 year battery warranty period. An all-new Leaf was introduced for 2018 and has considerably better range.

(Image source: Nissan)
BMW i3 (2014-2019)

                                    KBB Price

New     2019                $44,450           Range: 126 miles

            2018                $34,620           Range: 114 miles

            2014                $13,319           Range: 80 miles

Battery Warranty: At least 70% capacity for 8 years or 100,000 miles

Summary:

When BMW introduced the i3 in 2014, it was clear that the German car company wanted to make a statement about its EVs. The i3 had a unique shape and architecture that it didn’t share with any other vehicle in the BMW lineup. Its carbon-fiber reinforced body helped reduce weight while its interior was made largely from recycled and recyclable materials. The i3 also was available with a two cylinder range-extender gasoline engine to help assuage those range anxiety fears. Most of all, the i3 is a BMW—its performance and driving characteristics set it apart from other EVs, new or used.

(Image source: BMW)
Smart fortwo electric drive (2013-2018)

                                    KBB Price

            2018                $24,550           Range: 75 miles

            2018                $14,140           Range: 75 miles

            2013                $3,557             Range: 75 miles

Battery Warranty: 8 years, 62,000 miles

Summary:

The Smart fortwo was the smallest car available in the U.S., and was when the electric drive version was introduced in 2013. With a small 17.8 kWh battery pack, tight dimensions, an incredibly tight turning circle, and just two seats, the fortwo was really designed to be a city commuter. Fortunately, it’s a task at which the Smart excels and that small battery pack can be charged on a Level 2 (220-volt) charger in just a few hours. A cabriolet version is also available for open-air electric motoring. Unfortunately for those of us who like tiny vehicles, Smart stopped selling its cars in North America at the end of 2018.

(Image source: Smart)
Fiat 500e (2013-2017)

                                    KBB Price

New     2017                $32,795           Range: 87 miles

            2017                $10,101           Range: 87 miles

            2013                $6,648             Range: 87 miles

Battery Warranty: 8 years, 100,000 miles

Summary:

Originally available only in California, the Fiat 500e has found its way across the country, although finding one locally may not always be easy. It’s a subcompact without a lot of rear seat room, and its range is limited, but around town the Fiat 500e is a stylish and fun way to travel. Resale value is obviously low, which is good news if you are in the market for a fun, but cheap, used EV. The 500e was discontinued in 2017.

(Image source: Fiat)
Volkswagen e-Golf (2015-2018)

                                    KBB Price

New     2018                $37,845           Range: 125 miles

            2018                $24,197           Range: 125 miles

            2015                $11,708           Range: 83 miles

Battery Warranty: At least 70% capacity for 8 years or 100,000 miles

Summary:

The Volkswagen eGolf is based upon the gasoline-powered version of the car—that’s not a bad thing if you are an avid driver as the Golf has long been considered one of Europe’s best handling small cars. The somewhat high price of a used eGolf (relative to other used small EVs) demonstrates the enthusiasm that many have for these cars. VW has announced big plans for electrification of its fleet in coming years, so buying a used eGolf might mark you as an early adopter among fans of the company. 2018 was the last year for the eGolf in the US.

(Image source: Volkswagen)
Chevrolet Spark EV (2014-2016)

                                    KBB Price

New     2016                $26,000           Range: 82 miles

            2016                $9,658             Range: 82 miles

            2014                $7,726             Range: 82 miles

Battery Warranty: 8 years, 100,000 miles

Summary:

The non-electric version of the Chevrolet Spark was one of the least expensive cars in the U.S. and its electric cousin was available for around $20,000 after incentives. The EV version had a robust 140-horsepower which allowed the small car to race to 60 mph in just over 7 seconds. Initially the Spark EV was only available in California and Oregon—at the end of its run it also was available in Maryland.

(Image source: Chevrolet)
Mitsubishi i-MiEV (2012-2017)

                                    KBB Price

New     2017                $23,845           Range: 62 miles

            2017                $9,765             Range: 62 miles

            2012                $5,069             Range: 62 miles

Battery Warranty: 8 years, 100,000 miles

Summary:

The Mitsubishi i-MiEV is all about its low initial purchase price. What is hard to live with is a range of just 62 miles, less if it is drive hard. Its funky looks and small size scream “EV” which may be a good or a bad thing, depending upon your goals. If you have a short commute, want to get your EV feet wet without spending much money, and want the world to know you are driving an EV, the i-MiEV might be for you. 2017 was the last year for the i-Mev.

(Image source: Mitsubishi)
Tesla Model S (2012-2019)

                                    KBB Price

New     2019                $86,200           Range: 250 miles

            2018                $75,614           Range: 250 miles

            2012                $34,627           Range: 230 miles

Battery Warranty: 8 years, 125,000 miles

Summary:

The Tesla Model S has had a presence in and impact on the EV market far beyond its sales numbers. Over the years it has been available with a number of different battery pack sizes that can provide a range over 300 miles on a charge, and with single and dual motors for performance up to and including “Ludicrous.” Prices can easily exceed $135,000 for a fully optioned new Model S—for a used one it all comes down to what you can find and how it is equipped. Add in the Tesla Supercharger system of nationwide charging stations and a used Model S is an attractive prospect.

(Image source: Tesla)
Tesla Model X 75D (2016-2019)

                                    KBB Price

New     2019                $83,200           Range: 237 miles

            2018                $73,545           Range: 237 miles

            2016                $59,179           Range: 237 miles

Battery Warranty: 8 years, unlimited miles

Summary:

Tesla was ahead of the curve when it introduced an electric cross-over utility vehicle (CUV), the Model X. With competition now on the horizon from Jaguar, Audi, Porsche, BMW, Nissan, Hyundai, and Mercedes-Benz, the Tesla Model X still has the specifications to withstand the onslaught. Every Model X has twin electric motors, a whole range of standard features, and unique “Falcon Wing” rear doors that open upward instead of outward. An optional 100 kWh battery in place of the 75 kWh battery can provide a range of up to 295 miles. The Model X can also access the Tesla Supercharger charging network.

(Image source: Tesla)
Tesla Model 3 (2018-2019)

                                    KBB Price

New     2019                $45,200           Range: 249 miles

            2018                $46,467           Range: 249 miles

Battery Warranty: 8 years, unlimited miles

Summary:

The Tesla Model 3 is the reasonably priced electric vehicle that Tesla has promised all along. Although its base price is in the mid-$35,000 range, the only versions made so far have been significantly more. In fact, it might be possible to buy a used Model 3 for more than a new one, depending upon which battery and options are involved.

(Image source: Tesla)
Fisker Karma (2012) (Plug-in Hybrid)

                                    KBB Price

New     2012                $103,000         Range: 50 miles (on battery)

            2012                $35,775 est.    Range: 50 miles (on battery)

Battery Warranty: none

Summary:

The Fisker Karma was a beautiful four-passenger sedan that lasted just one year in production. It was a hybrid with a 50-mile battery range and an auxiliary gasoline engine to provide additional range. Since the company went out of business, there is no battery or drivetrain warranty, nor a dealer network, so buying one could be a true risk. On the other hand, used prices for Fiskers seem to be on the rise. A new Fisker venture is underway with a promise to build new EVs in 2019.

(Image source: Fisker)
Chevrolet Volt (2011-2019) (Plug-in Hybrid)

                                    KBB Price

New     2019                $34,395           Range: 53 miles (on battery)

            2018                $21,060           Range: 53 miles (on battery)

            2011                $9,682             Range: 35 miles (on battery)

Battery Warranty: 8 years, 100,000 miles

Summary:

Chevrolet recognized that “range anxiety” would be a big factor in the acceptance of electric vehicles, so it equipped the Volt with a 1.4-liter four-cylinder gasoline engine that would take over after the battery reached a certain level of discharge and provide an extended range of over 350 miles. It was a smart way to introduce the American public to EVs and the Chevrolet Volt remains a practical alternative to the Nissan Leaf on the used EV market. A second generation of the Volt arrived in 2016, with more battery power and a more usable interior. 2019 will be the last year for the Volt, a victim of the insatiable US market demand for pickup trucks and SUVs.

(Image source: Chevrolet)
Chevrolet Bolt (2017-2019)

                                    KBB Price

New     2019                $41,895           Range: 238 miles

            2018                $29,166           Range: 238 miles

            2017                $25,006           Range: 238 miles

Battery Warranty: 8 years, 100,000 miles

Summary:

Arriving just ahead of the Tesla Model 3, the Chevrolet Bolt, on paper at least, appears to be just the EV that everyone wanted. Sales have been dismal however, despite the range and performance that the Bolt EV can offer.

(Image source: Chevrolet)
Ford Focus EV (2012-2018)

                                    KBB Price

New     2018                $29,120           Range: 100 miles

            2018                $19,223           Range: 100 miles

            2012                $6,361             Range: 76 miles

Battery Warranty: 8 years, 100,000 miles

Summary:

Almost unnoticed, the Ford Focus EV has been soldiering along for a six year run that saw it continue to improve. This is definitely a “below-the-radar” kind of car, but if you want to drive an EV, but don’t want your neighbors to know, this car might be for you. The last Ford Focus EV model year was 2018.

(Image source: Ford)

Could Solar-Powered Cars Become Practical?

July 25, 2019 • Alternative Energy, Automotive, Battery/Energy Storage, Electric & Hybrid Vehicle Technology Expo – Novi, MI, Science, Technology

Toyota has placed enough high-efficiency solar cells on a Prius to gain up to 27 miles of driving range during a sunny day. (Image source: Toyota)

The idea of a solar-powered car is an appealing one. The first official solar car race was the Tour de Sol in Switzerland in 1985, and since that time similar races have taken place in the US, Australia, and Europe. The vehicles for such competitions are usually built by universities, often in partnership with car makers and aerospace firms, and are usually highly aerodynamic, single-seat machines having little to do with practical transportation.

Now, Toyota has announced that it is partnering with Sharp and the New Energy and Industrial Technology Development Organization (NEDO) in Japan to test a plug-in Prius hybrid whose power system has been augmented by highly-efficient solar cells. According to a Toyota news release, “The trials aim to assess the effectiveness of improvements in cruising range and fuel efficiency of electrified vehicles equipped with high-efficiency solar batteries.”

Roof Tops

Anyone who is familiar with solar cells will be immediately doubtful about their on-board use to power a vehicle. Photovoltaic (PV) cells are great in stationary applications where, on a rooftop or in a field they can cover a large area and generate electricity, even when the sun is partially hidden behind clouds. In fact, in the early days of electric vehicle (EV) acceptance, it wasn’t uncommon for EV owners to use a rooftop solar array to help charge their vehicles. But finding enough surface area on a vehicle to mount enough solar panels to make a difference is a problem.

Solar panels have been used on some EVs—the original Nissan Leaf for example had an option of a small solar panel on its rear spoiler whose purpose was to maintain the charge of the car’s 12-volt auxiliary battery. Likewise, Toyota has offered solar panels for the roof of its Prius that generated enough power to run a cooling fan in the cabin.

On the Road

Early in 2019, German company Sono Motors announced that it would be going into production with its Sion solar-powered EV. Similar in size to a Nissan Leaf, every flat surface of the Sion is covered in solar cells. The company claims that on a sunny day, the Sion will gain about 19 miles of driving range from the 1.2 kilowatts of output that the solar panels can produce. Although the company plans to eventually sell its Sion worldwide, initially it is concentrating on the European market.

Sharp has developed a high-efficiency solar battery cell with a conversion efficiency of 34 percent (about 10% higher than current commercial cells) and modularized it to create an onboard solar battery panel for Toyota. The solar cell is a thin film about 0.03 mm in thickness. Toyota installed this panel on the roof, hood, rear hatch door, and other parts of its “Prius PHV” to produce a car that could be tested and demonstrated on public roads.

According to the news release, “By enhancing the solar battery panel’s efficiency and expanding its onboard area, Toyota was able to achieve a rated power generation output of around 860 watts.” The result is a system that charges the driving battery while the vehicle is parked and also while it’s being driven. During a full day, Toyota estimates the solar panels will add about 27 miles of EV driving range to the Prius. Because an average person in the US drives around 29 miles per day, the use of solar power for EV charging is beginning to look more practical.

The Battery Show and Electric & Hybrid Vehicle Technology Expo 2019 conference will take place in Novi, Michigan on September 10-12, 2019. Four days, eight tracks, and over 80 sessions, curated by industry experts will bring battery and electric vehicle technologies into clear focus.

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