UPDATE 2-Electric car adoption to remain slow-study
* Study sees EVs at 2 pct to 5 pct of U.S. market by 2020
* Deloitte forecast half of Nissan's bullish forecast (Adds details from Deloitte study on brands best positioned for electric cars, byline)
DETROIT, May 13 (Reuters) - High cost and limited performance will keep the number of electric cars at only 2 percent to 5 percent of the U.S. market a decade from now, a study by Deloitte Consulting issued on Thursday shows.
The forecast is in marked contrast to the more bullish outlook by some automakers and electric car advocates.
Nissan Motor Co (7201.T), the first major automaker to introduce an electric car, has forecast that 10 percent of new-car sales will be electric vehicles by 2020.
Deloitte expects the cost of producing batteries for electric cars to fall by 40 percent over the next four years.
The consulting firm said it expected that advanced batteries powering electric cars would cost near $600 per kilowatt hour in 2014. That would be down from near $1,000 per kilowatt hour today.
Nissan will introduce the Leaf, an all-electric car with a range of up to 100 miles on a single charge, later this year in the United States and other markets that have offered government subsidies.
The study also showed that Nissan and General Motors Co [GM.UL], the two major automakers that will introduce electric vehicles this year, face a potential problem with consumer perception of their brands when it comes to electric cars.
"The auto purchase decision in the United States is very much a brand purchase. People tend to affiliate with automotive brands," said Robert Hill of Deloitte, during a webcast to detail the study's findings."
A Deloitte survey found that 17 percent of consumers would prefer to buy an electric car from Toyota Motor Corp (7203.T), 15 percent from Honda Motor Co (7267.T) and 12 percent from Ford Motor Co (F.N).
GM's Chevrolet brand was fourth at 8 percent, and Nissan was ninth at 4 percent.
Tesla Motors, which already has a high-performance electric car on the road and is using U.S. government funding to develop a mass-market offering, was at 2 percent.
Deloitte's Hill said brands like Chevy, Nissan and Tesla might have to spend more on marketing than better positioned brands.
"The onus will be on them in a very difficult automotive market that they will bear the burden of educating consumers," he said.
Deloitte estimates that established automakers, led by Toyota, have spent $10 billion in the past decade promoting hybrid cars such as the Prius, which still make up only 3 percent of the pool of U.S. cars.
Hill said the adoption of electric cars could more closely parallel the relatively slow acceptance of 20th-century consumer breakthroughs like the washing machine than the fast embrace of more recent innovations like the cellphone.
It took the washing machine from 1930 until 1975 to go from 10 percent use in U.S. homes to 70 percent. By contrast, the jump for mobile phones to 70 percent from 10 percent in the U.S. market took a mere decade. (Reporting by Bernie Woodall; Editing by Steve Orlofsky)