I respectfully disagree. The batteries will eventually fail- no batttery system has an infinite number of charge/discharge cycles. And that works against the long-term cost effectiveness of Hybrids. Assuming the political/PR climate allows, my employer plans to trade or scrap ours before the battery packs have to be replaced.
my understanding is, the current Prius has battery
storage of about one kilowatt-hour.
However, the 'brain' of the car only uses 30 percent of that.... the 'state of charge' is always between
50% and 80%, the best for battery life.
I am not saying that the battery life is infinite,
but batt life is way more that could be used,
I mean, how many battery-assisted 0 to 60 MPH
acceleration cycles will the car do in its life,
well , the batt can handle that many,
in part because the electrical assist is
not all that much.