So far, my wifes' Corola has gone 185k without a repair. The problem with battery packs so far is you are pretty much guaranteeing a 8-10k repair every 5-7 years. Essentially, you are making the whole vehicle a disposable product which does not sound very green to me.
It's a valid point to be concerned about, battery replacement cost is one of the biggest hurdles car companies will need to overcome if this is to work in the long term. Your 8-10K is low compared to other studies done. Carnegie Mellon did a study and estimated that the Volt's battery pack alone, planned with a capacity of some 16 kWh, would cost $16,000, which would be $1,000 per kilowatt-hour. GM disputes this figure and says that the cost is no way near $1,000 dollar per kilowatt-hour, but they didn't give exact figures. If the price difference between the cruze and volt listed in the original post are accurate I would guess the cost is somewhere around 700-800 dollars per kilowatt-hour, which would mean 12,000 to replace the pack. In the long run I don't think 8-12k replacement cost will remain, and the price will eventually begin to drop as economy of scales kick in. A new market will most likely also emerge for recycling batteries to help lower costs. GM will most likely need to offer 10 year warranties to early adopters to cover battery costs if they plan on selling any.
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speaking of batteries this article just came out...
http://gm-volt.com/2009/03/11/100-fold-lithium-ion-battery-breakthrough/#comment-99914The scientists were able to develop a new formulation of lithium iron phosphate that allows for extremely rapid charging, and massive specific power.
The authors note that this new ability to charge and discharge lithium-ion batteries within seconds blurs the distinction between batteries and ultracapacitors, and may result in radical lifestyle change in terms of consumer electronic devices and plug-in cars
The authors note that if electric grid power was available, an electric car with a 15kWh battery could be charged in 5 minutes. This would require the delivery of 180 kw of energy in that time frame. Further those cars could have extremely powerful acceleration and be useful in other power applications such as towing