The U.S. Needs More Than a Pot of gold at the end of a rainbow to conquer the next technological challenge, say critics of a proposed battery bounty.

The research tab for a superior next-generation battery for hybrid-electric vehicles will far exceed the $300 million prize put forward by presumptive Republican presidential nominee John McCain, leading consultants say, adding incentive money is better spent up front.

Additional funds must be set aside to promote the production of lithium, a core ingredient of the batteries expected to succeed the nickel-metal-hydride cells used in today's HEVs. OEMs such as General Motors Corp. and Toyota Motor Corp. are banking on lithium-ion batteries to power a promised fleet of plug-in hybrids.

“We don't want to trade our foreign dependence on oil for a foreign dependence on batteries,” warns Lisa Walsh, principal of Washington-based expert services advisory firm LECG.

McCain proposed the bounty recently.

“In the quest for alternatives to oil, our government has thrown around enough money subsidizing special interests and excusing failure,” McCain told a crowd at Fresno State University. “From now on, we will encourage heroic efforts in engineering, and we will reward the greatest successes.”

If the competition is winner-take-all, don't expect the desired results, says Don Hillebrand, director of the Chicago-based Argonne National Laboratory's transportation research center.

“The devil's in the details,” Hillebrand says.