LOS ANGELES — It was a summer weekend in Southern California, and

Tim Bush, a 36-year-old insurance agent from Orange County, wanted to take a family trip to Santa Barbara, about 130 miles up the coast, in his new Hyundai crossover.

Before he could set off, though, Bush had to call a Hyundai hotline to confirm that the journey was possible. The call set in motion a scramble by Hyundai employees to ensure that Bush’s extraordinary vehicle — a Tucson FCEV, the first hydrogen-powered fuel cell electric vehicle leased in the U.S. by Hyundai — would be able to make this otherwise ordinary trip.

"You should have seen us. We were running around like ants,” Sandy Zielomski, who runs Hyundai’s concierge service, said in an interview a few weeks later. “He can’t possibly know what was going on behind the scenes.”

From Seoul to Stuttgart and Detroit to Tokyo, auto companies have looked to hydrogen fuel cells as a groundbreaking technology: a nonpolluting power source that isn’t constrained by battery capacity and doesn’t require long stretches of downtime for charging. Component costs remain high but have tumbled in recent years. Following Hyundai’s U.S. launch of the Tucson FCEV this spring, the technology will have another big breakthrough moment here this week, when Toyota reveals its strategy for launching a hydrogen-fueled sedan in 2015.

But one key breakthrough — making a hydrogen-fueled vehicle as easy to drive and refuel as a gasoline-powered one — remains elusive. The cars are already here, but without fast and significant progress in expanding the fueling infrastructure and making it convenient to use, they are likely to go nowhere fast.

"At the end of the day, our customers don’t care what’s happening behind the scenes,” said Steve Ellis, fuel cell vehicle marketing manager at American Honda, which has been leasing a hydrogen car called the FCX Clarity in small numbers since 2008. “They just want to be able to pull up to the dispenser, get their fuel and drive off in five minutes with a full tank.

What makes the health of the hydrogen-filling infrastructure so critical is that there is currently no alternative to it. While hydrogen, like gasoline, offers the convenience of refueling in a matter of minutes, there is no other way to refuel a fuel cell vehicle. You can’t fill a plastic gas can with hydrogen and tote it back to a stalled vehicle.

Battery EVs, for all their range limitations, already have a modest infrastructure in place. According to the Energy Department, the U.S. has more than 8,700 public charging stations for battery EVs, and they’re spread across the country.

Tesla Motors’ network of fast-charging “superchargers” on key highway routes aims to provide drivers of its extended-range battery EVs the comfort of knowing they can travel long distances without long recharging breaks.

But even without these special public stations, Tesla owners and other battery EV drivers have a basic safety net: the ability to charge their cars at any common household electrical plug. No such option exists for hydrogen.

Bush and his Hyundai illustrate the challenges of creating a seamless driving experience for operators of fuel cell vehicles. Hyundai unveiled its Tucson FCEV, along with plans to take it to market in Southern California, at last year’s Los Angeles Auto Show, leapfrogging rivals Toyota and Honda, two longtime leaders in fuel cell research. Deliveries began in June. Hyundai’s lease deal, at $2,999 down and $499 per month for 36 months, includes free maintenance and unlimited hydrogen for the life of the lease. Customers enter a PIN at a fueling station and fill up at no charge.

Free fuel might seem like a sweetheart deal to lure customers, but it is actually a reflection of how immature the hydrogen marketplace remains.

Until a few weeks ago, there were no fueling stations in California where a customer could whip out a credit card and pay for fuel. This is partly because hydrogen measuring equipment is not very precise and partly because regulators have been slow to certify stations.

As a result, automakers such as Hyundai have written contracts with each fueling station. They pay a predetermined fee for every car that drives onto the lot, regardless of how much hydrogen a customer pumps. Bush signed the lease knowing that his FCEV will be largely confined to Southern California until more hydrogen stations open in 2015. Imagine a circle around Los Angeles, extending halfway to Las Vegas and one-third of the way to San Francisco. That is how far he can drive for now without passing the point of no return.

So, before setting off for Santa Barbara, Bush dialed the 24-hour hotline that serves as mission control for Hyundai’s hydrogen-car program.

Hyundai’s concierges needed to make sure that Bush’s FCEV, with a rated range of 265 miles between hydrogen fill-ups, wouldn’t encounter any problem that would keep Bush from making the return trip. Stations often go down for repairs. So Hyundai sends its customers text-message updates whenever this happens, Zielomski said.

Employees rushed to find a fueling station along Bush’s route. They found one in Torrance, Calif., across the street from Toyota’s U.S. headquarters.

“It’s like reinventing the wheel, like going back to the first gasoline car. It’s all different,” said Gil Castillo, senior group manager for alternative vehicle strategy at Hyundai. “With all the uncertainties and unknowns, we had to make sure that at every step along the way, if there were questions or issues, the customer would be reassured that ‘Hyundai’s got my back. It’s no problem.’”

Bush, for one, is satisfied with the experience he has had with his Tucson FCEV, but he would like to see fueling become more convenient.

“I’m looking forward to doing less planning in the future,” he said. “As more stations come along, it will get better and better.”

That’s the vision guiding California, which has passed laws mandating the sale of “zero emission” vehicles and has been the most aggressive booster of fuel cell vehicles and hydrogen infrastructure.

California has spent tens of millions of dollars on grants for construction of hydrogen filling stations and expects there to be 51 of them in the state by the end of 2015.

Though they will not be nearly as ubiquitous across the U.S. as gasoline stations, or even Tesla’s proprietary “superchargers,” they will allow Bush to travel to Santa Barbara, San Francisco or even Lake Tahoe, assuming the stations along his route don’t break down or run out of fuel.

The credit-card snafu also should be fixed soon.

Gov. Jerry Brown, a diehard supporter of zero-emissions vehicles, has ordered state agencies to clear the way for hydrogen cars. California’s Department of Food and Agriculture, which is in charge of certifying fueling stations, has started testing hydrogen pumps to make sure they charge customers fairly.

The first station was certified only a few weeks ago. Stations that open in 2015, under the most recent round of state grants, are supposed to take credit cards from day one.

Honda’s Ellis said that by next summer, new building codes will allow dealerships and garages to do any repair job, shy of fixing a hydrogen tank, without building a special hydrogen-safe repair shop. “We’re at that point where we can say, ‘Gee, that’s history,’” he said, referring to the problems that plagued hydrogen infrastructure when he started working with fuel cells, in 2002. “Those are the bloody details of history, and we’re moving on.”

The hydrogen power plant at California State University, Los Angeles, produces hydrogen by zapping water with electricity.

Takeshi Uchiyamada thinks that despite the hurdles, the hydrogen car is an idea whose time has finally come. In the 1990s, tasked with designing a green car of the future, the Toyota executive considered fuel cells — electrochemical reactors that split molecules of hydrogen gas to unleash energy — but concluded they were 15 years away.

Toyota developed the Prius instead. Its name was Latin for “coming before.”

It begs the question: Coming before what?

The answer, from Toyota’s point of view, is fuel cells. The hydrogen-fueled EV that Toyota will unveil this week in Southern California, on the eve of the Los Angeles Auto Show, is expected to be called Mirai, the Japanese word for “future.”

“I personally expect a lot from this hydrogen fuel cell technology,” Uchiyamada, now the chairman of Toyota, said last year during a speech in Washington, D.C., 15 years after the Prius’ U.S. launch.

“Perhaps 15 years from now,” he added, “we can meet again here in Washington and we will know exactly which system has prevailed.”