# NiMH Batteries



## brandon0409 (Sep 26, 2008)

I was reading an article on EVWorld.com
http://www.evworld.com/article.cfm?storyid=1532

Stating that this car 10 or more years ago used NiMH batteries and drove 250 miles while using only 15% of its power.

Are NiMH batteries available now? And if so are they comparably priced to Lead/Acid batteries or more to Li-ion ones?

And where can you buy them if they are available?
Thanks


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## judebert (Apr 16, 2008)

NiMH batteries were most famously used in the Toyota Rav4EV. It could go more 100 miles on its pack, even after 100,000 miles of use.

As I recall,l they never let the batteries drop below 50%. If you could override their electronics, you should've been able to get 200 miles out of it. 

However, Ovonics owns the patent for NiMH batteries, and the majority share of Ovonics is owned by Texaco. (Or is it BP now? I can never remember.) In any case, they don't allow anything bigger than 3Ah to be produced. 

Why? Draw your own conclusions. The company says they have too many concerns over continued development and product marketing to support anyone making the cells in large format.

In any case: no, you can't have NiMH. Not for you. Or any of us, either.


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## gmijackso (Sep 30, 2008)

According to wikipedia (so it MUST be true) the NIMH batteries used were GM/Ovonic Nickel metal hydride batteries, 24 of them at 12V 90ah. The car is apparently being created as a kit car here: http://www.sunrise-ev.com/ . The problem I have, is that in their specs, they're planning on using lead acid in their kit. 

So does that imply that the nimh claim is inaccurate, or that it wasn't as effective as thought, or too expensive, or are the new guys just cheaping out? I dunno, interesting though to say the least.


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## Guest (Oct 24, 2008)

The Sunrise Project is just that, a project. The Sunrise was built by Solectra and this guy purchased a Sunrise and is duplicating it for a future production EV vehicle. Solectra dumped the Sunrise. The original used the NiMH batteries like the Rav-4 and the EV-1. However since GM purchased the leading share in Ovonic's NiMH battery and then sold out to Texaco/Chevron. They decided to sit on the battery and did not even let Ovonic advertise with out permission. It was effectively squashed and remains so today. Nope they will use lead for the new Sunrise until Lithium or new NiHM batteries become available at a fair market price. Till then lead leads the way. Wooo Hoooo. 




gmijackso said:


> According to wikipedia (so it MUST be true) the NIMH batteries used were GM/Ovonic Nickel metal hydride batteries, 24 of them at 12V 90ah. The car is apparently being created as a kit car here: http://www.sunrise-ev.com/ . The problem I have, is that in their specs, they're planning on using lead acid in their kit.
> 
> So does that imply that the nimh claim is inaccurate, or that it wasn't as effective as thought, or too expensive, or are the new guys just cheaping out? I dunno, interesting though to say the least.


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## gmijackso (Sep 30, 2008)

Yeah, I figured the basics of that when I read Judeberts post. They posted as I was writing my post apparently. 

The AH cap on NiMH was something new to me. Weird the things you learn in the course of a day.


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## brandon0409 (Sep 26, 2008)

So (if available) would NiMH batteries be more efficiant than Li-Ion batteries?

It sounds like (from previous posts I've read) that Li-Ion's only get about 40- 70 miles on a charge, when NiMH's can get around 100 or more.

Is this thinking flawed


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## judebert (Apr 16, 2008)

"This guy", incidentally, is Lee Hart: one of the most respected members of the EV Discussion List. His history in EV development and conversion is impeccable. The Sunrise is his attempt to make EVs mainstream, following the model used by aircraft manufacturers.

NiMH has a lot to recommend it, but Li batteries have a greater energy density. If you packed the same weight of Li batteries into a Rav4EV, it would go farther than the NiMH version. The only reason NiMH cars seem to go farther is because they were *stuffed* with batteries.

The Volt, Prius, and their kin are generally equipped with a small Li pack, leaving plenty of room for the big gasoline engine / generator. That's why the electric range is reduced.


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## david85 (Nov 12, 2007)

Good article. Heart breaking, but good.

I remember reading about the solectria sunrise and the ground breaking trip it made. I also remember reading about how he media didn't give a rats ass and completely ignored it. The sunrise was almost completely made of composite and had some of the best aerodynamics of any car ever made. I LOVE the EV1 but the sunrise was the better design overall. 

I hope Lee Hard pays us a visit some time, because I would like to thank him for what he is trying to do. In fact it was his story of trying to rebuild the sunrise that was the reason for me signing up in the first place.

Slight correction, the battery was at 15% SOC or 85% depleted at the end of the trip.

The car drove further in an EV competition but that was at lower speeds. 375 miles. Thats 375 miles with technology that is now obsolete....we need cars like the sunrise but instead we got the prius and eventually the volt. And people wonder why I don't like hybrids.......


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