Why can't you just charge the NiMH batteries?

[ZTrekus]

Everytime they talk about a plug-in prius, they always talk about Lithiom Ion Batteries which the 2010 doesn't have.

But what is wrong with simply charging up the NiMH that is in there? - At least one coule have a full tank (so to speak) of battery power before leaving home. Isn't that simple enough and worth it?

[Midpack]

Originally Posted by ZTrekus

Everytime they talk about a plug-in prius, they always talk about Lithiom Ion Batteries which the 2010 doesn't have.

But what is wrong with simply charging up the NiMH that is in there? - At least one coule have a full tank (so to speak) of battery power before leaving home. Isn't that simple enough and worth it?

You could, but the existing battery is way too small for dedicated EV service. Projections I've seen suggest you'd have a range of 1 mile to 10 miles. That's one of the reasons the PHEV Pruis is estimated at $48K - way more battery!

[Mike Dimmick]

Originally Posted by ZTrekus

Everytime they talk about a plug-in prius, they always talk about Lithiom Ion Batteries which the 2010 doesn't have.

But what is wrong with simply charging up the NiMH that is in there? - At least one coule have a full tank (so to speak) of battery power before leaving home. Isn't that simple enough and worth it?

Yes, it's simple. No, it's not worth it. EV range is only about a mile. Prius is designed as a charge-sustaining hybrid and usually has six bars of charge when you park it. That doesn't leave a lot of space to put more energy in. Likewise it doesn't really want to deplete the battery that far - it will only drop to two bars in EV mode.

It's the capacity of the battery that's the issue, not the chemistry. NiMH is perfectly capable, albeit it might be a little heavier, but it should be cheaper. The problem is that Chevron hold (through subsidiaries) patents on large NiMH batteries, and they won't license them.