Porsche has announced that it will make a production version of its 918 Spyder plug-in hybrid concept car.

The car, which was first shown off this year at the Geneva Auto Show, can accelerate to 60 miles per hour in under 3.2 seconds, and reach a top speed of 198 miles per hour. It pairs an electric motor with an eight-cylinder engine. Drivers will be able to putter along for 16 miles using electricity alone. In ordinary hybrid mode, the car can get 94 miles per imperial gallon (about 78 mpg). For the highest performance, select Sport Hybrid or Race Hybrid mode. The latter includes a "push-to-pass" button that delivers a surge of power from the battery.

With Porsche getting in on the electric-powered action, one wonders how up-starts like Fisker and Tesla will manage.

When a battery company unveils new technology and brags about its long lifetime, the best industry analysts aren't necessarily impressed by charts showing voltage-current curves over hundreds or thousands of discharge cycles. "Show me the warranty," they say. That's a good indication of how long the company really thinks the battery will last.

GM executives have said they expect the battery for its upcoming Volt electric vehicle (actually, a type of plug-in hybrid) will last the life of the car. Now GM has backed up those claims (sort of) by announcing a 8-year, 100,000 mile battery warranty. That's not quite as long as I'd like a car to last--and not as good as a 10-year warranty some had expected--but it's a good amount of time compared to the 3-year warranty offered by some other manufacturers. Nissan, which is coming out with the electric Leaf this year, hasn't yet announced warranty details.

The battery warranty is key, since replacing a full battery pack could cost more than $10,000 by some estimates.

One of the key selling points used by supporters of battery-powered electric vehicles, as opposed to say, hydrogen fuel cell vehicles, is that the infrastructure for delivering electricity already exists. This argument is a little misleading, though. Sure, there are outlets all over the place (although not along the street for apartment dwellers--but let's leave that aside for now). But if you want to use the full range of your electric car, it could take over a day to recharge using a standard 110-volt power outlet.

The point was driven home Monday in an article in The Wall Street Journal, which described Nissan's efforts to break through bureaucracy to make it easier for homeowners to get special electric vehicle charging stations installed. Nissan, which is coming out with an electric vehicle this year called the Leaf, is concerned that customers will be put off from buying the car by the 20 hours required to recharge it from a standard outlet to get its full 100-mile range. Currently, it can take weeks for cities to issue the necessary permits for a fast charger that can cut recharging time to eight hours, the article said, and the price for the special charger, including installation, will range from about $1,200 (with a tax credit) to several thousand dollars if a electric panel upgrade is needed.

Tesla Motors, the small automaker that went public last month to much fanfare, advertises a less than four-hour charging time for its Roadster, even though the car has a much longer range than the Leaf--245 miles per charge. But that's with a special "Home Connector" that costs about $2,000. Also, depending on the amperage of the circuit, charging could take up to six hours. Using a standard outlet for a full charge will require 37 to 48 hours, depending on whether it's connected to a 15 or 20 amp circuit. The good news is Tesla will sell a kit ($1,500) with a wide variety of adapters that will allow enterprising car owners to plug into a motel's air conditioner outlet (14.5 hours for a full charge), a dryer outlet (10 hours) or, if one is handy, an outlet for an electrical welder or RV (six hours).

The Chevrolet Volt, a plug-in hybrid coming out this year, only takes 10 hours to fully recharge with a standard outlet, but that's because it only has an electric range of 40 miles.

Most people actually won't need to use more than 40 miles of electric range in a day--that's less than the average daily drive in the United States. But potential electric car buyers may flinch knowing that they'll have to keep their car plugged in every moment it's not being driven in order to access the full range--or go through the hassle and expense of installing a special charger. This won't stop early adopters, but it could put off mainstream acceptance. So it could take even longer for them to catch on than hybrid vehicles, which after a decade still account for less than 3 percent of new car sales in the United States. Cities that want to promote electric vehicles should work with dealers to make installing fast-chargers both fast and cheap.