Originally Posted by theaveng
I disagree. My mom's 20-year-old car showed no degradation while it was sitting in the garage. It was driven once a week, and had its oil changed once a year, but that was basically it. Still ran like new.
I don't think we're in disagreement. Time is a factor for many things on automobile; a good example is the 12V battery, though obviously this is seen as a minor repair compared to the hybrid battery. Time alone can affect plastic/rubber seals, suspension components, belts, hoses etc just as much as actually being driven, depending on the storage conditions.
My overall point was that if you put an Insight in storage, it would deteriorate at the same rate as the "normal" car - except the IMA battery, since the normal car doesn't have one. I guess I'm easily able to differentiate the IMA battery from the rest of the car; the car would still run and drive great - it just may need a new IMA battery.
Toyota did a really good job with their Prius battery. Consumer Reports did a test on one that was ten years old/210,000 miles, and they found no degradation in its NiMH batteries. At least none that could be detected via 0-60 and 1/4 mile testing. And the city fuel economy, which uses a lot of battery power, measured the same. The ten year old Prius acted as well as a brand new Prius they tested a decade earlier. My insight would not perform as well (it drains to empty in about half-a-mile of city driving; the battery is only six years old and shot).
The Prius battery is made by Panasonic, AFAIK
The prismatic cells used in the Prius do seem more robust than the cells used in the Insight. Hopefully our newer cells can give them a run for their money.
However, the difference isn't the cells alone; the control systems factor as well. The Toyota system only uses 40% of the batteries capacity(40% - 80%), while as we know the Honda system uses 60%(20-80%). That alone could result in some significant cycle life improvements.
Anyway, the statement you quoted is a fact, but don't take it out of context. Obviously whether a battery is used or not has a profound effect on its overall life. A recent whitepaper I read on the use of NiMH batteries in the telecom industry reports a maximum theoretical life of around 30 years.
Keep in mind that the original NiMH cells used in the Insight were manufactured using old technology(~1998 ). NiMH technology has advanced since then, which is why we're able to deliver a battery with lower internal resistance and higher capacity at higher maximum charge and discharge rates. We're using technology developed circa 2008, so theoretically we will see more improvement by 2020; perhaps 10Ahwill be possible in a standard "D" case by then.