Battery Pack in Hybrid Is Designed for Life of the Car

"Toyota's own tests have run batteries for the equivalent of 150,000 miles with no discernible degradation, and the company expects them to last the useful life of the car." From this article. "Honda Says Battery Pack in Hybrid Is Designed for Life of the Car." Also, hybrid batteries are recycled:

Is there a recycling plan in place for nickel-metal hydride batteries?

Toyota has a comprehensive battery recycling program in place and has been recycling nickel-metal hydride batteries since the RAV4 Electric Vehicle was introduced in 1998. To ensure that batteries come back to Toyota, each battery has a phone number on it to call for recycling information and dealers are paid a $200 "bounty" for each battery.
Hybrid Batteries: Long Lasting Freshness

I have heard many people express concern over the potential expense associated with replacing a hybrid's battery pack... well, good news from automakers, they are saying that battery packs in their hybrids should last for the life of the vehicle! According to this article, "Toyota's own tests have run batteries for the equivalent of 150,000 miles with no discernible degradation, and the company expects them to last the useful life of the car." An older article was titled "Honda Says Battery Pack in Hybrid Is Designed for Life of the Car."

Honda Says Battery Pack in Hybrid Is Designed for Life of the Car

Think of what a pain it is to replace your car battery when it dies.

Imagine if that battery set you back $ 3,000.

Honda's high-mileage marriage of gas and electric power relies on a nickel metal hydride
battery pack. Boyd acknowledges the Civic's reputation hinges in part on its excellent long-term value. At current prices, Honda would charge out-of-warranty owners about $ 3,000 to replace the 63-pound Panasonic battery hidden behind the rear seat. But Honda is confident its hybrid technology will keep the high-tech Civics humming.

As with other hybrids, the Civic uses energy captured during braking to power up the battery. The battery also charges during coasting.

During my week of driving, the battery meter never dipped as low as half-charged, no matter how hard I drove. But if stressful conditions such as towing or climbing mountain grades drive the battery too low, Honda's Integrated Motor Assist shuts down well before it's fully depleted. In that rare case, or if the car discharges after weeks of sitting in bitterly cold weather, a small auxiliary battery on board can restart the gasoline engine, which then recharges the main battery. concerned with battery life. Thad Malesh, J.D. Power's director of alternative power
technology, said the used-car market will be the key. With Honda expecting to sell modest numbers of hybrids -- 24,000 Civic models this year -- Malesh expects Honda to keep customers happy, even beyond the warranty period.

"When these cars start trickling in, I think Honda will come out with a program to reimburse folks with battery problems whenever they occur," Malesh said. Malesh and Honda expect battery prices to drop, perhaps dramatically, by the time owners need them. The automaker recently signed a joint deal with Sanyo to research battery technology.
Check out my other guide internal combustion engine OR History Hybrid Car