The nation's largest manufacturer of electric cars has gone bankrupt, downed by the one-two punch of energy unawareness and safety worries. Yet the electric vehicle industry, which has been predicting a boom any minute for the last 30 years, is still insisting that a battery-powered America lies just beyond the next abandoned gas station.

Sebring, Vanguard Inc., with headquarters in Columbia Md., lost its shirt selling 2,150 electric two-seater "CitiCars" between 1974 and 1976. "We sold more than everybody else put together, but we sold them too cheaply," summed up general manager Robert Sanders at the assembly plant in Sebring, Fla.

The company last week sent its creditors and suppliers offers of $250,000 in promissory notes, which if bought, will allow Sebring Vanguard to unfreeze its assets, reorganize and again start making new, improved electric cars.

"We're moderately optimistic" that the offering will be said by its April 15 deadline, Sanders said. "We're back-ordered 400 to 500 cars right now but we have no capital."

The court-ordered bankruptcy papers say the company had lost $2 million when it shut down its manufacturing operation in August 1976. The documents disagree with Sanders on the reason, however: they blame a September 1974 critique in Consumer Reports magazine that, to put it mildly, said the little car was unsafe. In Sanders' words, the article described a CitiCar accident as "all blood and guts, trials of plastic bits . . ."

"People forgot there was a gasoline shortage," added Gilbert Illch, president of Aero Chevrolet in Alexandria. His company sold "eight or nine" CitiCars in 1974 and 1975 at a cost of about $2,995, he said, but then "demand dropped off and we sold them for whatever we could get . . . as long as there's no thought about a gasoline shortage, the majority of people don't want something that won't go but 30 miles an hour."

The problems facing Sebring Vanguard's cars are common to the half-dozen surviving manufacturers of the estimated 3,000 electric vehicles now on the nation's roads. Convinced that the looming energy crisis will eventually bring the public flocking to rechargeable transport, they are hanging on in the meantime by ministering to a few specialized needs.

"The jitney is sort of saving our life," said Harry Yoder, president of the Battornic Truck Corp. of Boyertown, Pa. He sold 18 electric mini-buses to a mushroom farm in Worthington, Pa., where workers must be ferried in and out of the abandoned limestone mine tunnels where 100,000 pounds a day of mushrooms are harvested from the dank dark.

Yoder said his firm sold 160 trucks in 1974, the year after the Arab oil embargo and the best year ever for the electric vehicle movement. Last year he sold 25.

"There is an existing electric vehicle industry that people just forget about," said James F. Norberg, president of ESB Inc. in Cleveland, a major battery supplier. There are, he said, electric fork-lift trucks, tractors and locomotives used in mines, golf carts and a number of personnel, baggage and box-handling vehicles based on the golf cart design.

"It's a tidy and substantial little business, not dependent on the electric cars, which haven't ever got off the ground yet," he added.

"At the moment the owner (of an electric vehicle) has to be a dedicated kind of person who knows he has something special and is willing to give it special kind of care," said Edward Campbell, executive secretary of the Electric Vehicle Council, the budding industry's trade association.

The council is funded partly by electric utilities through their Edison Electric Institute and partly by the vehicle manufacturers and parts suppliers. They all agree on two things: the sad state of the art of battery making is at the root of their problems; and a current $160 million expression of federal interest is the key to a possibly golden future.

The CitiCar I, which looked like a large wedge-shaped doorstop, carried eight special six-volt batteries weighing 300 pounds under its seat. These powered a 3.5 horsepower electric motor that could generate a speed of 45 m.p.h. going downhill, but only 25 m.p.h. or so uphill, and that only in warmish weather. More power needs more batteries, which means more weight, which eventually means less power.

After 50 miles or so at an average of 38 m.p.h. (not fast enough for interstate highways), the car had to be plugged into a regular household electric outlet and sit there getting juice for eight hours. The window sticker on Illch's last CitiCar includes the item: "extension cord, $7.50."

At least two-dozen pairs of chemicals have been found that produce more electric current than the lead-acid pairing now used in most batteries, according to James F. Norberg, president of ESB Inc. in Cleveland, a major battery supplier.

Most however, have serious problems: overheating, cost, danger or short lifespan, he said. Meanwhile, research proceeds on a near-crash basis nationwide to beat the weight-power problem. He said that success would result in a revolution in transport, utility power load timing, solar energy applications and in dozens of other fields.

Small as it is, the electric vehicle industry is awash with rumors as to who has made what breakthrough in the battery field and what kind of requirements the Postal Service will have next year.

With 383 electric jeep-type delivery cars, made by an American Motors susidiary, the U.S. Postal Service is the electric vehicle industry's largest single customer. Fleet manager Donn Crane said he will buy 750 more electric vehicles this spring, and more later if problems of power loss in cold weather can be solved. "Overall, I'm very, very happy with them," he said. Most of his electric cars are used in California.

Maintenance, depreciation and operating costs total $1,036 a year per car, he said, $300 a year less than for his gasoline-powered vehicles. Larger models with more range and speed, from Jet Industries of Austin, Tex., are being tested, Crane said.

The Department of Energy has begun a five-year $160 million spending program to stimulate private electric vehicle research, demonstration and development projects. Passed in September 1976 over President Ford's veto, the program "will change everything, but slowly, according to Campbell of the Electric Vehicle Council.

"The car's not perfected to where you can rely on it yet," concedes auto dealer Illch. "I don't think they'll ever get an electric car to do what those can do," he said, pointing to a row of cars hitched to big trailers and boats. "But then, I never thought we'd get to the moon either."

The Electric Fuel Propulsion Corp. of Detroit is going after just that market. The company will set up 500 charging stations in Southern California supermarkets and gas stations this year to prepare for its new "Silver Volt," a four-passenger car with a 500-mile range, top speed of 70 m.p.h. and a 45-minute recharge capacity on special lines. Using lead-cobalt batteries, the car will sell for $11,900 when it becomes available in 1979, according to company president Robert Aronson.

"Major production will start in 1980," he said. "By 1985 the big guys will jump in - General Motors plans it already - and by 1988, 1989 with everybody in, we'll have maybe 5 or 10 million electric cars on the road . . .

"People will buy them. We've been planning this for 11 years. We'll capture 5 to 10 percent of the Lincoln-Cadillac market at least."

Most everyone agrees that some kind of large-scale program to set up recharging stations will have to precede widespread use of electric cars, since the batteries must be recharged so frequently and checked often for wear and tear. At the moment, the available cars are designed for use in city traffic, but few city residents have garages in which to park an electric car for recharging.

"There are proposals, pretty far-fetched, for some kind of parking meter with a plug in it," said Campbell "but for the moment I suggest you move to the suburbs."