FORTUNE -- Automakers are operating in terra incognita as they prepare for the biggest change in the way cars are powered in a century. As they begin to add battery-powered cars to their lineups, they will have to solve some fundamental problems about how the cars are built and sold.
For engineers, the questions include:
For marketers, the issues are:
There are few guideposts to follow. The only equivalent parallel in recent history has been the launch of the hybrid gas-electric vehicle, where, arguably, only one company has been successful.
That is Toyota (TM), which unlike most other manufacturers, built a hybrid-specific car, the Prius. The car's unique character attracted early adopters as well as the environmentally-conscious who wanted to visibly demonstrate their commitment, and Toyota promoted it effectively.
Honda tried to drive the same road with its own hybrid, the Insight. But both the first- and second-generation vehicles sold poorly.
Other automakers installed their gas-electric powertrains in existing models, essentially making the hybrid device an option. The cars lacked a distinctive identity, most have suffered weak sales.
If there lessons to be learned from Prius, they haven't been reflected in current battery-electric strategies, no two of which seem to be alike.
Two French automakers, for instance, are using sharply different approaches.
PSA is limiting its risks. It will launch its first electric vehicle a year from now under both its brands, Citroen and Peugeot. But while it is marketing the cars under unique names, Citroen C-Zero and Peugeot Ion, the cars themselves are being outsourced; they will be produced by Japan's Mitsubishi Motors. The planned volumes will be low, 20,000 units per year; and the price will be high, about $44,000 before government incentives.
By comparison, Renault has jumped into the market with both feet. It expects to sell 200,000 units a year of its electric car, the Fluence Z.E. (for zero emission), which it developed with its corporate partner, Nissan, and its price reflects those aspirations. The car alone will sell for about $20,000; the battery will be leased separately.
A similar split exists in the U.S. Determined to flex its technological muscles, General Motors has devised a unique battery-gas engine powertrain, inserted it into a new body, and given the resulting vehicle a distinctive new name: the Chevrolet Volt.
Ford (F, Fortune 500) is taking a more conservative approach. Rather than make a unique electric vehicle, Ford plans to make battery propulsion systems an option on its top-selling cars. That way, it argues, it can make a variety of powertrains -- full electric, gas-electric hybrid, diesel, or standard gasoline -- on the same assembly line. In theory, the variety protects Ford against swings in market preference -- or having a single vehicle singled out as a market flop.
Another key question revolves around batteries: Develop and manufacture your own or buy them from a supplier? GM is making its own batteries, as is Daimler, which is forthright about its belief in the strategic necessity of proprietary battery technology. It believes that since batteries are essential to the functionality of electric vehicles and central to their operation, good ones can provide an enormous competitive advantage.
Other companies don't want to make their own batteries and prefer to buy them. For a company like BMW, producing its own batteries doesn't make economic sense. Volkswagen has the necessary scale but isn't fully committed to electric power.
Two of the biggest bets on electrics for the U.S. market are being placed with radically different strategies.
Tiny Tesla (TSLA) makes only electric cars and is focused on the market's high end. Now that it has put more than 1,000 fully-electric Roadsters on the road for $100,000 plus, it is developing a sedan, the Model S. The car is expected to sell for $57,400 and begin deliveries in 2012, with production aimed at 15,000 cars a year.
Nissan is targeting higher volume with a less expensive car. It launches the five-passenger Leaf, powered by Nissan's own batteries, later this year, priced at $32,700 in the U.S. It hopes to sell 50,000 cars worldwide the first year, and it has production capacity to build several hundred thousand. The Leaf will account for only a fraction of Nissan's car and truck production, but its success or failure will weigh heavily on the company's reputation.
As to which company has the right combination of capital investment, technology, branding, and distribution, only the marketplace can decide who has invented the next Model T -- and who has given birth to another Edsel.