1.Road map to better cars

2.Fuel sell

3.Whither battery cars?

4.Big bad batteries

5.Yearning for electric cars

6.A cheaper way?

Storing Juice
The problem with batteries is simple to state, and gnarly to solve: They simply can't store much energy, compared to ol' familiar gasoline. While one kilogram of regular gas stores 11,860 watt-hours of energy, a lead-acid battery storing 44 watt-hours is considered advanced.

That simple calculus worries the experts. "It is doubtful that electric cars will ever enjoy the range or performance advantages to which auto users have become accustomed with petroleum-fueled engines," says Art MacCarley, a professor of electrical engineering at California Polytechnic State University in San Luis Obispo.

Although any comparison of power sources must note that battery cars use energy about three times as efficiently as gasoline cars, storage is the biggest obstacle facing battery vehicles.

MacCarley says, "Since the time of the first electric automobiles in the late 1800s, a large number of new batteries have been demonstrated" capable of storing as much as 20 times the energy density of the lead-acid models. "Some hold substantial promise for replacing the lead-acid battery, but cost remains a key obstacle."

Batteries are categorized by two key components: the electrolyte -- a chemical that conducts electricity -- and the electrode -- an electrical conductor through which an electric current enters or leaves an electrolyte or other medium.

In a battery, the two components interact to produce a flow of electrons. In lead-acid batteries, the electrolyte is acid, and the electrodes are lead. Some exotic batteries use air to oxidize a metal electrode. Other can be recharged simply by dumping and replacing the fluid -- much as gasoline cars are "recharged" by adding fuel (see "All Charged Up..." in the bibliography). But most exotic batteries are simply too expensive for production cars, and some operate at hundreds of degrees Celsius.

What good are electric vehicles, anyway?