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  • Originally posted by SunEagle View Post
    And yet how many auto companies are jumping back into the EV field?

    Maybe GM had a solution (although expensive) but to throw it away and start from scratch seems dumb. While the Volt is better than most hybrid models it still doesn't have the (electric only) range of something like the Tesla. GM could have been leading the charge instead of catching up.
    In 1990's only CA had such emission free requirements, there was no real market for EV's then as it was mandated by the CA goberment. GM made the EV-1 for one reason and one reason only to enable themselves to sell cars in the worlds largest automotive market CA. Now it is mandated by EPA for all 50 states, and a false market exist like solar. GM did not throw away the technology. They reused it for the Volt with one change. This time they used Lithium instead of Lead Acid in the early production models before buying the patent rights for NiMh batteries in the last production run of 2002. GM prohibits anyone from ever using NiMh batteries again in automobiles. They won't even use them. But the Chevy volt today uses the same VFD Inverter and 3 phase induction AC motor. GM just got trid of the Crappy Lead acid and NiMh battery. The lithium at the time did not exist like it does today 13 years later.
    MSEE, PE

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    • Originally posted by Sunking View Post
      In 1990's only CA had such emission free requirements, there was no real market for EV's then as it was mandated by the CA goberment. GM made the EV-1 for one reason and one reason only to enable themselves to sell cars in the worlds largest automotive market CA. Now it is mandated by EPA for all 50 states, and a false market exist like solar. GM did not throw away the technology. They reused it for the Volt with one change. This time they used Lithium instead of Lead Acid in the early production models before buying the patent rights for NiMh batteries in the last production run of 2002. GM prohibits anyone from ever using NiMh batteries again in automobiles. They won't even use them. But the Chevy volt today uses the same VFD Inverter and 3 phase induction AC motor. GM just got trid of the Crappy Lead acid and NiMh battery. The lithium at the time did not exist like it does today 13 years later.
      Some of that I did not know especially about the NiMh batteries. Battery technology still improves but boy does it seem in slow motion.

      Of course I remember those NiCd batteries that developed memories. Boy they were crap.

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      • Originally posted by Sunking View Post
        Who fed you that garbage and why did you eat it? All batteries have shelf and cycle life, whichever comes first. a really good quality Lithium battery has around 2000 cycles if cycled between 20 and 80% DOD or up to 8 to 10 years sitting on a shelf.
        Well, I wouldn't call it garbage; only incomplete information. 2000 cycles would mean replacing batteries every 5 years or so. Pretty expensive. Would the idea be feasible if the storage system was capable of 20000 cycles?

        You would think that Tesla Motors would have this same issue too and, in fact, after doing a bit of research, one finds that they do. Tesla's solution is to recycle the car battery at no charge to achieve their warranty. So you are paying once but can receive multiple batteries over the life of the car. Since the upcoming battery factory will also be a re-cycling facility, we may have this same model to look forward to when/if they decide to go into the renewable energy storage market.
        4KW system featuring Suniva OPT265/Enphase M215

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        • Originally posted by Sunking View Post
          GM prohibits anyone from ever using NiMh batteries again in automobiles.
          GM has no say in the NiMH technology: they sold the patents - which they had acquired from Ovonics - to Texaco(Chevron) in 2000. It's the latter that has restricted their use by not selling in small quantities. Makes some sense for an oil company to hinder battery development for EV's, I suppose. Furthermore, patents don't last for ever and indeed, the patents used to limit NiMH application to EVs apparently run out in 2014-15 timeframe. Actually, I'm surprised they last that long as GM bought the technology from Ovonics in 1994 and at that time, patents had a term of 17 years from issuance date. Maybe they had some additional patents that issued later. In any event, it appears that NiMH technology for large battery systems will soon be freed from Chevron's restrictions.

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          • Originally posted by Ian S View Post
            GM has no say in the NiMH technology: they sold the patents - which they had acquired from Ovonics - to Texaco(Chevron) in 2000. It's the latter that has restricted their use by not selling in small quantities. Makes some sense for an oil company to hinder battery development for EV's, I suppose. Furthermore, patents don't last for ever and indeed, the patents used to limit NiMH application to EVs apparently run out in 2014-15 timeframe. Actually, I'm surprised they last that long as GM bought the technology from Ovonics in 1994 and at that time, patents had a term of 17 years from issuance date. Maybe they had some additional patents that issued later. In any event, it appears that NiMH technology for large battery systems will soon be freed from Chevron's restrictions.
            Yes I know but NiMh will never be used again for an EV, energy density is to low and $/wh cost is more than lithium. So you have a moot point that makes no difference.
            MSEE, PE

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            • Originally posted by Sunking View Post
              Yes I know but NiMh will never be used again for an EV, energy density is to low and $/wh cost is more than lithium. So you have a moot point that makes no difference.
              Just setting the record straight on who was responsible for restricting the NiMH technology.

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              • NiMH sucks anyway. It's only marginally better than NiCad.

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                • Originally posted by JCP View Post
                  NiMH sucks anyway. It's only marginally better than NiCad.
                  That was my point. Neither Nickel technology worked then or now. GM bought the rights during EV-1 program under the assumption they would continue to make the EV-1. When CA changed CARB mandates, there was no longer a market for the EV-1 and it was cancelled. Today no one would use a Nickel anything battery in an EV. GM sold off the unused asset for cash flow. Who ever owns it will make money, just not in the EV market.
                  MSEE, PE

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                  • Originally posted by Sunking View Post
                    That was my point. Neither Nickel technology worked then or now. GM bought the rights during EV-1 program under the assumption they would continue to make the EV-1. When CA changed CARB mandates, there was no longer a market for the EV-1 and it was cancelled. Today no one would use a Nickel anything battery in an EV. GM sold off the unused asset for cash flow. Who ever owns it will make money, just not in the EV market.
                    I think that NiMH is done as a technology. There's probably a niche use somewhere, but basically Lithium has won as a battery technology.

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                    • Originally posted by JCP View Post
                      I think that NiMH is done as a technology. There's probably a niche use somewhere, but basically Lithium has won as a battery technology.
                      If nothing else, the voltage drop at End Of Charge for high rate charging makes NiMH just too unstable for most users of large capacity banks. If you do not catch the EOC for any reason, overheating and venting or worse are not far away.
                      EV use depends, among other things, on the control circuitry staying powered off the battery bank so that it knows the charging history at all times.
                      SunnyBoy 3000 US, 18 BP Solar 175B panels.

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