Hi, get something nice and caffeinated and get comfy...
As far as the nickel metal hydride (NiMH) battery goes, the current record for a Prius is over 360,000 miles with the original NiMH battery and hybrid drive train. Prius are regularly used for taxis and government use (see New York and the state of Colorado).
I have spoken with owners of independent auto shops who regularly see Prius with 100,000-200,000 and up to over 350,000 miles coming in for routine service work with no issues.
As far as replacing the batteries in 100,000 miles, Toyota has never had a customer pay to replace a NiMH battery in any of their hybrids ever. That is for Prius, Camry Hybrids or Highlander Hybrids. The Prius have been in the US since 2000, seven years.
There have been NiMH batteries replaced because of accidents or owner damage or neglect (wiring in a big stereo, for example), but no one has ever had to pay otherwise.
BTW, as far as the "$5000-10,000" for a new NiMH battery goes, that is completely false. Call your local Toyota dealer and ask for the parts department.
New NiMH batteries for either the first or the second generation Prius run $2985.13.
These are not typos and anything you may have seen to the contrary is an urban myth.
All of my service and parts amounts come from a local Toyota dealership, and do not figure in any kind of promotions, coupons, or discounts. I called on 6/12/07.
Also, there is an 800 number on each NiMH battery (the one that provides the energy to move the Prius, Camry, or Highlander Hybrids) and that number allows a person to turn in that battery for a $200.00 bounty.
The entire battery, just like almost every little bit of those vehicles, is completely recyclable.
The NiMH batteries that people use in power tools and throw out use a different type of control system and charger than what is in vehicles like the Prius. The Hybrid Synergy Drive unit that Toyota developed is designed to keep the NiMH battery in a mid-peak charge range, trying not to top-charge it or, of course, completely discharge it.
That enables a vehicle NiMH to last fairly indefinitely. Obviously, there will be some breakdown eventually, but one of the great things about the Prius system, for example, is the NiMH battery is composed of 36 individual cells. If one cell goes bad, it can be replaced and the remainder stay. That is what's happened when Toyota has torture tested the Prius in Alaska and Death Valley.
The government has tested Prius batteries and found that there was a 10% reduction in power output at 100,000 miles. That means there was still 90% usable capacity at the point where the myths say the NiMH batteries are used up.
As far as the energy and materials for the NiMH batteries go:
The plant in Sudbury where Toyota buys approximately 1.5% of the plant's annual nickel output can be seen using this Google maps address:
Sudbury, Ontario is called the mining capital of the world for good reason.
The Sudbury plant has been in continuous operation since the rock was blasted to make way for the Canadian Pacific Railway in 1883.
That means that nickel has been mined there for the last 124 years. The Prius has been on the road since 1999. What about all the environmental damage done for the 116 years before the Prius ever came along?
There used to be a great deal of pollution at the Sudbury plant, just like there was at a lot of factory facilities. However, new pollution controls are in place and Sudbury residents themselves will talk about how things are improving dramatically in the area around the plant. Young trees are growing there, even now.
Another thing noted about the area around the plant is the Apollo astronauts trained there. It has been said that the area around the plant was as lifeless a wasteland as the moon. Actually, the astronauts trained there because the rock formations were similar to those on the moon. This area of Ontario was hit by a meteorite which created a basin and caused much of the look of the area. The moonscape feeling is also from the slag heaps from smelter output. Anyone who has ever seen any factory facility knows there is always a large amount of material left over from the original raw materials, be that a nickel plant, a steel smelter, or a dog food producer.
Also the environmental damage is not all due to the nickel plant - there is other industry, and a lot of the trees disappeared due to extensive logging.
Take a look for yourself. Here's a breakdown:
The Sudbury nickel plant produces around 60,000 tons of nickel per year. If Toyota buys 1000 tons/year, that's around 6% of the total output.
I have personally presented a Prius battery to local safety responders and fire department personnel. The entire pack weighs 117.47 pounds, which is the components as well as the actual nickel itself. The nickel weighs about 50 pounds. So that's 50lb per Prius, with 2000 pounds per ton, that's 40 Prius per ton of nickel.
Considering the plant puts out 120,000,000 pounds of nickel each year, each Prius uses about 0.000024 of the annual production of the Sudbury plant.
Please let me know if my math is off anywhere, and I'll be glad to make corrections.
And that's about it. No surprises and the maintenance is pretty simple.
There have been too many hybrids bought, and there have been too many miles put on them, for this to still be a fluke or fringe type of vehicle. You would have heard real news if they were a bad idea, not just the urban myths that float around.
Thanks for reading this far.