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Re: [solectria_ev] Thermal Management System

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  • d. Bouton Baldridge
    Hi Rex, you have done well getting 7 years and 22,000 miles. I have not been so fortunate with Pb. Ok not too sure of the miles maybe 3000. Since the main
    Message 1 of 29 , Dec 3, 2012
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      Hi Rex, you have done well getting 7 years and 22,000 miles. I have not been so fortunate with Pb.
      Ok not too sure of the miles maybe 3000. Since the main reason for a small pack was cost I also adopted a different attitude for the car. Being an early model the 30 -40 mile range on 90 ah  l/a is still pretty much possible with the 40 Ah lithium. Not needing to drive that much every a day any longer (retired) I wanted to find a solution to the problem of replacing packs every 18 months or 2 years. My goal was to get the overall cost of driving electric down, and replacing packs so frequently was the number one culprit. Since my lithium pack cost just a bit more than the Pb four years ago, I feel that my goal is proving to be successful. I have added the solar feature to not only reduce the cost more, but I wanted to prove to myself that it could be done without using supplemental power which now influences my driving as well. I will have driven 2.5 years without even plugging in. I drive only the distance that will allow me to recharge from the sun
      the next day, which is qute a challenge during the winter. So distance driving is for somebody else. Range anxiety is an issue all of us EVers  have to deal with in our public image. If you want to go long distances in an EV it can be done but at a steep price for a large pack, but how much do you really need? Those 3000 miles were hundreds of short trips like the average driver does every day; if an ICE were used they would be the least efficient and most polluting miles, not so with an EV. Hope this helps.
      Bouty



      ________________________________
      From: Rex Allison <ev64bug@...>
      To: "solectria_ev@yahoogroups.com" <solectria_ev@yahoogroups.com>
      Sent: Monday, December 3, 2012 11:33 AM
      Subject: Re: [solectria_ev] Thermal Management System

       
      I have one question for Bouty:
      How many miles do you have on your pack?

      One question for the group:
      Does anyone have the dimension for the inside of the front battery box?

      I'm really interesting in Bouty's configuration. After 7 years and 22,000 miles my poor old Pb pack is on it's last legs. I'm able to get 22 to 24Ahrs out of the pack which is enough for a round trip to work and a very short side trip. Since the pack is fairly weak it takes 1.5 to 1.6Ahr per mile.  I'm trying to hold out until summer for my switch to lithium when the weather is a little better and I have my battery monitor tested out. I'm interested in putting 49 40Ahr CALB "grey" cells (CA40BFI) for a couple of reasons:

      1.  If my measurements are correct the complete pack should fit in the front battery box in a 7x7 array. By moving the charger up front all the 156V wiring will be under the hood with a very short run between the pack and the controller.

      2. The pack cost
      is comparable to if not cheaper than the Deka equivalent. 40Ahr CALBs are around $55 each. 49 x $55 = $2,695 before tax and shipping.  13 Deka batteries would have to be $207 just to be comparable ($2,695 / 13 = $207 approx.)

      3. My car will be shedding 661lb. The CALB cells at 3.3lb each x 49 = 161 lb vs the 822lb (63.2lb x 13) of the current pack. I'm probably going to have to find the original springs for the Geo, otherwise the car will feel like it is permanently going down a hill.

      4. The "blue" CALBs (SE40AHA) already have fantastic C ratings and the "grey" cells have better cold weather performance. The max current of the force at around 240A dc should be no problem for the 40Ahr cells, they should be able to handle C6. There is some interesting test data on the cells: http://blog.evtv.me/2012/06/battery-jump-shift/

      I know the general consensus is that 60 Ahr or 100 Ahr is preferable, but I've been logging all my driving for the past 7 years, most days I use between 16Ahrs and 20Ahrs and only a few times did I even come close to 35Ahrs.

      ________________________________
      From: d. Bouton Baldridge <mailto:cfrkeepr%40yahoo.com>
      To: "mailto:solectria_ev%40yahoogroups.com" <mailto:solectria_ev%40yahoogroups.com>
      Sent: Sunday, December 2, 2012 7:26 AM
      Subject: Re: [solectria_ev] Thermal Management System


       
      Hi Wade,
       In my opinion, the balance thing has been greatly over blown and your readings are perefectly acceptable especially after using so much capacity having only +/-.1 v or so from the mean is fantastic. The big thing is avoiding going beyond the knees and your system seems to be working just fine doing that. As for the Ahmeter issue, It has been my experience that voltage is not a reliable means for determining capacity. In my case I have found the reaching the limiting voltage was caused by the pack warming up; for me it was the sun. Now that the ambient temperature is lower in the winter season my charge resets closer to zero, but in summer it stops on the plus side by .1 ah each cycle when the outside temp is above 80 degrees. My guess for you is that when you charge for a few hours, the pack temp increases higher than when you were driving and the voltage is slightly higher as a result this stops the charger earlier than
      the previous Ahour
      reading. I am not sure if this is happening as a function of breaking in or aging. But it was not an issue with lead since it woul be overcharged routinely and had the automatic reset.  I am a few months shy of 4 years and this slight precession is only an annoyance it has not seemed to impact the utility of my pack. Since I have a pretty long warm season I would just occasionaly reset the Ah meter to zero just so I wouldn't have to remember every time. Now that my cells are getting twice as old as any Pb pack would last, I am getting into new territory for longevity and at some point I might find some of these answers, but for now I am saying congratulation on your project FWIW,
      Bouty

      ________________________________
      From: Wade Perry <mailto:perrypeas%40gmail.com>
      To: mailto:solectria_ev%40yahoogroups.com
      Sent: Sunday, December 2, 2012 1:47 AM
      Subject: [solectria_ev] Thermal Management System

       
      Greetings all- I've driven over 1,000 miles on lithium now.

      I drove a fair bit today, it was mostly empty when I was coming back home
      from the last errand so I thought I'd take the long way home and discharge
      a bit more than I usually do. Until today the maximum I'd taken out is
      probably around 45 Ahr. I had set my limit around 50 to be safe.
      So after I got home I drove the block a few times with the heater on. Went
      well past 50. I measured pack voltage and some individual cells while I
      did this and felt fairly safe as I was getting down towards the bottom.
      Finally drove it around one last time in econ with no heater and it was
      around 57.5 when I was done. Then I ran the heater by itself to get it to
      59. Took the voltage on each cell.
      Made a new column to my battery balancing spreadsheet, it's here-
      https://docs.google.com/spreadsheet/pub?key=0An5nm8itUMMcdHhQV3RsSUdfbzRTQkFlNmtaSy05MHc&output=html

      The cells were springing back as I was measuring them. When I was done I
      went back and measured CK, where I'd started measuring the pack. it was
      .04 volts higher than I'd written down the first time. By the time I was
      finishing measuring, all the cells were coming in around 3.04 or 3.05. So
      they're reasonably well balanced.

      One cell stands out. JA. It measured 2.93 when its adjacent cells were
      measuring an entire ~0.10 volt higher. I haven't figured it out yet.
      Other than it happens to be the one that I noticed arrived from the
      factory at 4.23% below 50% SOC. You can see that on the sheet. It stood
      out at the time because all the other cells came in at 1 or 2% over 50.
      This was the only one that was below, and by a fair amount.

      Anyway then I ran the heater some more, watching JA in particular. It
      would have been cool to have a graph of all the cells at once. But they
      were falling off quite quickly. Some dipped down to 2.75 or so. JA dipped
      all the way down to 2.50. But I discharged down to a full 60.00 Ahr on my
      counter! Finished with a pack voltage of around 160. (which was
      undoubtedly springing up also. I didn't wait around to check but plugged
      in the charger so I can drive again tomorrow)

      This is great, because I had feared I was losing capacity permanently by
      charging below freezing. I'd hoped this wasn't the case, but was concerned
      because on especially cold days there'd be +1.00 or +2.00 Ahr still left on
      the counter when the charger shut off. Warmer days I'd be back to -0.14 or
      something like that. I'd been worried that I was gradually damaging the
      cells.

      Apparently I'm not. Or at least not to the extent I'd feared. This is
      with a battery box that's not even put together yet- the 60 Ahr cells are
      taller than the gels I took out, so when I finally do get things put
      together properly, I'll need to shim the cover over the battery box. Right
      now it rests on top of the cells, so there's probably a 1" space all
      around, letting cold air in. I did put in a 60watt incandescent light bulb
      back there to keep things warmer (and bright and cheery) in the battery
      box, whenever the car's plugged in.

      So. What I'd really like to do is hook up the Solectria heating mats to AC
      power, so I can be more setup for winter. I myself took it apart back in
      August, but obviously didn't pay much attention to what I was doing. I've
      searched this list repeatedly but can't find anything that talks about
      where the AC power hooks up to the heaters / sensors... Can anyone point
      me to a resource about this?

      Thanks for the help!

      Wade Perry
      1998 Force
      56 CALB CA 60 Ahr

      [Non-text portions of this message have been removed]

      [Non-text portions of this message have been removed]

      [Non-text portions of this message have been removed]




      [Non-text portions of this message have been removed]
    • d. Bouton Baldridge
      Hi Wade,  It is only a theory but I think that while you are charging at the higher rate steady state it tends to heat the cell electrolite higher than when
      Message 2 of 29 , Dec 3, 2012
      • 0 Attachment
        Hi Wade,
         It is only a theory but I think that while you are charging at the higher rate steady state it tends to heat the cell electrolite higher than when you were driving; in my case the cells are heated by the high outside temps and cabin. A warmer cell increases the voltage and thus the charger reaches voltage limit before the entire Ah capacity is reached just slightly less. I have withnesses my cell arround 90 degrees F and the car acts like it is in power mode good acceleration and the converse is true when they are below 50 F, so I know that these cells behave this way. So your cells are colder before charging, I think.
        Bouty 


        ________________________________
        From: Wade Perry <perrypeas@...>
        To: solectria_ev@yahoogroups.com
        Sent: Monday, December 3, 2012 4:30 PM
        Subject: Re: [solectria_ev] Thermal Management System

         
        Hi Wolf.
        Yes that was my understanding.
        It's been below freezing recently, sometimes a fair bit below freezing,
        like -15C. My kids are enjoying our backyard skating rink.
        But I knew the cells wouldn't be as cold as the outside air because I've
        been driving them, and recharging, both of which should generate some heat
        within the cell itself. However they don't generate all that much heat
        really even when you're pushing them, which a Force isn't really capable of
        doing anyway, so I was nervous. The phenomenon that Bouty and Tom are
        calling "precession" was getting me concerned. Especially because it
        happened when it was COLDER. That's why I was so happy to get the full
        60Ahr out... But the full capacity might be partly because I'm breaking
        the cells in too.

        Wolf a question for you- What do you think is the maximum voltage the
        AC325 controller can handle? I have 56 cells in the car now, could I add
        any more??? :)

        Bouty- I don't understand why you should see a higher incidence of
        precession when it's warmer, while I see a higher incidence when it's
        colder.

        Wade

        On Sun, Dec 2, 2012 at 10:23 AM, Wolf <mailto:wolf%40wolftronix.com> wrote:

        > I would not charge lithium ion batteries that are below freezing, you will
        > electroplate metallic lithium and ruin the battery.
        >
        > Do a quick Google search on electroplating lithium when charging below
        > freezing.
        > On Dec 2, 2012 12:47 AM, "Wade Perry" <mailto:perrypeas%40gmail.com> wrote:
        >
        > > **
        > >
        > >
        > > Greetings all- I've driven over 1,000 miles on lithium now.
        > >
        > > I drove a fair bit today, it was mostly empty when I was coming back home
        > > from the last errand so I thought I'd take the long way home and
        > discharge
        > > a bit more than I usually do. Until today the maximum I'd taken out is
        > > probably around 45 Ahr. I had set my limit around 50 to be safe.
        > > So after I got home I drove the block a few times with the heater on.
        > Went
        > > well past 50. I measured pack voltage and some individual cells while I
        > > did this and felt fairly safe as I was getting down towards the bottom.
        > > Finally drove it around one last time in econ with no heater and it was
        > > around 57.5 when I was done. Then I ran the heater by itself to get it to
        > > 59. Took the voltage on each cell.
        > > Made a new column to my battery balancing spreadsheet, it's here-
        > >
        > >
        > https://docs.google.com/spreadsheet/pub?key=0An5nm8itUMMcdHhQV3RsSUdfbzRTQkFlNmtaSy05MHc&output=html
        > >
        > > The cells were springing back as I was measuring them. When I was done I
        > > went back and measured CK, where I'd started measuring the pack. it was
        > > .04 volts higher than I'd written down the first time. By the time I was
        > > finishing measuring, all the cells were coming in around 3.04 or 3.05. So
        > > they're reasonably well balanced.
        > >
        > > One cell stands out. JA. It measured 2.93 when its adjacent cells were
        > > measuring an entire ~0.10 volt higher. I haven't figured it out yet.
        > > Other than it happens to be the one that I noticed arrived from the
        > > factory at 4.23% below 50% SOC. You can see that on the sheet. It stood
        > > out at the time because all the other cells came in at 1 or 2% over 50.
        > > This was the only one that was below, and by a fair amount.
        > >
        > > Anyway then I ran the heater some more, watching JA in particular. It
        > > would have been cool to have a graph of all the cells at once. But they
        > > were falling off quite quickly. Some dipped down to 2.75 or so. JA dipped
        > > all the way down to 2.50. But I discharged down to a full 60.00 Ahr on my
        > > counter! Finished with a pack voltage of around 160. (which was
        > > undoubtedly springing up also. I didn't wait around to check but plugged
        > > in the charger so I can drive again tomorrow)
        > >
        > > This is great, because I had feared I was losing capacity permanently by
        > > charging below freezing. I'd hoped this wasn't the case, but was
        > concerned
        > > because on especially cold days there'd be +1.00 or +2.00 Ahr still left
        > on
        > > the counter when the charger shut off. Warmer days I'd be back to -0.14
        > or
        > > something like that. I'd been worried that I was gradually damaging the
        > > cells.
        > >
        > > Apparently I'm not. Or at least not to the extent I'd feared. This is
        > > with a battery box that's not even put together yet- the 60 Ahr cells are
        > > taller than the gels I took out, so when I finally do get things put
        > > together properly, I'll need to shim the cover over the battery box.
        > Right
        > > now it rests on top of the cells, so there's probably a 1" space all
        > > around, letting cold air in. I did put in a 60watt incandescent light
        > bulb
        > > back there to keep things warmer (and bright and cheery) in the battery
        > > box, whenever the car's plugged in.
        > >
        > > So. What I'd really like to do is hook up the Solectria heating mats to
        > AC
        > > power, so I can be more setup for winter. I myself took it apart back in
        > > August, but obviously didn't pay much attention to what I was doing. I've
        > > searched this list repeatedly but can't find anything that talks about
        > > where the AC power hooks up to the heaters / sensors... Can anyone point
        > > me to a resource about this?
        > >
        > > Thanks for the help!
        > >
        > > Wade Perry
        > > 1998 Force
        > > 56 CALB CA 60 Ahr
        > >
        > > [Non-text portions of this message have been removed]
        > >
        > >
        > >
        >
        >
        > [Non-text portions of this message have been removed]
        >
        >
        >
        > ------------------------------------
        >
        > Yahoo! Groups Links
        >
        >
        >
        >

        [Non-text portions of this message have been removed]




        [Non-text portions of this message have been removed]
      • theoldcars@aol.com
        Just a word of warning The CALB cells are not rated as many sellers on the Internet are showing 3C and 4C on their web sites. The SE series was rated by CALB
        Message 3 of 29 , Dec 3, 2012
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          Just a word of warning

          The CALB cells are not rated as many sellers on the Internet are showing 3C
          and 4C on their web sites. The SE series was rated by CALB at 1C and many
          have put them under loads of 3C or 4C. There is no data that I am aware of
          that shows cycle life under these higher C rates but it will be less.

          The new CA series which are also called the gray cells are rated at 2C by
          CALB.

          If your going to put a higher C rate on a CALB cell I would recommend it be
          the CA series.

          CALB for the most part has stopped selling the SE series except for a few
          sizes. The demand for the SE series has almost totally gone away with the
          release of the CA series.

          Jack from EVTV gives out some off some really off the wall advise and
          information. While some of what he does is good he also chimes in with baseless
          comments or beliefs that have no merit.

          On the 40Ah cells your going to see far more voltage sag under load. Cycle
          life would be less but as you point out its going to be a savings
          regardless over lead. I would highly recommend the CA 60Ah cells. The 60Ah cells
          hold their voltage very well. I know of one person who parallel two 40Ah of
          SE40 and their voltage sags more then a pack of 60Ah CA cells in series.

          Don Blazer


          In a message dated 12/3/2012 8:34:09 A.M. Pacific Standard Time,
          ev64bug@... writes:




          I have one question for Bouty:
          How many miles do you have on your pack?

          One question for the group:
          Does anyone have the dimension for the inside of the front battery box?

          I'm really interesting in Bouty's configuration. After 7 years and 22,000
          miles my poor old Pb pack is on it's last legs. I'm able to get 22 to
          24Ahrs out of the pack which is enough for a round trip to work and a very short
          side trip. Since the pack is fairly weak it takes 1.5 to 1.6Ahr per mile.
          I'm trying to hold out until summer for my switch to lithium when the
          weather is a little better and I have my battery monitor tested out. I'm
          interested in putting 49 40Ahr CALB "grey" cells (CA40BFI) for a couple of
          reasons:

          1. If my measurements are correct the complete pack should fit in the
          front battery box in a 7x7 array. By moving the charger up front all the 156V
          wiring will be under the hood with a very short run between the pack and
          the controller.

          2. The pack cost
          is comparable to if not cheaper than the Deka equivalent. 40Ahr CALBs are
          around $55 each. 49 x $55 = $2,695 before tax and shipping. 13 Deka
          batteries would have to be $207 just to be comparable ($2,695 / 13 = $207 approx.)

          3. My car will be shedding 661lb. The CALB cells at 3.3lb each x 49 = 161
          lb vs the 822lb (63.2lb x 13) of the current pack. I'm probably going to
          have to find the original springs for the Geo, otherwise the car will feel
          like it is permanently going down a hill.

          4. The "blue" CALBs (SE40AHA) already have fantastic C ratings and the
          "grey" cells have better cold weather performance. The max current of the
          force at around 240A dc should be no problem for the 40Ahr cells, they should
          be able to handle C6. There is some interesting test data on the cells:
          _http://blog.evtv.me/2012/06/battery-jump-shift/_
          (http://blog.evtv.me/2012/06/battery-jump-shift/)

          I know the general consensus is that 60 Ahr or 100 Ahr is preferable, but
          I've been logging all my driving for the past 7 years, most days I use
          between 16Ahrs and 20Ahrs and only a few times did I even come close to 35Ahrs.

          ________________________________
          From: d. Bouton Baldridge <_cfrkeepr@..._
          (mailto:cfrkeepr@...) >
          To: "_solectria_ev@yahoogroups.com_ (mailto:solectria_ev@yahoogroups.com) "
          <_solectria_ev@yahoogroups.com_ (mailto:solectria_ev@yahoogroups.com) >
          Sent: Sunday, December 2, 2012 7:26 AM
          Subject: Re: [solectria_ev] Thermal Management System



          Hi Wade,
          In my opinion, the balance thing has been greatly over blown and your re
          adings are perefectly acceptable especially after using so much capacity
          having only +/-.1 v or so from the mean is fantastic. The big thing is avoiding
          going beyond the knees and your system seems to be working just fine doing
          that. As for the Ahmeter issue, It has been my experience that voltage is
          not a reliable means for determining capacity. In my case I have found the
          reaching the limiting voltage was caused by the pack warming up; for me it
          was the sun. Now that the ambient temperature is lower in the winter season
          my charge resets closer to zero, but in summer it stops on the plus side
          by .1 ah each cycle when the outside temp is above 80 degrees. My guess for
          you is that when you charge for a few hours, the pack temp increases higher
          than when you were driving and the voltage is slightly higher as a result
          this stops the charger earlier than
          the previous Ahour
          reading. I am not sure if this is happening as a function of breaking in
          or aging. But it was not an issue with lead since it woul be overcharged
          routinely and had the automatic reset. I am a few months shy of 4 years and
          this slight precession is only an annoyance it has not seemed to impact the
          utility of my pack. Since I have a pretty long warm season I would just
          occasionaly reset the Ah meter to zero just so I wouldn't have to remember
          every time. Now that my cells are getting twice as old as any Pb pack would
          last, I am getting into new territory for longevity and at some point I might
          find some of these answers, but for now I am saying congratulation on your
          project FWIW,
          Bouty

          ________________________________
          From: Wade Perry <_perrypeas@..._ (mailto:perrypeas@...) >
          To: _solectria_ev@yahoogroups.com_ (mailto:solectria_ev@yahoogroups.com)
          Sent: Sunday, December 2, 2012 1:47 AM
          Subject: [solectria_ev] Thermal Management System


          Greetings all- I've driven over 1,000 miles on lithium now.

          I drove a fair bit today, it was mostly empty when I was coming back home
          from the last errand so I thought I'd take the long way home and discharge
          a bit more than I usually do. Until today the maximum I'd taken out is
          probably around 45 Ahr. I had set my limit around 50 to be safe.
          So after I got home I drove the block a few times with the heater on. Went
          well past 50. I measured pack voltage and some individual cells while I
          did this and felt fairly safe as I was getting down towards the bottom.
          Finally drove it around one last time in econ with no heater and it was
          around 57.5 when I was done. Then I ran the heater by itself to get it to
          59. Took the voltage on each cell.
          Made a new column to my battery balancing spreadsheet, it's here-
          _https://docs.google.com/spreadsheet/pub?key=0An5nm8itUMMcdHhQV3RsSUdfbzRTQk
          FlNmtaSy05MHc&output=html_
          (https://docs.google.com/spreadsheet/pub?key=0An5nm8itUMMcdHhQV3RsSUdfbzRTQkFlNmtaSy05MHc&output=html)

          The cells were springing back as I was measuring them. When I was done I
          went back and measured CK, where I'd started measuring the pack. it was
          .04 volts higher than I'd written down the first time. By the time I was
          finishing measuring, all the cells were coming in around 3.04 or 3.05. So
          they're reasonably well balanced.

          One cell stands out. JA. It measured 2.93 when its adjacent cells were
          measuring an entire ~0.10 volt higher. I haven't figured it out yet.
          Other than it happens to be the one that I noticed arrived from the
          factory at 4.23% below 50% SOC. You can see that on the sheet. It stood
          out at the time because all the other cells came in at 1 or 2% over 50.
          This was the only one that was below, and by a fair amount.

          Anyway then I ran the heater some more, watching JA in particular. It
          would have been cool to have a graph of all the cells at once. But they
          were falling off quite quickly. Some dipped down to 2.75 or so. JA dipped
          all the way down to 2.50. But I discharged down to a full 60.00 Ahr on my
          counter! Finished with a pack voltage of around 160. (which was
          undoubtedly springing up also. I didn't wait around to check but plugged
          in the charger so I can drive again tomorrow)

          This is great, because I had feared I was losing capacity permanently by
          charging below freezing. I'd hoped this wasn't the case, but was concerned
          because on especially cold days there'd be +1.00 or +2.00 Ahr still left on
          the counter when the charger shut off. Warmer days I'd be back to -0.14 or
          something like that. I'd been worried that I was gradually damaging the
          cells.

          Apparently I'm not. Or at least not to the extent I'd feared. This is
          with a battery box that's not even put together yet- the 60 Ahr cells are
          taller than the gels I took out, so when I finally do get things put
          together properly, I'll need to shim the cover over the battery box. Right
          now it rests on top of the cells, so there's probably a 1" space all
          around, letting cold air in. I did put in a 60watt incandescent light bulb
          back there to keep things warmer (and bright and cheery) in the battery
          box, whenever the car's plugged in.

          So. What I'd really like to do is hook up the Solectria heating mats to AC
          power, so I can be more setup for winter. I myself took it apart back in
          August, but obviously didn't pay much attention to what I was doing. I've
          searched this list repeatedly but can't find anything that talks about
          where the AC power hooks up to the heaters / sensors... Can anyone point
          me to a resource about this?

          Thanks for the help!

          Wade Perry
          1998 Force
          56 CALB CA 60 Ahr

          [Non-text portions of this message have been removed]

          [Non-text portions of this message have been removed]

          [Non-text portions of this message have been removed]






          [Non-text portions of this message have been removed]
        • Chandler Chip
          Geo: Ooops! My brain cramp. Thanks for the correction. Chip Chandler cchandler66@roadrunner.com ... [Non-text portions of this message have been removed]
          Message 4 of 29 , Dec 4, 2012
          • 0 Attachment
            Geo: Ooops! My brain cramp. Thanks for the correction.

            Chip Chandler
            cchandler66@...

            On Dec 3, 2012, at 7:25 PM, geo_homsy2 <geo.homsy@...> wrote:

            > Chip-
            >
            > are you confusing the charger's thermal monitoring system with the thermal management system?
            >
            > In my 1999 force, the factory stock condition was:
            >
            > * two NTC thermistors mounted inside ring lugs, one screwed onto a battery post in each box, plugged into the charger interface box you describe.
            >
            > * two thermal management boxes, small black plastic, 1x2x4", velcro'd to the top of the batteries, again one in front, one in the rear. These boxes each have a bi-metallic type thermal snap-switch, to turn on the heating pads. They are powered from the AC junction box on the rear-left fender well.
            >
            > It is the latter system I believe Wade is referring to. It is completely independent of the charger.
            >
            > //Geo
            >
            > --- In solectria_ev@yahoogroups.com, Chandler Chip <cchandler66@...> wrote:
            > >
            > > Wade:
            > > The junction box on my 1997 Force leads out of the BC3300 charger and I'll assume it was originally similar for your 1998. Inside this box is a complex circuit board with some of the leads going out to the thermal management system. Matching that circuitry with your Zivan charger might be difficult, but you might go a simpler route as Solectria did in the 1996 Force, just fused leads off the power input before the power leads go to the charger. My 1996 has dual BC1000 chargers, taking only 110 volts, and in the junction box two 12amp 250 volt fuses on the two leads to the temp sensor boxes. Your Zivan and heater pads probably take 240 volts.
            > >
            > > My temp readings are showing quite a difference, as it gets colder here, between the center of the pack and outside edge, both after running and charging. I don't know what long term effects this might have on cell conditions and longevity, that is, having the center cells working at a higher temperature than the cells at the edges (also this would make a complex scenario for precession). I have no insulation (and no room for it), but would recommend as much insulation as you can install, under and around. I found when I tried originally heating lead acid, the electric bill was significant even with insulation. I believe the temp sensors are set for 70F degrees, and it would be wonderful if they could be adjusted to say 40F or replaced for 40F. I am still getting reasonable performance with the center pack starting temp at 25F with 1.5Ah/mile (TS 160Ah cells).
            > >
            > > Chip Chandler
            > > cchandler66@...
            > >
            > > On Dec 3, 2012, at 3:34 PM, Wade Perry <perrypeas@...> wrote:
            > >
            > > > Thanks for the help Chip.
            > > > I see those two pages, that's helpful.
            > > > I kept the heating pads (with the hard plastic over top).
            > > > I still have the temp sensor boxes, I haven't changed any of that (I did
            > > > unplug and remove the ones in the front box).
            > > > The temp sensor box in the rear battery box was indeed on top of the gel
            > > > cels when I started. It's still plugged in, I just left it off to the side
            > > > when I took the gels out.
            > > > However I don't think I have the actual AC junction box anymore. Someone
            > > > had changed the charger to a Zivan NG5 before I bought the car, maybe the
            > > > junction box was lost then. I do know the AC power came straight into the
            > > > NG5.
            > > > Insulation I hadn't thought about too much- the gels came with a bunch of
            > > > pink- type insulation material which I used around the lithiums too. I was
            > > > just going to close up the box and see how well it did.
            > > > Wade Perry
            > > >
            > > > On Sun, Dec 2, 2012 at 6:59 AM, Chandler Chip <cchandler66@...>wrote:
            > > >
            > > > > On the file listing for this website, check out the 1998 Force Service
            > > > > manual (Silverman), pages 49 and 53 in the appendix. They show the wiring
            > > > > for the Thermal Management System starting from the AC junction box near
            > > > > the charger and leading to the temp sensor boxes, one in each battery box,
            > > > > if you still have the components for them. Those sensor boxes should be
            > > > > installed on top of the batteries. Are your heating mats still in the
            > > > > battery boxes under your new batteries? What insulation do you plan on
            > > > > installing under and around your cells?
            > > > >
            > > > >
            > > > > Chip Chandler
            > > > > cchandler66@...
            > > > >
            > > > > On Dec 2, 2012, at 1:47 AM, Wade Perry <perrypeas@...> wrote:
            > > > >
            > > > > > Greetings all- I've driven over 1,000 miles on lithium now.
            > > > > >
            > > > > > I drove a fair bit today, it was mostly empty when I was coming back home
            > > > > > from the last errand so I thought I'd take the long way home and
            > > > > discharge
            > > > > > a bit more than I usually do. Until today the maximum I'd taken out is
            > > > > > probably around 45 Ahr. I had set my limit around 50 to be safe.
            > > > > > So after I got home I drove the block a few times with the heater on.
            > > > > Went
            > > > > > well past 50. I measured pack voltage and some individual cells while I
            > > > > > did this and felt fairly safe as I was getting down towards the bottom.
            > > > > > Finally drove it around one last time in econ with no heater and it was
            > > > > > around 57.5 when I was done. Then I ran the heater by itself to get it to
            > > > > > 59. Took the voltage on each cell.
            > > > > > Made a new column to my battery balancing spreadsheet, it's here-
            > > > > >
            > > > > https://docs.google.com/spreadsheet/pub?key=0An5nm8itUMMcdHhQV3RsSUdfbzRTQkFlNmtaSy05MHc&output=html
            > > > > >
            > > > > > The cells were springing back as I was measuring them. When I was done I
            > > > > > went back and measured CK, where I'd started measuring the pack. it was
            > > > > > .04 volts higher than I'd written down the first time. By the time I was
            > > > > > finishing measuring, all the cells were coming in around 3.04 or 3.05. So
            > > > > > they're reasonably well balanced.
            > > > > >
            > > > > > One cell stands out. JA. It measured 2.93 when its adjacent cells were
            > > > > > measuring an entire ~0.10 volt higher. I haven't figured it out yet.
            > > > > > Other than it happens to be the one that I noticed arrived from the
            > > > > > factory at 4.23% below 50% SOC. You can see that on the sheet. It stood
            > > > > > out at the time because all the other cells came in at 1 or 2% over 50.
            > > > > > This was the only one that was below, and by a fair amount.
            > > > > >
            > > > > > Anyway then I ran the heater some more, watching JA in particular. It
            > > > > > would have been cool to have a graph of all the cells at once. But they
            > > > > > were falling off quite quickly. Some dipped down to 2.75 or so. JA dipped
            > > > > > all the way down to 2.50. But I discharged down to a full 60.00 Ahr on my
            > > > > > counter! Finished with a pack voltage of around 160. (which was
            > > > > > undoubtedly springing up also. I didn't wait around to check but plugged
            > > > > > in the charger so I can drive again tomorrow)
            > > > > >
            > > > > > This is great, because I had feared I was losing capacity permanently by
            > > > > > charging below freezing. I'd hoped this wasn't the case, but was
            > > > > concerned
            > > > > > because on especially cold days there'd be +1.00 or +2.00 Ahr still left
            > > > > on
            > > > > > the counter when the charger shut off. Warmer days I'd be back to -0.14
            > > > > or
            > > > > > something like that. I'd been worried that I was gradually damaging the
            > > > > > cells.
            > > > > >
            > > > > > Apparently I'm not. Or at least not to the extent I'd feared. This is
            > > > > > with a battery box that's not even put together yet- the 60 Ahr cells are
            > > > > > taller than the gels I took out, so when I finally do get things put
            > > > > > together properly, I'll need to shim the cover over the battery box.
            > > > > Right
            > > > > > now it rests on top of the cells, so there's probably a 1" space all
            > > > > > around, letting cold air in. I did put in a 60watt incandescent light
            > > > > bulb
            > > > > > back there to keep things warmer (and bright and cheery) in the battery
            > > > > > box, whenever the car's plugged in.
            > > > > >
            > > > > > So. What I'd really like to do is hook up the Solectria heating mats to
            > > > > AC
            > > > > > power, so I can be more setup for winter. I myself took it apart back in
            > > > > > August, but obviously didn't pay much attention to what I was doing. I've
            > > > > > searched this list repeatedly but can't find anything that talks about
            > > > > > where the AC power hooks up to the heaters / sensors... Can anyone point
            > > > > > me to a resource about this?
            > > > > >
            > > > > > Thanks for the help!
            > > > > >
            > > > > > Wade Perry
            > > > > > 1998 Force
            > > > > > 56 CALB CA 60 Ahr
            > > > > >
            > > > > > [Non-text portions of this message have been removed]
            > > > > >
            > > > > >
            > > > >
            > > > >
            > > > >
            > > > > [Non-text portions of this message have been removed]
            > > > >
            > > > >
            > > > >
            > > > > ------------------------------------
            > > > >
            > > > > Yahoo! Groups Links
            > > > >
            > > > >
            > > > >
            > > > >
            > > >
            > > > [Non-text portions of this message have been removed]
            > > >
            > > >
            > >
            > >
            > >
            > > [Non-text portions of this message have been removed]
            > >
            >
            >



            [Non-text portions of this message have been removed]
          • d. Bouton Baldridge
            I ll chime in here too. Tom has good advice. When I bought my 40 Ah TS cells the price was $63.00 per cell. Since the 60 Ah cells are now about the same
            Message 5 of 29 , Dec 4, 2012
            • 0 Attachment
              I'll chime in here too. Tom has good advice. When I bought my 40 Ah TS cells the price was $63.00 per cell. Since the 60 Ah cells are now about the same price  as what I paid 4 years ago it makes no sense to use a 40 Ah cell today unless you live in a hot climate and on an island,  the sag is bad with the 40 Ah in cold weather. The only reason I have not upgraded is because they are still performing and as I mentioned before as a solar powered vehicle the smaller pack works well, also I want to see how long they will last. Right now it appears the car may fail before the batteries, got some switching issues going on. So my advice is go with the 60Ah unless you must drive longer distances then go with what ever you can afford.
              Bouty  


              ________________________________
              From: "theoldcars@..." <theoldcars@...>
              To: solectria_ev@yahoogroups.com
              Sent: Monday, December 3, 2012 9:47 PM
              Subject: Re: [solectria_ev] Thermal Management System

               
              Just a word of warning

              The CALB cells are not rated as many sellers on the Internet are showing 3C
              and 4C on their web sites. The SE series was rated by CALB at 1C and many
              have put them under loads of 3C or 4C. There is no data that I am aware of
              that shows cycle life under these higher C rates but it will be less.

              The new CA series which are also called the gray cells are rated at 2C by
              CALB.

              If your going to put a higher C rate on a CALB cell I would recommend it be
              the CA series.

              CALB for the most part has stopped selling the SE series except for a few
              sizes. The demand for the SE series has almost totally gone away with the
              release of the CA series.

              Jack from EVTV gives out some off some really off the wall advise and
              information. While some of what he does is good he also chimes in with baseless
              comments or beliefs that have no merit.

              On the 40Ah cells your going to see far more voltage sag under load. Cycle
              life would be less but as you point out its going to be a savings
              regardless over lead. I would highly recommend the CA 60Ah cells. The 60Ah cells
              hold their voltage very well. I know of one person who parallel two 40Ah of
              SE40 and their voltage sags more then a pack of 60Ah CA cells in series.

              Don Blazer


              In a message dated 12/3/2012 8:34:09 A.M. Pacific Standard Time,
              mailto:ev64bug%40yahoo.com writes:

              I have one question for Bouty:
              How many miles do you have on your pack?

              One question for the group:
              Does anyone have the dimension for the inside of the front battery box?

              I'm really interesting in Bouty's configuration. After 7 years and 22,000
              miles my poor old Pb pack is on it's last legs. I'm able to get 22 to
              24Ahrs out of the pack which is enough for a round trip to work and a very short
              side trip. Since the pack is fairly weak it takes 1.5 to 1.6Ahr per mile.
              I'm trying to hold out until summer for my switch to lithium when the
              weather is a little better and I have my battery monitor tested out. I'm
              interested in putting 49 40Ahr CALB "grey" cells (CA40BFI) for a couple of
              reasons:

              1. If my measurements are correct the complete pack should fit in the
              front battery box in a 7x7 array. By moving the charger up front all the 156V
              wiring will be under the hood with a very short run between the pack and
              the controller.

              2. The pack cost
              is comparable to if not cheaper than the Deka equivalent. 40Ahr CALBs are
              around $55 each. 49 x $55 = $2,695 before tax and shipping. 13 Deka
              batteries would have to be $207 just to be comparable ($2,695 / 13 = $207 approx.)

              3. My car will be shedding 661lb. The CALB cells at 3.3lb each x 49 = 161
              lb vs the 822lb (63.2lb x 13) of the current pack. I'm probably going to
              have to find the original springs for the Geo, otherwise the car will feel
              like it is permanently going down a hill.

              4. The "blue" CALBs (SE40AHA) already have fantastic C ratings and the
              "grey" cells have better cold weather performance. The max current of the
              force at around 240A dc should be no problem for the 40Ahr cells, they should
              be able to handle C6. There is some interesting test data on the cells:
              _http://blog.evtv.me/2012/06/battery-jump-shift/_
              (http://blog.evtv.me/2012/06/battery-jump-shift/)

              I know the general consensus is that 60 Ahr or 100 Ahr is preferable, but
              I've been logging all my driving for the past 7 years, most days I use
              between 16Ahrs and 20Ahrs and only a few times did I even come close to 35Ahrs.

              ________________________________
              From: d. Bouton Baldridge <mailto:_cfrkeepr%40yahoo.com_
              (mailto:mailto:cfrkeepr%40yahoo.com) >
              To: "mailto:_solectria_ev%40yahoogroups.com_ (mailto:mailto:solectria_ev%40yahoogroups.com) "
              <mailto:_solectria_ev%40yahoogroups.com_ (mailto:mailto:solectria_ev%40yahoogroups.com) >
              Sent: Sunday, December 2, 2012 7:26 AM
              Subject: Re: [solectria_ev] Thermal Management System

              Hi Wade,
              In my opinion, the balance thing has been greatly over blown and your re
              adings are perefectly acceptable especially after using so much capacity
              having only +/-.1 v or so from the mean is fantastic. The big thing is avoiding
              going beyond the knees and your system seems to be working just fine doing
              that. As for the Ahmeter issue, It has been my experience that voltage is
              not a reliable means for determining capacity. In my case I have found the
              reaching the limiting voltage was caused by the pack warming up; for me it
              was the sun. Now that the ambient temperature is lower in the winter season
              my charge resets closer to zero, but in summer it stops on the plus side
              by .1 ah each cycle when the outside temp is above 80 degrees. My guess for
              you is that when you charge for a few hours, the pack temp increases higher
              than when you were driving and the voltage is slightly higher as a result
              this stops the charger earlier than
              the previous Ahour
              reading. I am not sure if this is happening as a function of breaking in
              or aging. But it was not an issue with lead since it woul be overcharged
              routinely and had the automatic reset. I am a few months shy of 4 years and
              this slight precession is only an annoyance it has not seemed to impact the
              utility of my pack. Since I have a pretty long warm season I would just
              occasionaly reset the Ah meter to zero just so I wouldn't have to remember
              every time. Now that my cells are getting twice as old as any Pb pack would
              last, I am getting into new territory for longevity and at some point I might
              find some of these answers, but for now I am saying congratulation on your
              project FWIW,
              Bouty

              ________________________________
              From: Wade Perry <mailto:_perrypeas%40gmail.com_ (mailto:mailto:perrypeas%40gmail.com) >
              To: mailto:_solectria_ev%40yahoogroups.com_ (mailto:mailto:solectria_ev%40yahoogroups.com)
              Sent: Sunday, December 2, 2012 1:47 AM
              Subject: [solectria_ev] Thermal Management System

              Greetings all- I've driven over 1,000 miles on lithium now.

              I drove a fair bit today, it was mostly empty when I was coming back home
              from the last errand so I thought I'd take the long way home and discharge
              a bit more than I usually do. Until today the maximum I'd taken out is
              probably around 45 Ahr. I had set my limit around 50 to be safe.
              So after I got home I drove the block a few times with the heater on. Went
              well past 50. I measured pack voltage and some individual cells while I
              did this and felt fairly safe as I was getting down towards the bottom.
              Finally drove it around one last time in econ with no heater and it was
              around 57.5 when I was done. Then I ran the heater by itself to get it to
              59. Took the voltage on each cell.
              Made a new column to my battery balancing spreadsheet, it's here-
              _https://docs.google.com/spreadsheet/pub?key=0An5nm8itUMMcdHhQV3RsSUdfbzRTQk
              FlNmtaSy05MHc&output=html_
              (https://docs.google.com/spreadsheet/pub?key=0An5nm8itUMMcdHhQV3RsSUdfbzRTQkFlNmtaSy05MHc&output=html)

              The cells were springing back as I was measuring them. When I was done I
              went back and measured CK, where I'd started measuring the pack. it was
              .04 volts higher than I'd written down the first time. By the time I was
              finishing measuring, all the cells were coming in around 3.04 or 3.05. So
              they're reasonably well balanced.

              One cell stands out. JA. It measured 2.93 when its adjacent cells were
              measuring an entire ~0.10 volt higher. I haven't figured it out yet.
              Other than it happens to be the one that I noticed arrived from the
              factory at 4.23% below 50% SOC. You can see that on the sheet. It stood
              out at the time because all the other cells came in at 1 or 2% over 50.
              This was the only one that was below, and by a fair amount.

              Anyway then I ran the heater some more, watching JA in particular. It
              would have been cool to have a graph of all the cells at once. But they
              were falling off quite quickly. Some dipped down to 2.75 or so. JA dipped
              all the way down to 2.50. But I discharged down to a full 60.00 Ahr on my
              counter! Finished with a pack voltage of around 160. (which was
              undoubtedly springing up also. I didn't wait around to check but plugged
              in the charger so I can drive again tomorrow)

              This is great, because I had feared I was losing capacity permanently by
              charging below freezing. I'd hoped this wasn't the case, but was concerned
              because on especially cold days there'd be +1.00 or +2.00 Ahr still left on
              the counter when the charger shut off. Warmer days I'd be back to -0.14 or
              something like that. I'd been worried that I was gradually damaging the
              cells.

              Apparently I'm not. Or at least not to the extent I'd feared. This is
              with a battery box that's not even put together yet- the 60 Ahr cells are
              taller than the gels I took out, so when I finally do get things put
              together properly, I'll need to shim the cover over the battery box. Right
              now it rests on top of the cells, so there's probably a 1" space all
              around, letting cold air in. I did put in a 60watt incandescent light bulb
              back there to keep things warmer (and bright and cheery) in the battery
              box, whenever the car's plugged in.

              So. What I'd really like to do is hook up the Solectria heating mats to AC
              power, so I can be more setup for winter. I myself took it apart back in
              August, but obviously didn't pay much attention to what I was doing. I've
              searched this list repeatedly but can't find anything that talks about
              where the AC power hooks up to the heaters / sensors... Can anyone point
              me to a resource about this?

              Thanks for the help!

              Wade Perry
              1998 Force
              56 CALB CA 60 Ahr

              [Non-text portions of this message have been removed]

              [Non-text portions of this message have been removed]

              [Non-text portions of this message have been removed]

              [Non-text portions of this message have been removed]




              [Non-text portions of this message have been removed]
            • d. Bouton Baldridge
              Oh I forgot to mention, I had been told by a Sinopoly (formly TS) dealer that TS and SkyEnergy (Calb) originally were the two primary cell makers, and Sky
              Message 6 of 29 , Dec 4, 2012
              • 0 Attachment
                Oh I forgot to mention, I had been told by a Sinopoly (formly TS) dealer that TS and SkyEnergy (Calb) originally were the two primary cell makers, and Sky (Calb) made the cells for their military so they were quite rugged could provide serious current, but that they had a shorter life than the TS. I have not used any Calbs, but I can attest to the TSs since I have at least 5 times brought the same group of cells back to life from 0v. Not on purpose mind you. My guess is that Calb has probably improved their product to give longer life with their new line, it is obvious that they have not been stingy with capacity sometimes 15% higher than rating. which would seem good except if your batch of cells are not matched, just keep it between the knees! good luck.
                Bouty


                ________________________________
                From: "theoldcars@..." <theoldcars@...>
                To: solectria_ev@yahoogroups.com
                Sent: Monday, December 3, 2012 9:47 PM
                Subject: Re: [solectria_ev] Thermal Management System

                 
                Just a word of warning

                The CALB cells are not rated as many sellers on the Internet are showing 3C
                and 4C on their web sites. The SE series was rated by CALB at 1C and many
                have put them under loads of 3C or 4C. There is no data that I am aware of
                that shows cycle life under these higher C rates but it will be less.

                The new CA series which are also called the gray cells are rated at 2C by
                CALB.

                If your going to put a higher C rate on a CALB cell I would recommend it be
                the CA series.

                CALB for the most part has stopped selling the SE series except for a few
                sizes. The demand for the SE series has almost totally gone away with the
                release of the CA series.

                Jack from EVTV gives out some off some really off the wall advise and
                information. While some of what he does is good he also chimes in with baseless
                comments or beliefs that have no merit.

                On the 40Ah cells your going to see far more voltage sag under load. Cycle
                life would be less but as you point out its going to be a savings
                regardless over lead. I would highly recommend the CA 60Ah cells. The 60Ah cells
                hold their voltage very well. I know of one person who parallel two 40Ah of
                SE40 and their voltage sags more then a pack of 60Ah CA cells in series.

                Don Blazer


                In a message dated 12/3/2012 8:34:09 A.M. Pacific Standard Time,
                mailto:ev64bug%40yahoo.com writes:

                I have one question for Bouty:
                How many miles do you have on your pack?

                One question for the group:
                Does anyone have the dimension for the inside of the front battery box?

                I'm really interesting in Bouty's configuration. After 7 years and 22,000
                miles my poor old Pb pack is on it's last legs. I'm able to get 22 to
                24Ahrs out of the pack which is enough for a round trip to work and a very short
                side trip. Since the pack is fairly weak it takes 1.5 to 1.6Ahr per mile.
                I'm trying to hold out until summer for my switch to lithium when the
                weather is a little better and I have my battery monitor tested out. I'm
                interested in putting 49 40Ahr CALB "grey" cells (CA40BFI) for a couple of
                reasons:

                1. If my measurements are correct the complete pack should fit in the
                front battery box in a 7x7 array. By moving the charger up front all the 156V
                wiring will be under the hood with a very short run between the pack and
                the controller.

                2. The pack cost
                is comparable to if not cheaper than the Deka equivalent. 40Ahr CALBs are
                around $55 each. 49 x $55 = $2,695 before tax and shipping. 13 Deka
                batteries would have to be $207 just to be comparable ($2,695 / 13 = $207 approx.)

                3. My car will be shedding 661lb. The CALB cells at 3.3lb each x 49 = 161
                lb vs the 822lb (63.2lb x 13) of the current pack. I'm probably going to
                have to find the original springs for the Geo, otherwise the car will feel
                like it is permanently going down a hill.

                4. The "blue" CALBs (SE40AHA) already have fantastic C ratings and the
                "grey" cells have better cold weather performance. The max current of the
                force at around 240A dc should be no problem for the 40Ahr cells, they should
                be able to handle C6. There is some interesting test data on the cells:
                _http://blog.evtv.me/2012/06/battery-jump-shift/_
                (http://blog.evtv.me/2012/06/battery-jump-shift/)

                I know the general consensus is that 60 Ahr or 100 Ahr is preferable, but
                I've been logging all my driving for the past 7 years, most days I use
                between 16Ahrs and 20Ahrs and only a few times did I even come close to 35Ahrs.

                ________________________________
                From: d. Bouton Baldridge <mailto:_cfrkeepr%40yahoo.com_
                (mailto:mailto:cfrkeepr%40yahoo.com) >
                To: "mailto:_solectria_ev%40yahoogroups.com_ (mailto:mailto:solectria_ev%40yahoogroups.com) "
                <mailto:_solectria_ev%40yahoogroups.com_ (mailto:mailto:solectria_ev%40yahoogroups.com) >
                Sent: Sunday, December 2, 2012 7:26 AM
                Subject: Re: [solectria_ev] Thermal Management System

                Hi Wade,
                In my opinion, the balance thing has been greatly over blown and your re
                adings are perefectly acceptable especially after using so much capacity
                having only +/-.1 v or so from the mean is fantastic. The big thing is avoiding
                going beyond the knees and your system seems to be working just fine doing
                that. As for the Ahmeter issue, It has been my experience that voltage is
                not a reliable means for determining capacity. In my case I have found the
                reaching the limiting voltage was caused by the pack warming up; for me it
                was the sun. Now that the ambient temperature is lower in the winter season
                my charge resets closer to zero, but in summer it stops on the plus side
                by .1 ah each cycle when the outside temp is above 80 degrees. My guess for
                you is that when you charge for a few hours, the pack temp increases higher
                than when you were driving and the voltage is slightly higher as a result
                this stops the charger earlier than
                the previous Ahour
                reading. I am not sure if this is happening as a function of breaking in
                or aging. But it was not an issue with lead since it woul be overcharged
                routinely and had the automatic reset. I am a few months shy of 4 years and
                this slight precession is only an annoyance it has not seemed to impact the
                utility of my pack. Since I have a pretty long warm season I would just
                occasionaly reset the Ah meter to zero just so I wouldn't have to remember
                every time. Now that my cells are getting twice as old as any Pb pack would
                last, I am getting into new territory for longevity and at some point I might
                find some of these answers, but for now I am saying congratulation on your
                project FWIW,
                Bouty

                ________________________________
                From: Wade Perry <mailto:_perrypeas%40gmail.com_ (mailto:mailto:perrypeas%40gmail.com) >
                To: mailto:_solectria_ev%40yahoogroups.com_ (mailto:mailto:solectria_ev%40yahoogroups.com)
                Sent: Sunday, December 2, 2012 1:47 AM
                Subject: [solectria_ev] Thermal Management System

                Greetings all- I've driven over 1,000 miles on lithium now.

                I drove a fair bit today, it was mostly empty when I was coming back home
                from the last errand so I thought I'd take the long way home and discharge
                a bit more than I usually do. Until today the maximum I'd taken out is
                probably around 45 Ahr. I had set my limit around 50 to be safe.
                So after I got home I drove the block a few times with the heater on. Went
                well past 50. I measured pack voltage and some individual cells while I
                did this and felt fairly safe as I was getting down towards the bottom.
                Finally drove it around one last time in econ with no heater and it was
                around 57.5 when I was done. Then I ran the heater by itself to get it to
                59. Took the voltage on each cell.
                Made a new column to my battery balancing spreadsheet, it's here-
                _https://docs.google.com/spreadsheet/pub?key=0An5nm8itUMMcdHhQV3RsSUdfbzRTQk
                FlNmtaSy05MHc&output=html_
                (https://docs.google.com/spreadsheet/pub?key=0An5nm8itUMMcdHhQV3RsSUdfbzRTQkFlNmtaSy05MHc&output=html)

                The cells were springing back as I was measuring them. When I was done I
                went back and measured CK, where I'd started measuring the pack. it was
                .04 volts higher than I'd written down the first time. By the time I was
                finishing measuring, all the cells were coming in around 3.04 or 3.05. So
                they're reasonably well balanced.

                One cell stands out. JA. It measured 2.93 when its adjacent cells were
                measuring an entire ~0.10 volt higher. I haven't figured it out yet.
                Other than it happens to be the one that I noticed arrived from the
                factory at 4.23% below 50% SOC. You can see that on the sheet. It stood
                out at the time because all the other cells came in at 1 or 2% over 50.
                This was the only one that was below, and by a fair amount.

                Anyway then I ran the heater some more, watching JA in particular. It
                would have been cool to have a graph of all the cells at once. But they
                were falling off quite quickly. Some dipped down to 2.75 or so. JA dipped
                all the way down to 2.50. But I discharged down to a full 60.00 Ahr on my
                counter! Finished with a pack voltage of around 160. (which was
                undoubtedly springing up also. I didn't wait around to check but plugged
                in the charger so I can drive again tomorrow)

                This is great, because I had feared I was losing capacity permanently by
                charging below freezing. I'd hoped this wasn't the case, but was concerned
                because on especially cold days there'd be +1.00 or +2.00 Ahr still left on
                the counter when the charger shut off. Warmer days I'd be back to -0.14 or
                something like that. I'd been worried that I was gradually damaging the
                cells.

                Apparently I'm not. Or at least not to the extent I'd feared. This is
                with a battery box that's not even put together yet- the 60 Ahr cells are
                taller than the gels I took out, so when I finally do get things put
                together properly, I'll need to shim the cover over the battery box. Right
                now it rests on top of the cells, so there's probably a 1" space all
                around, letting cold air in. I did put in a 60watt incandescent light bulb
                back there to keep things warmer (and bright and cheery) in the battery
                box, whenever the car's plugged in.

                So. What I'd really like to do is hook up the Solectria heating mats to AC
                power, so I can be more setup for winter. I myself took it apart back in
                August, but obviously didn't pay much attention to what I was doing. I've
                searched this list repeatedly but can't find anything that talks about
                where the AC power hooks up to the heaters / sensors... Can anyone point
                me to a resource about this?

                Thanks for the help!

                Wade Perry
                1998 Force
                56 CALB CA 60 Ahr

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