How the Fisker Karma Works

Hybrid vehicles are changing the way drivers think about performance. Horsepower and torque numbers still play a role, but gone are the days of bigger is always better. Instead, drivers have to look to how power systems are paired and how they work together.

The power plant of the Fisker's Q Drive system -- a Quantum Technologies plug-in hybrid system that was specifically developed for Fisker Automotive -- is two 201-horsepower electric motors working through the car's rear differential. These motors draw their power from a manganese-based lithium-ion battery pack producing an open circuit voltage of about 400 volts. The Karma's charging strategy includes an on-board generator hooked to a 260-horsepower, 2.0-liter, four-cylinder, turbocharged, direct injection Ecotec engine. The Ecotec engine is produced by General Motors and used by several car companies.

All these elements tie into two broad concepts -- efficiency and performance.

Global statistics indicate pollution from cars is highest during short commutes and typical around-town errands. In addition, most Americans and Europeans -- about 60 percent -- drive their cars fewer than 50 miles per day. For almost all cars, the engine and emissions control system needs to be at a specific operating temperature to function at its peak effectiveness. During a short drive, like in the case of local errands and most daily commute driving, the engines simply don't reach that critical operating temperature.

However, the Karma's battery pack will operate the vehicle for a range of about 50 miles (80.5 kilometers) under ideal conditions -- remember, speed, terrain and driving style all play a role in depleting battery power to a greater or lesser degree -- meaning no emissions for those miles. The batteries have an estimated life of 10 to 12 years, and the charging cost is relatively small. Fisker spokesman Russell Datz estimated charging the batteries in the Fisker Karma would cost the gas equivalent of about 25 cents per gallon.

As the battery runs down, the system will kick-in the engine to drive the generator and provide additional power to the electric motors. According to Fisker, this proprietary system will be used in all future models and products. But what does all this mean for the driver? Continue reading to find out.

One of the advantages of using an electric motor to power a car is that they produce maximum torque the very instant they begin working. This is unlike gasoline engines that need to ramp-up to several thousands of revolutions per minute before producing their maximum torque. For hybrid car makers, electric motors are perfect for reducing emissions and maximizing mileage.

Cars generally use the most energy to begin rolling after a standstill. In other words, the most gas is needed to produce the torque necessary to get the car rolling. Once a car is rolling, the energy necessary to overcome the initial inertia becomes less and less, and therefore, less and less energy (gas) is used. Electric motors produce their maximum torque instantly and need less energy to move the same amount of mass. The Karma's motors produce almost 1,000 foot-pounds of torque (1,356 newton-meters) -- all of which is available immediately.

Of course, the electric motors require energy, and that's where the battery pack comes in. Most hybrid vehicles use a linked series of smaller batteries, around 1.2 volts each, to produce a combined voltage of anywhere from 300 to 650 volts total. This high voltage, especially in series hybrid cars, is necessary to provide the electric motors with enough oomph to get the car rolling.

Mark Arold, director of vehicle and powertrain engineering for Quantum Technologies, said the batteries can be recharged through traditional 110-volt AC home electrical systems, or a 240-volt AC system -- also found in homes and used to power large appliances like electric stoves and clothes dryers. According to Arold, it will take approximately five hours to recharge the Karma on a 240-volt system. While driving, the Karma's gasoline engine will run the on-board generator if the batteries drop below a certain power level, or if the demand on the electric motors cannot be met by battery power alone.

Like other hybrids, the Karma takes advantage of regenerative braking to help stop the car and take advantage of the kinetic energy potential of the car during a coast or brake situation. Regenerative braking uses generators that receive power from the wheels when the car either coasts or brakes and use the wheels inertia to generate a small charge which is then fed to the batteries.

With so many things happening under the hood, it seems as though "intelligent cars" are no longer the stuff of the future -- they're here now. And this programmed intelligence is what allows the Karma to be simply more than a battery-powered car. Read on to find out how.

While not yet able to delve into specifics, Mark Arold said the computer architecture and software controls in the Karma are programmed specifically for that car. However, he also said that the technology has been tried and tested for reliability. "This is a technology that has been developed over the years in other platforms," he said.

The software, housed in the hybrid control unit (HCU), manages the battery and engine to obtain the best results from both systems. One simple example is the Karma's auto start/stop function. Depending on inputs to the HCU, the Karma's engine will either shut itself down at long traffic lights, or keep running if necessary. This energy conservation feature is standard to most hybrids but the Karma's software takes into account multiple factors ranging from battery power level to engine load before the stop, and uses that data to make a decision. If the engine shuts off, it will automatically switch on when the gas pedal is pressed.

This same push for efficiency and performance in the Q Drive system allows the driver to operate in two modes: Stealth Drive or Sport Drive. Each mode takes advantage of the technology offered by the system in different ways and with different results:

Stealth Drive

Sport Drive

When looking at the Karma, the first standout in the design is the roof. It's formed from one large, curved piece of solar glass that helps recharge the batteries on sunny days. It also serves to improve the cabin's interior climate by absorbing and using that same sunlight rather than simply allowing it to heat the interior air. The solar roof on the Karma will add an estimated 4 to 5 miles (6.4 to 8 kilometers) of battery power per week. A larger, stationary solar array will be available for mounting on a house or garage. The array will supplement power from standard electric outlets and defray some of the charging cost.

According to the company's literature, Karma buyers can choose from three different trim levels: EcoStandard, EcoSport and EcoChic. EcoChic is the most environmentally friendly, and is based on a luxurious and animal-free approach. Leather is replaced by 100 percent Bamboo Viscose, a soft hand textile. EcoGlass trim frames authentic fossilized leaves. EcoGlass is made from recycled sand. Karma's EcoSport series incorporates hand-wrapped premium leather using a 100 percent sustainable manufacturing strategy minimizing the number of hides required and highlighting natural markings.

The Karma's controls bring a futuristic approach as well by introducing the first haptic touch screen available in a car. A haptic touch screen provides feedback senses to the user so if they push a screen button it feels and sounds like a real button was pushed. This screen allows the driver to control climate, audio, and other vehicle systems. Liquid crystal display (LCD) screens provide speed readouts and battery power levels.

For the Karma to succeed it needs more than just cool fossils in the window glass and eco-savvy. The cars are slated for delivery in 2010, but will Fisker have the momentum necessary to break into the ever-competitive (and ever-shrinking) car market? Keep reading to judge for yourself.

At the same time the production-level Karma was rolled out at the 2009 North American International Auto Show in Detroit. Mich., the company also walked out the Karma S concept, a two-door hardtop convertible. The move was met with both skepticism and grudging respect. Normally car makers wait for a new model to be accepted and proven -- typically about three or four years -- before introducing a new model. Doing otherwise, some in the industry believe, potentially takes away from potential sales of the original. But then again Karma is set on breaking the mold and doesn't seem averse to taking chances.

The company, headquartered in Irvine, Calif., and with research and design facilities in Pontiac, Mich., has received more than 1,000 pre-orders for the Karma, and they've contracted with Valmet Automotive in Finland produce the first run of cars.

Fisker spokesman Russell Datz said ultimately Fisker will produce the cars in the United States with an estimated 15,000 cars rolling off the line each year by the end of 2011, which is when the Karma S will begin delivery. Datz said, depending on demand and federal incentives, prices on future models could drop to about $50,000.

The Fisker Karma will be delivered to the first customers by the end of this year. Datz said, and the company is offering a 50-month, 50,000-mile bumper-to-bumper warranty, one of the longest in the industry for hybrid vehicles.

At the time of this writing, about 35 dealerships in the United States have partnered with Fisker to provide Karma sales and service. Datz said there were more than 80 dealers signed on with the company worldwide, and he was confident the business model would work. "This is the first premium green vehicle," he said of the Karma. "It has all the amenities you would find in a Mercedes CLS or a BMW 7 Series. It offers a combination of style, performance and efficiency never seen before."

For more information about the Fisker Karma and hybrid cars, follow the links on the next page.