It was the year that defined a cultural revolution: 1969.

It was also the year an international cadre of researchers and academics got together to exchange the technical information needed to bring about a transportation rebellion where people would leave the oil pump behind and plug in with electric vehicles.

What was once a meeting for intellectual visionaries has now expanded into a full-fledged conference. On Sunday, doors opened to the four-day long International Electric Vehicle Symposium and Exposition in Anaheim, Calif., where researchers, companies, government agencies and financial backers are planning the next stage of the revolt.

That next stage appears to be focused on batteries, which are key to getting better mileage out of hybrids and better range out of all-electric vehicles.

Lithium-ion batteries, often found in consumer electronics like cell phones, have caught the interest of the electric-vehicle community because they are potentially more powerful, for their size, than other car batteries. But they are expensive and also have the problem of "thermal runaway" – overheating and even catching fire.

A number of scientists and entrepreneurs have been researching different ways to get around the battery issues.

Companies such as Valence Technology, Toyota and even ExxonMobil were planning to bring battery-related technology to the event.

Rechargeable-battery company Valence Technology (NSDQ: VLNC) said Friday it planned to unveil its latest phosphate-based lithium-ion battery, dubbed Epoch. With phosphate to keep it from catching fire, the battery also is equipped with an advanced management system that monitors and enhances cell performance.

The battery packs will be available in 12.8-volt and 19.2-volt modules, and the Austin, Texas-based company said it hopes the batteries will be powering electric-vehicle fleets in Europe next year.

Oil giant ExxonMobil (NYSE: XOM) planned to present its lithium-ion battery-related technology at the conference.

ExxonMobil and its Japanese affiliate, Tonen Chemical, have developed a separator-film technology for the batteries. Separator film keeps the battery’s positive and negative fields from touching.

According to ExxonMobil, the company’s film can handle higher heat levels.

Conference attendees won’t just be talking, either. Some will be able to view or even drive a variety of alternative vehicles, including hybrids, plug-in hybrids and fuel-cell electric vehicles.

Among the showcased cars is Toyota’s Prius plug-in hybrid prototype. Earlier this month, Toyota said it was going to study U.S. consumer demand for the car, among other need-to-know items like the car’s mileage.

The company has set no date as to when consumers will be able to buy the car, which takes three hours to charge on the same voltage used by household appliances such as refrigerators.

Toyota still has some key issues to figure out before it brings the car to market, particularly the batteries.

Knight said the battery pack is the most important thing when it comes to greater electric driving range. "We are still researching the ideal battery pack," said Cindy Knight, a Toyota spokesperson. "It can’t overheat and burst into flames."

While most companies -- Toyota included -- want the range that lithium-ions can bring, the plug-in hybrids being pilot tested use nickel-metal-hydride batteries instead.

Some plug-in hybrid advocates, such as Felix Kramer, founder of CalCars, supported the move, saying it’s important to have "good enough" plug-in hybrids now instead of waiting for lithium-ion technology to be perfected for the automotive market.

Not everyone agrees the plug-in hybrids are worth the effort, however.

In October, Honda Motor CEO Takeo Fukui said plug-in hybrids offer too few environmental benefits for the company to pursue.

If the company were able to come up with lithium-ion batteries that were cheap, safe and high-performing enough for plug-in hybrids, Honda would rather use the batteries for electric vehicles, he said (see Honda Says No to Plug-In Hybrids).

Analysts say electric cars aren’t ready for mass adoption because they can’t drive as far on a single charge as gasoline cars can drive on a single tank.

Companies with new lithium-ion technologies hope to change that.

Aside from the companies mentioned above, Project Better Place in October raised $200 million for a plan to lease removable batteries for electric cars, and A123Systems grabbed $30 million for its high-efficiency lithium-ion batteries for hybrid and electric cars (see Startup Snags $200M for Electric-Vehicle Battery Leasing Program, A123Systems Gets $30M Charge).

But although the interest in electric cars and plug-in hybrids is growing, it’s clear there is still plenty of work ahead.