It was dark and rainy, and the battery on his nifty Mini E electric car was almost gone.

Paul Heitmann rolled quietly through the suburban New Jersey gloom, peering through the rain on the windshield, not sure what he was looking for, anxiety turning into panic. He needed juice. He spotted a Lukoil gas station, which was closed, and beside the point, anyway.

But beyond the pumps, there was a Coke machine, and it was lit up.

“I thought ‘Finally!’ because I knew if there was light, there would be electricity,” he said. “I managed to find the outlet behind the Coke machine and plugged in.”

As many of the auto companies tell it, next year may be the year that the massive U.S. auto industry really begins to go electric.

The all-battery Leaf from Nissan is scheduled to go on sale in November. General Motors will begin selling the Chevy Volt, a primarily electric car (with a small auxiliary gasoline engine that kicks in to boost the car’s range). Ford has plans to produce an electric commercial van. The Obama administration has doled out $2.4 billion to companies involved in producing batteries and other parts of electric cars.

“We have to get on with the electrification of our industry,” William Clay Ford Jr., chairman of Ford, said during a visit to Washington on Monday.

“I know we have to have an electric car,” GM Chairman Edward Whitacre Jr. told reporters last week.

But overshadowing prospects for the transition of the vast U.S. auto fleet to electric — and the billions of dollars the automakers have invested in the switch — is the question of whether anyone beyond a sliver of enthusiasts will soon embrace the newfangled cars, which force drivers to rethink their habits and expectations of convenience.

For now, the only major automaker with a fleet of new all-electric vehicles priced for mainstream consumers is BMW, with its 500 Mini E electrics in what the company describes as a test of the technology. To judge from interviews with drivers and more than a dozen of their blogs, it has also proved to be a test of consumer adaptability.

The electrics pose two primary challenges to convention: When fully charged, electric cars generally cannot travel even half the distance that a conventional car can go on a full tank. And once the battery is depleted, there are few places to recharge besides home, and the charging process can take hours.

Heitmann, for example, sat in the dark beside the Coke machine for one midnight hour to make sure he had enough charge to make it the four miles to his mother’s house.

“I sat there looking at the gas pumps that said $2.45 a gallon,” he recalled. “And I thought, ‘What I wouldn’t give to be able to use that.’ Two and a half dollars, and I could have gotten another 25 miles.”

Many of the Mini E drivers are rhapsodic about the car’s performance and the promise of environmental benefits, as is Heitmann. They have been, after all, willing to join a select group that pays about $850 a month to lease the cars and have a recharging wall box installed at their homes. But when Mini E drivers get together, their talk often turns to the art of maximizing the number of miles they can get with a single charge.

Their tricks: They slow down — driving fast takes more power per mile because of aerodynamics and other factors. So some poke along at 55 mph on the highway as other drivers zoom past. In a pinch, they turn off the heater or the air conditioner, tolerating a chill or a sweat to get another mile. And they have learned that in very cold weather, they must further restrict their travels. When temperatures dip, the normal 100-mile range can shrink to as little as 80.

“I was shocked,” said Robert Hooper, 44, a computer manager from New Jersey, when he realized how much his range shrank in the cold. When he considers the prospects of the 70-mile trip to his fiancee’s house in the cold, he said, “I’m nervous.”

The car companies staking investments on electric cars argue that such difficulties will soon be minimized. They say that the cars, now pricey, will be manufactured more cheaply as they are produced in greater numbers. Battery innovations will provide greater range at lower cost. The problem of the cold will diminish as heating systems are better developed.

Perhaps most critically, they say, public charging stations will become far more common.

There are about 117,000 gas stations in the United States.

By contrast, a database of public recharging stations maintained by Tom Dowling, an electric-car enthusiast in California, lists 734 public charging stations in the United States, with the vast majority in that state.

Dowling said the comparison to gas stations isn’t completely fair because most charging can be done at home. But the lack of public charging stations is a widely recognized hurdle for the electrification effort.

In conjunction with Nissan, a company called Ecotality has a $100 million federal grant to set up about 7,000 stations in five states.

Given these hurdles, some automakers and environmentalists have cast a wary eye on the enthusiasts. “I would argue that the case for the electric car is not proven,” said Jim O’Donnell, chairman and chief executive of BMW North America, which built the Mini E. “We’re not quite sure people are willing to go for it. We’re asking consumers to pay more and get less. Our view is: Proceed with caution.”

Nevertheless, the enthusiasts remain optimistic, many hoping to lead the way to weaning the United States from foreign oil and others concerned about the environment. John DeCicco, a University of Michigan lecturer and former senior fellow at the Environmental Defense Fund, figures the carbon footprint of the Mini E is about half that of the gas version of the Mini Cooper.

“The car is a joy,” said Timothy Gill, 59, a software engineer from Maplewood, N.J., who drives a Mini E. His previous car was a ’93 Toyota Corolla and he long ago began bringing cloth bags to the supermarket for environmental reasons. His new license plate says “WHY GAS.”

“The range of the cars and the infrastructure has to improve,” he said. “But that will happen.”