Mounting regulatory pressures spearheaded by the State of California could push automakers to spend billions of dollars more on fuel cell electric vehicles, and perhaps gravitate away from the battery-powered cars helping them achieve compliance today.

“That’s one way of playing the game of credits,” Fiat Chrysler powertrain chief Bob Lee tells WardsAuto. “I’m pretty sure everyone is looking at (FCVs).”

Automakers such as FCA use battery-electric cars to achieve tailpipe emissions compliance in California, and OEMs can use a portion of those credits toward meeting emissions laws in other states that have adopted similar standards tougher than federal rules.

But in 2017, California’s emissions regulations will change and FCVs, not BEVs, will carry the so-called “traveling credits” automakers use to remain compliant. It could lead to a shift in automaker investment away from batteries to fuel cells.

FCA officials say FCV technology is “on their radar,” but the automaker does not appear entirely committed.

Lee told journalists and Wall Street analysts at the company’s annual investor day earlier this year the technology remains commercially unviable despite California’s tightening regulations, which call for 15% of an automaker’s sales in 2025 to be a zero-emissions vehicle.

Volkswagen takes a similar view.

VW rolled out the Golf Sportwagen Hymotion FCV concept at the Los Angeles auto show last week, but like the Audi A7 Sportback h-tron FCV also breaking cover there it will not see daylight until buyers and a fueling infrastructure are in place.

“But when there’s demand, all we have to do is throw the switch,” says Heinz-Jakub Neusser, head of product development at VW.

Other automakers, however, have doubled down on fuel cells in recent months.

Ford, Daimler and Renault-Nissan are working together on FCVs, while Toyota and BMW have tied up on development. At the Los Angeles auto show, Toyota revealed the Mirai FCV it plans to sell and lease in California late next year. The Japanese automaker’s new interest in FCVs, coupled with a wind-down of its partnership with BEV maker Tesla, signals a clear break from the battery-propulsion strategy it had been pursuing.

“The longer-term intention is to sell fuel cells for a long time, expand it out of California as the infrastructure grows,” Bill Fay, group vice president-Toyota Div., tells WardsAuto.

General Motors and Honda, two long-time FCV researchers, most recently announced collaboration on a long-term program to develop hydrogen-fuel-cell systems and storage units with the goal of bringing the technology to market, originally targeting the 2020 timeframe.

But Honda announced earlier this month it will start selling a new FCV to replace the FCX Clarity next year in Japan, and sales of the vehicle in Europe and the U.S. will follow on a timetable the automaker has not disclosed. The agreement with GM called for the Detroit automaker to bring an FCV to the U.S. market after Honda.