There's been some confusion over the past year or so about the relative merits of driving a hybrid car, in terms of how beneficial it is for the environment. Some detractors have said that the batteries in the car will end up filling landfills anyway, negating all of the positive attributes of the hybrid (or all-electric, as more vehicles hit the roads) powertrain. A Slashdot poster recently asked if there's any merit to that idea.

Here's some data quoted from HybridCars.com, which the first commenter highlighted:

"The hybrid battery packs are designed to last for the lifetime of the vehicle, somewhere between 150,000 and 200,000 miles, probably a whole lot longer. The warranty covers the batteries for between eight and ten years, depending on the carmaker.

"Battery toxicity is a concern, although today's hybrids use NiMH batteries, not the environmentally problematic rechargeable nickel cadmium. 'Nickel metal hydride batteries are benign. They can be fully recycled,' says Ron Cogan, editor of the Green Car Journal. Toyota and Honda say that they will recycle dead batteries and that disposal will pose no toxic hazards. Toyota puts a phone number on each battery, and they pay a $200 'bounty' for each battery to help ensure that it will be properly recycled.

"There's no definitive word on replacement costs because they are almost never replaced. According to Toyota, since the Prius first went on sale in 2000, they have not replaced a single battery for wear and tear."

That matches up with what I keep hearing, but I'd still be interested to find more sources verifying the above claims—anyone? (And please check out the full discussion—lots of interesting comments.)