Hybrid critics have long said that the cost of a new battery, if it failed after the car's warranty expired, would quickly wipe out an owner's years of savings on gasoline.

The argument was not unreasonable, given the high (and at first, uncertain) cost of the battery packs, which had yet to prove their durability in real-world driving.

That situation has changed since hybrids went on sale in the United States a decade ago, according to The New York Times.

Both Honda and Toyota, the market leaders, now have considerable hybrid experience. And both have recently reduced the prices of replacement nickel-metal-hydride battery packs -- a move made possible by maturing technology and growing sales volumes, they say.

Even so, new replacement batteries still cost more than $2,000.