NiMH Batteries

They sued them for using the large format prismatic NiMh cells. The small NiMh cells have always avoided the patent. The 6.5Ah prismatic NiMh cells that Toyota is using on their Prius, and all of their other Toyota and Lexus hybrids was done with a contractual agreement between Panasonic(the maker of those cells) and Toyota. This is why they aren't on other hybrids such as the Honda and Ford hybrids. Honda is using 6.5Ah Panasonic cylindrical NiMh cells and Ford is using 5.5Ah NiMh cylindrical cells(not sure who manufacturers for Ford), although Ford might have something different on their Fusion but I know the Ford Escape hybrid is 250 cylindrical cells in series.

Now we have OEMs GM, Ford, and Hyundai/Kia going for LG Chem as their manufacturer of Lithium Manganese Spinel cells. GM spent a long time testing different manufacturers cells too. I think we are better off with lithium, it's getting much cheaper as time goes on and NiMh is actually more expensive. Cycle life seems to have gotten much better, the internal resistance is much better with lithium(except maybe against the cheapest LiFePO4), power and energy density are much better and I'm not sure if NiMh could compete. As far as an OEM standpoint, I doubt anyone would go for it anymore and so there really isn't a market. I think SAFT has been producing some large format NiCd and NiMh still but it's expensive and I don't think it's easy to get. There is a car(probably a few) on EV Album using them.

Hi Notailpipe

If they made a slight chemistry change and repatented
the new patent would only apply to the new chemistry and the old chemistry would then be public domain for anybody to use.

If nobody has taken it up that means either;
It wasn't that good after all
It has slipped under the radar and nobody has noticed it
Lithium has been found to be better

Off topic - still havn't found Colorado - are you sure its somewhere here in Godzone?

Duncan said:

Hi Notailpipe

Off topic - still havn't found Colorado - are you sure its somewhere here in Godzone?

Click to expand...

Hi Duncan. You're not gonna get me to change my location, haha. I've heard of you kiwis, how come you haven't heard of beautiful Colorado? Some of the most breathtaking sights in the U.S. (<-- there's a hint for you where to start looking)

... back to topic. Actually, I know with drug patents when the patent expires they can usually get the mirror-image isomer patented, at which case the old one becomes a generic and the new one often is souped up with marketing, not necessarily better. I think when they repatented Li-Ions, they had meanwhile come up with advances in battery terminal metallurgy, for example, that you wouldn't want to use the old one, patents or not, cause it's so much better with the other ones. So maybe the original Li-Ions are teh suck relative to other things out there now.