2010 vs 2011ish (plug-in, lithium)

[Hari_Prius]

get the 2010 and then get hymotion after a couple years as it will be cheaper...

[Mike Dimmick]

Originally Posted by prius2go

Ive heard there is a problem with lithium in that it naturally ages so batteries would need replacing after 3-5 years irrespective of mileage.
Anyone else heard this?
Or is it just laptop and mobile phone batteries.
NiMh dont suffer same

"Aging is a concern with most lithium-ion batteries and many manufacturers remain silent about this issue. Some capacity deterioration is noticeable after one year, whether the battery is in use or not. The battery frequently fails after two or three years. It should be noted that other chemistries also have age-related degenerative effects. This is especially true for nickel-metal-hydride if exposed to high ambient temperatures. At the same time, lithium-ion packs are known to have served for five years in some applications.

"Manufacturers are constantly improving lithium-ion. New and enhanced chemical combinations are introduced every six months or so. With such rapid progress, it is difficult to assess how well the revised battery will age."

-- from Is lithium-ion the ideal battery? on BatteryUniversity.com.

The author is talking about consumer batteries, though, not large-format car applications. We know that Toyota were pretty horrified at Panasonic's failure levels with their standard D-size NiMH cells at the beginning of the Prius project. There's some good stuff in "The Prius That Shook The World".