Chevy Spark Electric Vehicle Prototype: A Much Closer Look

General Motors representatives handed out a lot of press releases in Sausalito, CA this week as part of GM's Electrification Experience. There was one about the company's plans to sell 500,000 vehicles with "electrification" by 2017. There was one about GM's work with ABB on reusing advanced vehicle batteries in grid storage applications (see also this). There was one about the motor in the Chevrolet Spark EV. And another about the battery. We'll talk about some of this information, but you can read them at the end of this post. What was much more interesting were two things that can't fit onto pieces of paper*: the GM's new fullthroated embrace of vehicles with plugs (whither hydrogen, whither biofuels?) and some lightly camo'ed electric Spark prototypes with the keys in them.

The message of the Electrification Experience was very obviously how GM's success with the Chevrolet Volt is guiding the company's fuel economy efforts. One can quibble about missed sales targets or too-high prices, but the fact remains that the Volt is the best-selling plug-in vehicle in the U.S. right now, and it has given GM a strong position from which to move forward in the fast-changing automotive landscape. As they wrap up their second year of sales, plug-in vehicles are far ahead of where regular hybrids were after their second year a decade ago. And, as Mark Duvall of the Electric Power Research Institute pointed out, 12 percent of all plug-in vehicles in the US were sold in October. The Volt stood at the top of that list.

The phrase "learnings from the Volt were 'sprinkled liberally'" was repeated a lot, referring to how the lessons from that project are being used withing GM. As we said earlier, Mary Barra, GM's senior vice president of global product development, said during the event that GM's future "focus" will be on plug-in technology, and at the EE, GM certainly presented its future as something other than "more car than electric." It's always been clear that this anti-EV message, the way GM first advertised the Volt, would prove inconvenient at some point. The surprise is how soon that day has come for GM.

GM's Electrification Efforts

The all-electric Spark EV is due in the summer of 2013, but in San Francisco, GM presented a wideranging look at how electrification efforts are already being integrated into the company's plans. For example, the way GM's new OnStar apps that let you interact with your plug-in vehicle (available now for the Volt, available later for the Spark), the Pecan Street project (see here and here) where the utility can track around 1,500 data points every 15 minutes from a house involved in the smart grid/plug-in car program or the work GM is doing with ABB to use old Volt batteries to assist the electric grid (where the batteries live for 10 years in a car and then 10 more years connected to the grid). The suite of electric vehicle apps is growing, too, with a Park-Tap-Charge prototype app that uses near-field-communication to send a signal from your smartphone to a Wattstation charging station to pay for and manage charging. The gamification of our world is coming online, too, with a driver challenge app that pits you and your eco driving skills against other Volt drivers, earning achievements for your green performance.

The point of all this? GM is serious about plug-in cars, making and selling more of them. The problem? Well...

"Driving" the Spark EV Prototype

The main problem with our time in the electric Spark prototype was that the loop we could drive on was around a half-mile long. Even though we could go around multiple times, there's only so much you can learn about a car in ten minutes. But we paid close attention, packing in as much as we could. For example:

• When you push the start button, the Spark performs 1,300 diagnostic checks in about two seconds.
• Underway, like most modern EVs, the Spark is smooth and quiet. Also, that battery pack gives it a solid feel around corners.
• There's no CD player.
• The Spark has Bluetooth apps (Pandora, Sticher, TuneIn) that talk to the same apps on your smartphone, displaying the info on the car's screen.
• There is creep.
• With a 0-60 time of around eight seconds, the Spark has got more-than-acceptable oomph when you get going. 45 miles per hour (as fast as we could get going) feels quite fast since you get there so quickly.

From the driver's seat, the Spark EV made us think of a mini Volt, for example with the same green battery stack graphic on the dash. The OnStar apps that talk to a Volt all work (or, better said, will work) with the Spark EV. Since there is no gas generator back-up in the Spark, there are some differences, too, including a new EV range display. Oh, and, thankfully, the center stack buttons are not touch sensitive.



On the left side of the dash screen, there are three numbers that show how much range you have left: a white number in a blue ball and then two numbers in smaller font, one above and one below. These are all calculated on the fly: the smaller numbers are the maximum and minimum range the car thinks you have left, based on the last five minutes of driving. The bigger, central number is how many miles you most likely have left, based on the last 30-50 miles of driving. So, the easist number to see is how far you can probably go, but the system also constantly updates you with information about how changing your driving style will affect your range.

The Spark is the first EV with "priority charging."

The Spark is also the first EV with "priority charging." I've asked automaker representatives for years if their all-electric vehicles had the ability to, when programmed to delay charging until nighttime when rates are lower, fill up the battery pack to a preset level (say, at least the number of miles to the nearest hospital, just in case). The answer has always been, "No." GM's response was "stay tuned," which implies that more information will be coming when the car debuts in LA. But, a bit of fiddling with the infotainment screen in the prototypes revealed the priority charging option, which performs exactly this function if you turn it on. The only difference is that GM has decided that the preset level is a battery pack that is 40 percent full. You don't get to choose. Still, this is a bit of customer convenience that we think should be widespread.



You can choose a few different ways to drive the Spark. The normal "D" mode allows for light regen, but we liked "L" which tightens that up and lets you drive (mostly) with one foot. There's also a sport mode, but all this does is adjust the throttle progression. There is no change to suspension, peak power or peak torque, just how the car reacts to pedal presses.

Stepping out to look at the car, we see an upper "grill" that is totally closed, and the only air that enters the engine compartment (aside from small leaks) comes through the lower grill (the black part in the picture below), which has an active shutter so it can be closed off to send oncoming air up and over the car when it's most efficient to do so. The Spark's underside is also covered by full underbody panels.

The front ends of the electric Sparks we got to drive still had camo on them because the official reveal isn't happening until the Los Angeles Auto Show at the end of the moth, but you can see it right now below (larger version here).



The "mini-Volt" story can also be seen in the parts that are shared between the two cars: the oil pump that cools the motor. The motor control software. The power inverter module (with one stage removed since the Spark EV has one motor and the Volt has two). The high voltage cabin heater. The 3.3-kW onboard charger.

Let's Talk Battery

GM says it will launch the car "on schedule" and "has not been impacted by A123's bankruptcy."

There are differences, too, perhaps most importantly in the battery. It's bigger than the Volt's (GM isn't saying exactly how big, just that it's "around" 20 kWh compared to 16.5 kWh in the current-gen Volt). The shapes are different, too. Rectangular in the Spark, T-shaped in the Volt. Both are lithium-ion but the Spark uses lithium-iron phosphate, as opposed to the lithium manganese spinel cells from LG Chem in the Volt. The Spark batteries come from A123 Systems, but Jon Lauckner, GM's chief technology officer, said there is no worry inside GM that A123 will not be able to provide the cells, despite that company's bankruptcy. The production process will see A123 making the cells and assembling the packs in Livonia, MI, then shipping the packs to Korea where the car is put together and then shipping it out for sale. GM says it will launch the car "on schedule" and "has not been impacted by those activities," said Bill Wallace, GM's director of global battery systems.

GM says there are no limitations on how often you can DC fast charge. None.

The Spark will likely be the first vehicle to have the SAE Combo Charger plug installed (it'll be an option. Price not disclosed). And this brings us to the most interesting "news" about the how Spark's battery performs – and something that might be contributing to GM's big new confidence in electric vehicles – which is that GM says there are no limitations on how often you can DC fast charge (i.e., get an 80-percent charge in 20 minutes). None. A presentation slide said, "A123's chemistry tolerates fast charging with modest effects on battery life." This is due, in part, to the low electrical resistance of the A123 cells, which generate less heat and provide longer life. Liquid cooling also helps keeps the battery happy. Put another way, Chris Twarog, a GM energy and battery integration engineer, called the battery chemistry "a beast."

If you're not fast charging, then it takes a little less than seven hours using a Level 2 charger and don't ask about using a standard outlet (probably 20+ hours). GM isn't announcing the range just yet, so it's unclear how often you'll need to charge, but, based on in-car display screens and the 20-kWh pack, we suspect the number will be around 70 miles. Or higher. Or lower. Whatever. This is a commuter EV, and we'll know the details soon enough.

Whatever the range ends up being, GM is preparing something called "waypoint routing" to get your Spark EV wherever it needs to go. Part of the RemoteLink app, the new Spark EV Waypoint tab allows you to input your destination and the app figures out a.) if you can make it with the energy in your pack and b.) if you can't, where to charge up along the way. It will also let you know if there is no waypoint route is available and the destination is outside of your range. The range estimates are based on your personal driving history as well as GM's data; the charging stations come from NREL. The app doesn't take anything at the final destination – how much range you'll have left, charging station availability, etc. – into account.



Aside from the powertrain, there are some differences between the gas- and electric-powered Sparks. Because of the battery, the weight balance is different (and unspecified) in the two cars. Because of the regenerative braking power, the front wheels have disc brakes and the rears have drum brakes on the ICE, whereas all four wheels have disc brakes on the EV. The EV is also heavier, by about 600 pounds, thanks to the 560-pound battery. It's easy to spot the EV badging and charge port, but it's almost impossible to tell that the EV has a slightly larger bump running on the back above the rear license plate. It's there, though.

"It's kind of impossible to keep the wheels straight with all that launch character."

Speaking of power, the Spark EV gets to peak power at 40 mph, which, combined with the car's 0-60 time of around eight seconds, means the Spark EV feels way quicker than other cars in its segment. The problem is that GM hasn't quite tamed this electric beast. With a 134-horsepower motor that puts out 400 pound-feet of torque and A123's high-power battery, the Spark EV does suffer from some torque steer. We never got to go very fast – the roughly half-mile loop route only had one straighaway where we could get up to around 45 mph – but on one acceleration, the handling felt wobbly, like we were hit by a stiff side wind. The second time – on the same stretch of road, using the same pedal application – everything felt straight and solid. Other journalists felt the same wobble, though, and Chris Kinser, electric vehicle controls manager, told AutoblogGreen that this is something the engineers noticed, too. The problem is that it's the result of using an ICE vehicle platform. They've tried to minimize it, and are still tweaking things, but it's going to be present in the finished vehicle. He said the chief pounded his fist a few times, asking them to get it right, but they just can't totally get rid of it:

It's real. We don't consider it a problem. Some people call it torque steer. The geometry of the suspension makes it so with all that torque, it's kind of impossible to keep the wheels straight with all that launch character. This car will probably maintain that character as we launch. There are a couple things we can try, but there's not a whole lot left we can do. In trying to share this platform with the internal combustion program to keep the car's costs down, we can't change that front suspension geometry. We would have liked to. It would have helped with little things like that. But it's just fundamental to how that's designed. We've done some things with the toe, and how we can align the vehicle to minimize it. We might have a little more we can do, because the tires aren't final, but it's going to have a little bit of that character.

The fact remains that these are still prototype vehicles, and GM has roughly six months to get them ready for the public. Also, there are a lot of important facts – how much the Spark will cost, where it will be sold, etc. – that GM is still keeping close to the vest, so it's hard to know how this vehicle will be received. Given the huge emphasis GM is now putting on electric vehicles, though, we imagine it will be quite the story if the Spark doesn't make a big splash.








*Yes, even though GM called the event the Electrification Experience, the idea of only-digital releases was eschewed. Go figure.

Source: Autoblog Green