Fisker Karma Plug-in Hybrid
Shane Stroud
Mr. Norman
4/7/13

The purpose of this paper is to introduce and explain the Karma hybrid built by Fisker automotive. I will also inform a potential customer or inquirer about the technologies and features of the Karma. This paper will show the technical information about the car and explain the features that make it a car of the future. I will give a detailed analysis of the powertrain all the way to the solar power roof that helps recharge the batteries. Along with the abilities of the car I will also state the problems and recalls the Karma has encountered. The Fisker Karma is currently the only full sized plug-in hybrid luxury sedan on the market. It has a 52 mile per gallon equivalent that comes from the use of a General Motors sourced Ecotec engine that acts solely as a generator to charge the 20 kWh lithium ion batteries. That battery powers the Q-Drive hybrid drivetrain that consist of a pair of 161 hp electric motors. The roof of the Karma is a full sized solar panel that constantly charges the battery. “The solar roof is capable of generating a half kilowatt-hour a day and was estimated to provide up to 4 to 5 miles (6.4–8.0 km) of additional range a week assuming continuously sunny days” (Sherman). The car produces 403 horsepower and 959 pound foot of torque. The powertrain in the karma is a 2.0 liter 4 cylinder repurposed Chevy Ecotec engine that is solely a generator. Due to the fact that the gasoline engine acts only as an engine it’s not a true hybrid, it is a series hybrid. That could also be referred to as a ranger extended electric vehicle. Even though it is a series hybrid it can be ran strictly on the battery pack which is why some refer to it as a plug in hybrid, but if you use just the battery pack you may only get about 30-50 miles range out of it. When it is in extended range mode and the internal combustion engine is used as a generator you get an average of 250 miles range. While in extended range the motor powers just the generator to provide power to the rear wheels, but also recharges the battery as it power the car allowing the driver to switch back to
Electric mode if they please.
The battery pack in the Karma is a mid-mounted 336 volt lithium ion battery produced by a123 systems. It is marketed as a Nano phosphate® lithium ion battery pack that consist of 315 individual cells. A123 systems state that their Nano phosphate technology is a “Conductive Lithium Storage Electrode (NFSE) not to be confused with standard lithium iron phosphate” (Chiang pg. 1). “The Nano phosphate is an engineered Nano scale material with specific structural and chemical properties designed to maximize the performance of lithium-ion batteries” (Chiang pg. 1). The difference between a regular lithium-ion battery back and a Nano phosphate battery pack is that when the chemical reactions happen in a regular lithium-ion they are generally slow and because of that it limits the power output of the battery which means they have a lot of energy, but produce low power. Whereas the monophosphate batteries “increase the cathode surface area with the electrolyte, which allows for faster lithium insertion and thus more power” (Chieng). Another huge benefit of the Nano phosphate technology is it maintains its power as the charge decreases whereas regular battery packs produce less power as the charge declines. The battery pack in the Karma can sustain 7,000 cycles from fully charged to completely discharged with little to no resistance increase or power loss. The Karma comes with a standard 110 volt charger and a 220 volt charging station is optional with the car. The charge time is anywhere from six to fourteen hours depending on what charger you use and the charge level of the battery pack. Battery Type | Lithium ion battery pack with Nanophosphate technology | Battery Voltage | 336 V | Battery Capacity | 20.1 kWh | Charging | 3.3 kWh with 110V & 220V capability