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Re: battery pricing and PHEV cost-of-ownership

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  • Ron Gremban
    ... The NiMH chemistry has lower specific energy than li-ion, but auto manufacturers are already using them in mass-produced vehicles. With the Electro Energy
    Message 1 of 9 , Oct 31, 2005
      jb_hybrid_ford wrote:

      > OK, so NiMHs are not the best choice. <snip>

      The NiMH chemistry has lower specific energy than li-ion, but auto
      manufacturers are already using them in mass-produced vehicles. With
      the Electro Energy batteries, we will be showing that NiMH batteries can
      successfully power a PHEV. Some, if not all, mass-produced PHEVs may
      well use NiMH batteries for the first few years until li-ion (or yet
      another chemistry) takes over.

      >
      >
      > As I recall Lithium Polymers had some good characterics (including
      > weight) but had problems with adequate power. I haven't heard much
      > talke about them.

      I have been considering lithium polymer cells to be a type of li-ion.
      In general, they have excellent high power handling capabilities but
      equally high prices. They may or may not have safety advantages; each
      product needs to be tested and evaluated separately. For example, 18650
      cells can have built-in pressure cutout as well as temperature cutout
      switches built in to help avoid fires, but the packaging of lithium
      polymer cells may just bulge instead of activating such a built-in switch.

      >
      > Ron said: "-- and that still wouldn't affect similar peak hill-
      > climbing and descent currents, which can last for minutes."

      This remark applied to the use of supercapacitor banks to handle peak
      currents. The point was that there can be real value to be gained by
      having the battery pack able to handle full regenerative braking, if not
      acceleration, currents, rather than depending on supercaps to do so.

      >
      > I think that the most economical PHEV would simply lose some charge
      > from an extreme downhill and require some I.C. motorized assist on
      > an extreme uphill. I don't know exactly what the extremes would be,
      > but I could see that at some point, the cost for a given performance
      > would rise dramatically. Sometimes I think there is a desire to
      > have full E.V. behavior for the first 20 miles or so, but clearly
      > that's probably not the least-cost option, especially under these
      > extreme conditions. <snip>

      I have previously talked about there being a range of EV vs. ICE
      capabilities possible for PHEVs (just as for HEVs). Near one end is the
      PRIUS+, which is capable of only limited EV operation in terms of both
      speed and acceleration; and is capable of no more than doubling gasoline
      mileage until the battery is depleted. At the other end is a serial
      hybrid with a small ICE disconnected from the drivetrain and running a
      generator as necessary to maintain the battery's state of charge above a
      minimum. Lots of things between these extremes are possible AND WILL BE
      TRIED, because no one yet knows what is optimum in the real world, and,
      in fact, the optimum may vary for different costumers' driving regimes
      -- just as the mildly hybridized Insight gets better highway mileage
      than a Prius, but the Prius does its best in city driving.

      For now, CalCars is focussing on what can be done with merely electrical
      modifications to existing full hybrid vehicles, because this is where
      the short-term leverage exists for quickly getting mass-produced PHEVs
      into the marketplace. And even such vehicles, not originally optimized
      as PHEVs, can be remarkably good! Later there will be plenty of time to
      debate the fine points of PHEV optimization.

      > "We model our effort on "Open Source" software development projects:
      > We draw on the expertise and solutions of a broad group of experts
      > and no individual owns any resulting intellectual property."
      >
      > "Since we don't keep our discussions secret, our MESSAGE ARCHIVES
      > ARE OPEN to the public. We remain highly focused, relatively low-
      > traffic and spam-free. In this working group, members post messages
      > based on their specialties."
      >
      > And from the last post:
      > > CalCars is pursuing Li-ion options that we can't yet talk about
      > > publicly.

      Well, we are trying to balance on a razor edge here. To pursue specific
      batteries, Felix and I (CalCars' two full-time volunteers) have found
      that we must respect various manufacturers' needs for confidentiality.
      This means that there are certain specifics and deals that we cannot
      discuss in our public forum until they have reached a point where we are
      able to make a public announcement, as has now occurred with Electro
      Energy Inc. This is one of the limits we have found to how thoroughly a
      project can be run as a public forum.

      >
      > I apologize for posting items off-topic. Apparently, batteries for
      > others to use fall in that category as well.

      On-topic for this list are discussions of things directly related to
      CalCars' current conversion projects, the PRIUS+ and the ESCAPE+. I
      apologize that though I try to avoid it, I, too, sometimes allow myself
      to be led off into more general PHEV discussions.

      > <snip>
      >
      > -Jim

      --
      +++++++++++++++++++++++++++++++++++++++++
      Ron Gremban, rgremban@...
      California Cars Initiative, a nonprofit organization: http://www.CalCars.org
      Moderator & Technical Lead
      http://www.priusplus.org
      PRIUS+ PHEV Conversion Group: http://groups.yahoo.com/group/priusplus
      Newsletter: http://groups.yahoo.com/group/calcars-news
      +++++++++++++++++++++++++++++++++++++++++
    • murdoch
      ... Ron: Thanks for trying to answer and further clarify and explore these battery pricing questions. ... In my Battery evaluation and production cost
      Message 2 of 9 , Nov 1, 2005
        On Thu, 27 Oct 2005 15:26:38 -0700, you wrote:

        >Though I won't answer all questions raised recently, I do think battery
        >costs and their effect on PHEV cost-of-ownership are relevant.
        >
        >However, as technical lead for a small nonprofit organization (us) I
        >have had very limited and unreliable access to volume pricing
        >information. Also, what I do have is not for public disclosure.
        >Therefore, I have had to get as much mileage as possible from the
        >snippets of information I have acquired, as well as refrain from giving
        >many specifics.
        >
        >As clearly stated in my "Battery evaluation and production cost summary"
        >of July 21, the $600/kWh NiMH price is a projection based on 150% of the
        >wholesale price I was quoted for Chinese NiMH "D" cells. I just now
        >remembered and looked up an approximate volume quote of $735/kWh for a
        >more appropriate NiMH module from a major manufacturer. It's a little
        >higher than my guess, but not out of the ballpark. Electro Energy has
        >not quoted any specific prices, but they have assured us that their
        >pricing will be "competitive". They are also working on a future Li-ion
        >product using their unique packaging.
        >
        >For Li-ion, I projected $400/kWh from an approximate real wholesale
        >price of $3 each for 18650 cells. Again, it was a tenuous strategy, but
        >appears to have made sense, as a manufacturer of large-scale Li-ion
        >batteries has recently estimated a high volume price of . . . $400/kWh!

        Ron:

        Thanks for trying to answer and further clarify and explore
        these battery pricing questions.

        In a post a couple of weeks ago you said:

        ---------------------
        "In my "Battery evaluation and production cost summary"
        message of July 21, I stated that I believe an auto
        manufacturer would currently pay $600/kWh or less for a NiMH
        battery pack capable of 150,000 miles, or $400/kWh for a
        Li-ion pack."
        ---------------------

        This confused me a bit as I mentioned, and I went back to
        read your post from then. I think the confusion was that
        you were stating things in terms of what an auto
        manufacturer 'might be willing to pay', and not in terms of
        what pricing manufacturers might be reasonably able to
        offer, going forward. This latter seems to be more of what
        you are clarifying here... what sort of pricing we can
        guestimate might be available going forward, basing this on
        a few manufacturer-side pieces of data.

        In any event, I think for now you have done some good
        research on battery cost and availability questions, so
        thanks for going over these matters. As mentioned in
        private email, it is just not possible for me and others to
        avoid wondering as to how Electro Energy intends to provide
        BEV/PHEV-suitable NiMH batteries when everyone else seems to
        be unwilling or legally precluded (or some combination) from
        doing so, but I'm not sure it's necessary to clarify that
        publicly, if it is sensitive information.

        You have also made some mention, if memory serves, of the
        comparatively unproven nature of Lithium, and to me this
        provided some explanation as to why an auto manufacturer
        might want to pay a more "skeptical" price for Lithium...
        taking into account that there are some unproven
        life-of-battery issues there, whereas with NiMH, we (both
        consumers and others) are further along in understanding the
        lifetime expectations we have for NiMH in some of our
        hybrids.

        I believe you have emphasized that there is a looming
        unanswered question out there as to
        battery-lifetime-issues-in-PHEVs, and that these questions
        are hard to answer without some years of on-road testing
        (sorry for any mis-stating of the exact issue here).
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