NEW YORK ( TheStreet) -- Last week I gave a keynote presentation at Batteries 2012, an important global conference for developers and manufacturers of "advanced technology batteries" including nickel cadmium, nickel metal hydride and lithium-ion chemistries.The mood was not what I'd call ebullient. In fact, it was downright grim as battery developers and manufacturers come to grips with the cruel reality that electric cars, at least those with plugs, don't have any significant market appeal today and they probably won't be adopted at significant scale for at least a decade despite heroic efforts from governments, automakers and advocacy groups of every stripe. The reason is simple: The economics of using expensive batteries to replace a cheap fuel tank for the dubious luxury of using coal and natural gas as transportation fuel simply don't work for the majority of consumers who expect to recover the premium cost of advanced vehicle technology in their first four years of ownership. In his presentation, Ted Miller of Ford showed how stabilized gasoline prices needed to be $5.25 a gallon before an HEV (hybrid electric vehicle) could satisfy a four-year payback expectation and $7 a gallon before diesel could make the grade. He didn't bother including cars with plugs in his payback graph because they can't recover their cost premium in four years unless stabilized gas prices are well over $12.50 a gallon. A more intriguing presentation from Akihito Tanke of Toyota summarized the results of a 200-unit plug-in Prius demonstration in Europe that focused on user behavior rather than technical potential. The demonstration showed that the 23 km electric-only range of the plug-in Prius was adequate for about 65% of trips, but user behavior was the critical factor in overall fuel economy. In the demonstration, 25% of users plugged in their cars between 3.5 and 7 times a week, 32% plugged in their cars more than 7 times a week, and 43% plugged in their cars fewer than 3.5 times a week, for an overall average of 0.9 times per day. In comparison, users in Japan's Toyota City plug in their cars an average of 2.1 times per day. So while Japanese drivers use an average 2.23 liters of gasoline per 100 km (103 mpg), the demonstration project drivers used an average of 4.33 liters per 100 km (54 mpg). To put those figures into perspective, Toyota advertises an average fuel consumption of 3.9 liters per 100 km (60 mpg) for the newest plug-free Prius. I guess there's some merit to the theory that it works better if you plug it in. The most interesting evolutionary difference between the presentations I watched this year and those common a few years ago was the classification of HEVs. In the days of heady plug-in exuberance, HEVs were lumped in with internal combustion engines and the gee-whiz growth graphs focused solely on cars with plugs. Today, most presenters include HEVs in the electric drive category to camouflage the dismal market outlook for plug-ins. While most graphs still predict electric drive penetration rates of 6% to 10% by 2020, only a small fraction of those cars will have plugs, and the global battery market will continue to be dominated by lead-acid chemistry, just as it has been for decades.