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Report on CALB Conversion

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  • Gordon Stallings
    I have been lazy about reporting to this group my experiences while converting my Force to CALB. HereÆs a quick summary followed by more detail. Summary: I
    Message 1 of 6 , Aug 23 8:57 PM
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      I have been lazy about reporting to this group my experiences while
      converting my Force to CALB. Here�s a quick summary followed by more
      detail.
      Summary:
      I converted my 1999 Force from the standard 13 gel lead-acid batteries
      to 56 lithium iron phosphate cells made by China Aviation Lithium
      Battery Co. (CALB). The conversion requires a lot of money and a lot
      of work. The result is a car that is 400 pounds lighter, much peppier,
      and which has a much greater range of travel on a charge.
      The major costs were for the CALB cells and for a replacement charger.
      My Force was equipped with the BC3KW charger which is not
      reprogrammable. So I bought a new Brusa NLG-5 charger.
      CALB cells: $7082. (February price)
      Cell links: $110.
      Brusa NLG-5: $1713.
      There were other small expenses, such as a USB-to-serial converter,
      foam for stabilizing the cells, computer cables, software, special
      grease for the electrical joints, etc. The total cost was more than
      $9000. This may not be the end of it, because I may eventually put in
      a BMS at an additional cost in excess of $2000.
      As I worked my way through this conversion, I was reminded of my
      experiences during the early days of hobby computing (1975-82): costs
      are high, information is in short supply, you need a number of
      specialized skills such as soldering and programming, and you�ve gotta
      be willing to deal with a lot of frustration. Consequently, I would
      not recommend this conversion to anyone except the serious hobbyist.
      As for me, I am glad that I did it.
      There are a few photos at:
      http://franstallings.com/GRS/Lithium/index.html
      --------------
      Now for the details (for those who are interested).
      I bought the CALB cells through Don Blazer, as several other Solectria
      owners have done. One cell arrived with a stripped positive pole. The
      battery company was not interested in replacing it. I found a
      machinist in town who was able to bottom-tap the cell. I weighed the
      various opinions that I found on the internet and finally decided to
      not install a BMS. The basic idea is to never get near the �knee� at
      the top of the charge curve, nor near the knee at the bottom of the
      discharge curve. Unlike lead-acid batteries, these lithium cells are
      not harmed by remaining only partially charged. It should be noted
      that the CALB manual states that all warrantee is void if the cells
      are used without a BMS!
      Through the generous help and advice of Tom Hudson, I bottom-balanced
      the cells to 2.758V using two PowerLab chargers that Tom loaned to me.
      I installed 20 cells in the front compartment and 36 in the rear
      compartment. Each cell has an aluminum positive terminal and a copper
      negative terminal. I filed the oxide off the aluminum terminal of each
      cell and polished the copper terminal with steel wool. Then I vacuumed
      up the particles and used a special terminal paste designed to mate
      copper to aluminum. The copper post was connected �dry�. Tests showed
      that when charging at the 12.5A rate, the voltage drop at each
      terminal is below 1 mV (strap to terminal). So I am satisfied with all
      the connections.
      I was not certain that the BC3KW charger in the Force would charge the
      lithium pack without damaging it. And I did not have the equipment to
      test that charger�s performance with lithium. So I bought a new NLG5
      from EVTV at a reduced price. This unit required some assembly to make
      the proper connections. I�d never assembled an AMP watertight
      connector before. I included wiring to power the LEDs in the Solectria
      Charger Interface box. But it turns out this was wasted effort. The
      Brusa signal outputs are rather feeble, resulting in ambiguous
      patterns in the LEDs. Those LEDs are not needed anyway because the
      NLG5 charger displays the same information on its front panel (also
      rather feebly).
      Programming: The NLG5 requires an RS-232 interface for monitoring and
      programming. I borrowed a Windows 7 computer and bought an Easy Sync
      USB to RS-232 adapter. I also bought Hyperterminal, which wasn�t
      included with Windows 7. After some fooling around with port
      assignments, this worked fine for monitoring using Hyperterminal. But
      the programming software is balky, requiring several restarts before
      it sees the charger. The choices for charger settings are
      multidimensional. I used Tom Hudson�s �profile� as a starting point.
      Then made small adjustments until I was satisfied that the charger
      would not harm the cells. Tests on my pack convinced me that I should
      set the upper limit of charge voltage at 190V. So my charge �profile�
      is:
      * First, constant current (12.5A) until the pack voltage reaches 190V.
      * Then, constant voltage of 190V until the current drops below 1A.
      * Then, shut off charging and (feebly) light the �charging complete�
      LED on the car�s dashboard.
      The Brusa charger is an entirely different shape than the BC3KW. So I
      had to work out a way to mount it. Getting things to fit physically
      has never been my strong suit. But I followed Tom Hudson�s advice and
      built an adapter plate and used Velcro straps. It is secure and looks
      good.
      Precharge device: The Brusa manual said that the output capacitors in
      the NLG513 charger have such low equivalent series resistance that a
      precharge circuit is needed to cushion the inrush current when
      connecting the charger output cable to the battery pack. I built a
      simple precharge device. It is just a SPST switch with a 100 ohm 3W
      resistor across its terminals. This is placed in series with the wire
      from the charger that goes to the black connector under the hood.
      Before joining the ends of the black connector for the charger, turn
      the switch �off�. Then, a few seconds after connection, flip the
      switch on to short out the resistor. See the photos I put up. It
      probably is not a bad idea to also put such a device in series with
      the red connector for the DC-DC converter.
      Controller: I did not change the programming in the AC325 controller.
      Originally I had planned to do so. I built an adapter cable and bought
      an RS422 adapter. But when it was all together, it did not work and
      I�d had enough frustration for a while. Careful reading of back posts
      on the Solectria list indicates that the software will not work on
      Windows 7. So I would need to scrounge up an old Windows machine and
      build an RS-422 interface just for this purpose. I had no idea what
      parameters would need changing. I was pretty sure that I could get by
      without changing anything and so just buttoned up the controller and
      left it alone. The controller seems to work just fine with the new pack.
      The �battery monitor� device that I�d designed for the car is still
      working fine. So, I decided to modify it to monitor groups of four
      lithium cells. This meant monitoring 14 voltages instead of the 13
      that it was designed for. So I had to do a little wiring and some
      reprogramming. My old code was sparsely commented. So I had to figure
      out what I�d done 12 years ago. It�s all fixed now and I added more
      comments to make it easier �next time�. This display may give me a bit
      of warning if a cell is acting up.
      Operation: The rest voltage of the pack after charging is about 188V.
      After 75 miles of driving, the rest voltage is 182V. These values
      correspond to average cell voltages of 3.36 and 3.25. Both are well
      within the linear part of the battery curves. I�ve checked individual
      cell voltages and they are all tracking very well. A range of 75 miles
      is plenty for my needs. For your information, the pack voltage just
      after driving is about 1 volt lower than the reading a couple of hours
      later, which I call the "rest voltage".
      At first, I was concerned about regenerating into a charged pack. This
      is because the higher the charge current, the nearer the curve gets to
      the �knee�. I used to see this on my battery monitor when driving with
      the gel cells. Regen on a fully charged pack would cause the voltage
      of the weakest battery to climb to 16 or 17 volts. However, I don�t
      see this with my monitor now and so I sometimes leave regen on after
      charging. Also, I never get any �squeal� during regeneration into the
      lithiums.
      The summer heat sometimes causes the charger to quit early. I just
      plug in again later in the evening.
      The efficiency of the car also depends upon the temperature. When the
      air temperature is over 100, I am getting about .94 Ah/mile. At medium
      temperatures, I�m averaging about .77Ah/mi. These are closed-path
      numbers (from garage back to garage). For example, I just went 75.3
      miles and the meter reads 59.37. Efficiency = .79 Ah/mi. This is city
      driving on fairly flat terrain, temperature in the 90s and driving in
      Max Power with regeneration on. No air conditioning.
      Compare this with the efficiency of 1Ah/mi at 70F for the gels.
      With the CALBs, the Normal setting of the selector gives performance
      somewhat better than Max Power on the gels. I always drive with the
      selector in Max Power. So I am quite pleased with the pep. Because the
      pack has much less equivalent series resistance than the gels, the
      throttle feels very responsive.
      Conclusion:
      While I was in the midst of this conversion, a friend who bought my
      other Force wanted to change out his gels with new gels. The swap
      took only one day and cost him $2625. After a couple of days of
      conditioning, he was back on the road. Contrast that with the costly,
      lengthy process I went through!
      As I mentioned above, I feel that this conversion is not recommended
      except for the serious hobbyist. It�s expensive, time-consuming, and
      frustrating. But it is also very satisfying when finished.
      I may someday put in a BMS but only if this current arrangement gives
      trouble.

      --Gordon Stallings--

      [Non-text portions of this message have been removed]
    • Charles Bliss
      Nice write up. I looked at the pictures and don t see any compression on the cells. Perhaps I am the only one that has been near an expanded cell exploding,
      Message 2 of 6 , Aug 23 11:36 PM
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        Nice write up. I looked at the pictures and don't see any compression
        on the cells. Perhaps I am the only one that has been near an expanded
        cell exploding, but given that first hand experience, I got religion.
        Is there something special about the CALB cells that allows them to be
        installed without retaining them from expansion.

        On 8/23/2013 8:57 PM, Gordon Stallings wrote:
        > .........I converted my 1999 Force from the standard 13 gel lead-acid batteries
        > to 56 lithium iron phosphate cells made by China Aviation Lithium
        > Battery Co. (CALB). The conversion requires a lot of money and a lot
        > of work..............
      • Tom Hudson
        Thanks for the report, Gordon. Great detail! I am not getting the kind of efficiency you re getting, but I suspect I have some extra resistance in my wheels as
        Message 3 of 6 , Sep 4, 2013
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          Thanks for the report, Gordon. Great detail!

          I am not getting the kind of efficiency you're getting, but I suspect I have some extra
          resistance in my wheels as I can hear a fair amount of periodic noise coming from the
          wheels as I coast along -- I think I could do with a check of the wheel bearings. They
          started making a bit of a "grinding" noise at one point a while back after the car sat for
          a while in the garage -- actually, it was the year-long period when the car was idle and I
          was converting it to NiCD. The sound mostly cleared up after a few days of driving, but
          lately I can hear the sound as I drive, it bounces off nearby objects as I pass them and I
          can hear it pretty clearly. Sound = unnecessary friction = inefficiency.

          I'm due for a visual check of the battery packs, so when I do that I'll check my voltage
          drop at the battery straps and terminals under charge like you mention, and see if there
          is any loss happening there.

          We have been very happy with the CALB batteries as well -- yeah, it was a pain in the butt
          to do all the battery conditioning before loading them into the car, but I do think all
          the work was worth it. This conversion was NOTHING like the NiCD conversion, which
          involved designing and adding a complete liquid cooling system for the batteries --
          something that was necessary but added a huge number of potential failure points to the
          vehicle, and I found myself constantly checking to make sure that liquid was flowing
          through the system. At least the CALBs don't have that sort of issue.

          -Tom

          On 8/23/2013 10:57 PM, Gordon Stallings wrote:
          > I have been lazy about reporting to this group my experiences while
          > converting my Force to CALB. Here’s a quick summary followed by more
          > detail.
          > Summary:
          > I converted my 1999 Force from the standard 13 gel lead-acid batteries
          > to 56 lithium iron phosphate cells made by China Aviation Lithium
          > Battery Co. (CALB). The conversion requires a lot of money and a lot
          > of work. The result is a car that is 400 pounds lighter, much peppier,
          > and which has a much greater range of travel on a charge.
          > The major costs were for the CALB cells and for a replacement charger.
          > My Force was equipped with the BC3KW charger which is not
          > reprogrammable. So I bought a new Brusa NLG-5 charger.
          > CALB cells: $7082. (February price)
          > Cell links: $110.
          > Brusa NLG-5: $1713.
          > There were other small expenses, such as a USB-to-serial converter,
          > foam for stabilizing the cells, computer cables, software, special
          > grease for the electrical joints, etc. The total cost was more than
          > $9000. This may not be the end of it, because I may eventually put in
          > a BMS at an additional cost in excess of $2000.
          > As I worked my way through this conversion, I was reminded of my
          > experiences during the early days of hobby computing (1975-82): costs
          > are high, information is in short supply, you need a number of
          > specialized skills such as soldering and programming, and you’ve gotta
          > be willing to deal with a lot of frustration. Consequently, I would
          > not recommend this conversion to anyone except the serious hobbyist.
          > As for me, I am glad that I did it.
          > There are a few photos at:
          > http://franstallings.com/GRS/Lithium/index.html
          > --------------
          > Now for the details (for those who are interested).
          > I bought the CALB cells through Don Blazer, as several other Solectria
          > owners have done. One cell arrived with a stripped positive pole. The
          > battery company was not interested in replacing it. I found a
          > machinist in town who was able to bottom-tap the cell. I weighed the
          > various opinions that I found on the internet and finally decided to
          > not install a BMS. The basic idea is to never get near the “knee” at
          > the top of the charge curve, nor near the knee at the bottom of the
          > discharge curve. Unlike lead-acid batteries, these lithium cells are
          > not harmed by remaining only partially charged. It should be noted
          > that the CALB manual states that all warrantee is void if the cells
          > are used without a BMS!
          > Through the generous help and advice of Tom Hudson, I bottom-balanced
          > the cells to 2.758V using two PowerLab chargers that Tom loaned to me.
          > I installed 20 cells in the front compartment and 36 in the rear
          > compartment. Each cell has an aluminum positive terminal and a copper
          > negative terminal. I filed the oxide off the aluminum terminal of each
          > cell and polished the copper terminal with steel wool. Then I vacuumed
          > up the particles and used a special terminal paste designed to mate
          > copper to aluminum. The copper post was connected “dry”. Tests showed
          > that when charging at the 12.5A rate, the voltage drop at each
          > terminal is below 1 mV (strap to terminal). So I am satisfied with all
          > the connections.
          > I was not certain that the BC3KW charger in the Force would charge the
          > lithium pack without damaging it. And I did not have the equipment to
          > test that charger’s performance with lithium. So I bought a new NLG5
          > from EVTV at a reduced price. This unit required some assembly to make
          > the proper connections. I’d never assembled an AMP watertight
          > connector before. I included wiring to power the LEDs in the Solectria
          > Charger Interface box. But it turns out this was wasted effort. The
          > Brusa signal outputs are rather feeble, resulting in ambiguous
          > patterns in the LEDs. Those LEDs are not needed anyway because the
          > NLG5 charger displays the same information on its front panel (also
          > rather feebly).
          > Programming: The NLG5 requires an RS-232 interface for monitoring and
          > programming. I borrowed a Windows 7 computer and bought an Easy Sync
          > USB to RS-232 adapter. I also bought Hyperterminal, which wasn’t
          > included with Windows 7. After some fooling around with port
          > assignments, this worked fine for monitoring using Hyperterminal. But
          > the programming software is balky, requiring several restarts before
          > it sees the charger. The choices for charger settings are
          > multidimensional. I used Tom Hudson’s “profile” as a starting point.
          > Then made small adjustments until I was satisfied that the charger
          > would not harm the cells. Tests on my pack convinced me that I should
          > set the upper limit of charge voltage at 190V. So my charge “profile”
          > is:
          > * First, constant current (12.5A) until the pack voltage reaches 190V.
          > * Then, constant voltage of 190V until the current drops below 1A.
          > * Then, shut off charging and (feebly) light the “charging complete”
          > LED on the car’s dashboard.
          > The Brusa charger is an entirely different shape than the BC3KW. So I
          > had to work out a way to mount it. Getting things to fit physically
          > has never been my strong suit. But I followed Tom Hudson’s advice and
          > built an adapter plate and used Velcro straps. It is secure and looks
          > good.
          > Precharge device: The Brusa manual said that the output capacitors in
          > the NLG513 charger have such low equivalent series resistance that a
          > precharge circuit is needed to cushion the inrush current when
          > connecting the charger output cable to the battery pack. I built a
          > simple precharge device. It is just a SPST switch with a 100 ohm 3W
          > resistor across its terminals. This is placed in series with the wire
          > from the charger that goes to the black connector under the hood.
          > Before joining the ends of the black connector for the charger, turn
          > the switch “off”. Then, a few seconds after connection, flip the
          > switch on to short out the resistor. See the photos I put up. It
          > probably is not a bad idea to also put such a device in series with
          > the red connector for the DC-DC converter.
          > Controller: I did not change the programming in the AC325 controller.
          > Originally I had planned to do so. I built an adapter cable and bought
          > an RS422 adapter. But when it was all together, it did not work and
          > I’d had enough frustration for a while. Careful reading of back posts
          > on the Solectria list indicates that the software will not work on
          > Windows 7. So I would need to scrounge up an old Windows machine and
          > build an RS-422 interface just for this purpose. I had no idea what
          > parameters would need changing. I was pretty sure that I could get by
          > without changing anything and so just buttoned up the controller and
          > left it alone. The controller seems to work just fine with the new pack.
          > The “battery monitor” device that I’d designed for the car is still
          > working fine. So, I decided to modify it to monitor groups of four
          > lithium cells. This meant monitoring 14 voltages instead of the 13
          > that it was designed for. So I had to do a little wiring and some
          > reprogramming. My old code was sparsely commented. So I had to figure
          > out what I’d done 12 years ago. It’s all fixed now and I added more
          > comments to make it easier “next time”. This display may give me a bit
          > of warning if a cell is acting up.
          > Operation: The rest voltage of the pack after charging is about 188V.
          > After 75 miles of driving, the rest voltage is 182V. These values
          > correspond to average cell voltages of 3.36 and 3.25. Both are well
          > within the linear part of the battery curves. I’ve checked individual
          > cell voltages and they are all tracking very well. A range of 75 miles
          > is plenty for my needs. For your information, the pack voltage just
          > after driving is about 1 volt lower than the reading a couple of hours
          > later, which I call the "rest voltage".
          > At first, I was concerned about regenerating into a charged pack. This
          > is because the higher the charge current, the nearer the curve gets to
          > the “knee”. I used to see this on my battery monitor when driving with
          > the gel cells. Regen on a fully charged pack would cause the voltage
          > of the weakest battery to climb to 16 or 17 volts. However, I don’t
          > see this with my monitor now and so I sometimes leave regen on after
          > charging. Also, I never get any “squeal” during regeneration into the
          > lithiums.
          > The summer heat sometimes causes the charger to quit early. I just
          > plug in again later in the evening.
          > The efficiency of the car also depends upon the temperature. When the
          > air temperature is over 100, I am getting about .94 Ah/mile. At medium
          > temperatures, I’m averaging about .77Ah/mi. These are closed-path
          > numbers (from garage back to garage). For example, I just went 75.3
          > miles and the meter reads 59.37. Efficiency = .79 Ah/mi. This is city
          > driving on fairly flat terrain, temperature in the 90s and driving in
          > Max Power with regeneration on. No air conditioning.
          > Compare this with the efficiency of 1Ah/mi at 70F for the gels.
          > With the CALBs, the Normal setting of the selector gives performance
          > somewhat better than Max Power on the gels. I always drive with the
          > selector in Max Power. So I am quite pleased with the pep. Because the
          > pack has much less equivalent series resistance than the gels, the
          > throttle feels very responsive.
          > Conclusion:
          > While I was in the midst of this conversion, a friend who bought my
          > other Force wanted to change out his gels with new gels. The swap
          > took only one day and cost him $2625. After a couple of days of
          > conditioning, he was back on the road. Contrast that with the costly,
          > lengthy process I went through!
          > As I mentioned above, I feel that this conversion is not recommended
          > except for the serious hobbyist. It’s expensive, time-consuming, and
          > frustrating. But it is also very satisfying when finished.
          > I may someday put in a BMS but only if this current arrangement gives
          > trouble.
          >
          > --Gordon Stallings--
          >
          > [Non-text portions of this message have been removed]
          >
          >
          >
          > ------------------------------------
          >
          > Yahoo! Groups Links
          >
          >
          >
          >
          >
          >

          --
          Thomas Hudson
          http://portev.org -- Electric Vehicles, Solar Power & More
          http://klanky.com -- Animation Projects
        • Chandler Chip
          Concerning the wheel noise, check your front brake calipers. I and others have had that noise and drag issue before. Chip Chandler cchandler66@roadrunner.com
          Message 4 of 6 , Sep 4, 2013
          • 0 Attachment
            Concerning the wheel noise, check your front brake calipers. I and others have had that noise and drag issue before.

            Chip Chandler
            cchandler66@...

            On Sep 4, 2013, at 9:47 AM, Tom Hudson <tdhudson@...> wrote:

            > Thanks for the report, Gordon. Great detail!
            >
            > I am not getting the kind of efficiency you're getting, but I suspect I have some extra
            > resistance in my wheels as I can hear a fair amount of periodic noise coming from the
            > wheels as I coast along -- I think I could do with a check of the wheel bearings. They
            > started making a bit of a "grinding" noise at one point a while back after the car sat for
            > a while in the garage -- actually, it was the year-long period when the car was idle and I
            > was converting it to NiCD. The sound mostly cleared up after a few days of driving, but
            > lately I can hear the sound as I drive, it bounces off nearby objects as I pass them and I
            > can hear it pretty clearly. Sound = unnecessary friction = inefficiency.
            >
            > I'm due for a visual check of the battery packs, so when I do that I'll check my voltage
            > drop at the battery straps and terminals under charge like you mention, and see if there
            > is any loss happening there.
            >
            > We have been very happy with the CALB batteries as well -- yeah, it was a pain in the butt
            > to do all the battery conditioning before loading them into the car, but I do think all
            > the work was worth it. This conversion was NOTHING like the NiCD conversion, which
            > involved designing and adding a complete liquid cooling system for the batteries --
            > something that was necessary but added a huge number of potential failure points to the
            > vehicle, and I found myself constantly checking to make sure that liquid was flowing
            > through the system. At least the CALBs don't have that sort of issue.
            >
            > -Tom
            >
            > On 8/23/2013 10:57 PM, Gordon Stallings wrote:
            >> I have been lazy about reporting to this group my experiences while
            >> converting my Force to CALB. Here’s a quick summary followed by more
            >> detail.
            >> Summary:
            >> I converted my 1999 Force from the standard 13 gel lead-acid batteries
            >> to 56 lithium iron phosphate cells made by China Aviation Lithium
            >> Battery Co. (CALB). The conversion requires a lot of money and a lot
            >> of work. The result is a car that is 400 pounds lighter, much peppier,
            >> and which has a much greater range of travel on a charge.
            >> The major costs were for the CALB cells and for a replacement charger.
            >> My Force was equipped with the BC3KW charger which is not
            >> reprogrammable. So I bought a new Brusa NLG-5 charger.
            >> CALB cells: $7082. (February price)
            >> Cell links: $110.
            >> Brusa NLG-5: $1713.
            >> There were other small expenses, such as a USB-to-serial converter,
            >> foam for stabilizing the cells, computer cables, software, special
            >> grease for the electrical joints, etc. The total cost was more than
            >> $9000. This may not be the end of it, because I may eventually put in
            >> a BMS at an additional cost in excess of $2000.
            >> As I worked my way through this conversion, I was reminded of my
            >> experiences during the early days of hobby computing (1975-82): costs
            >> are high, information is in short supply, you need a number of
            >> specialized skills such as soldering and programming, and you’ve gotta
            >> be willing to deal with a lot of frustration. Consequently, I would
            >> not recommend this conversion to anyone except the serious hobbyist.
            >> As for me, I am glad that I did it.
            >> There are a few photos at:
            >> http://franstallings.com/GRS/Lithium/index.html
            >> --------------
            >> Now for the details (for those who are interested).
            >> I bought the CALB cells through Don Blazer, as several other Solectria
            >> owners have done. One cell arrived with a stripped positive pole. The
            >> battery company was not interested in replacing it. I found a
            >> machinist in town who was able to bottom-tap the cell. I weighed the
            >> various opinions that I found on the internet and finally decided to
            >> not install a BMS. The basic idea is to never get near the “knee” at
            >> the top of the charge curve, nor near the knee at the bottom of the
            >> discharge curve. Unlike lead-acid batteries, these lithium cells are
            >> not harmed by remaining only partially charged. It should be noted
            >> that the CALB manual states that all warrantee is void if the cells
            >> are used without a BMS!
            >> Through the generous help and advice of Tom Hudson, I bottom-balanced
            >> the cells to 2.758V using two PowerLab chargers that Tom loaned to me.
            >> I installed 20 cells in the front compartment and 36 in the rear
            >> compartment. Each cell has an aluminum positive terminal and a copper
            >> negative terminal. I filed the oxide off the aluminum terminal of each
            >> cell and polished the copper terminal with steel wool. Then I vacuumed
            >> up the particles and used a special terminal paste designed to mate
            >> copper to aluminum. The copper post was connected “dry”. Tests showed
            >> that when charging at the 12.5A rate, the voltage drop at each
            >> terminal is below 1 mV (strap to terminal). So I am satisfied with all
            >> the connections.
            >> I was not certain that the BC3KW charger in the Force would charge the
            >> lithium pack without damaging it. And I did not have the equipment to
            >> test that charger’s performance with lithium. So I bought a new NLG5
            >> from EVTV at a reduced price. This unit required some assembly to make
            >> the proper connections. I’d never assembled an AMP watertight
            >> connector before. I included wiring to power the LEDs in the Solectria
            >> Charger Interface box. But it turns out this was wasted effort. The
            >> Brusa signal outputs are rather feeble, resulting in ambiguous
            >> patterns in the LEDs. Those LEDs are not needed anyway because the
            >> NLG5 charger displays the same information on its front panel (also
            >> rather feebly).
            >> Programming: The NLG5 requires an RS-232 interface for monitoring and
            >> programming. I borrowed a Windows 7 computer and bought an Easy Sync
            >> USB to RS-232 adapter. I also bought Hyperterminal, which wasn’t
            >> included with Windows 7. After some fooling around with port
            >> assignments, this worked fine for monitoring using Hyperterminal. But
            >> the programming software is balky, requiring several restarts before
            >> it sees the charger. The choices for charger settings are
            >> multidimensional. I used Tom Hudson’s “profile” as a starting point.
            >> Then made small adjustments until I was satisfied that the charger
            >> would not harm the cells. Tests on my pack convinced me that I should
            >> set the upper limit of charge voltage at 190V. So my charge “profile”
            >> is:
            >> * First, constant current (12.5A) until the pack voltage reaches 190V.
            >> * Then, constant voltage of 190V until the current drops below 1A.
            >> * Then, shut off charging and (feebly) light the “charging complete”
            >> LED on the car’s dashboard.
            >> The Brusa charger is an entirely different shape than the BC3KW. So I
            >> had to work out a way to mount it. Getting things to fit physically
            >> has never been my strong suit. But I followed Tom Hudson’s advice and
            >> built an adapter plate and used Velcro straps. It is secure and looks
            >> good.
            >> Precharge device: The Brusa manual said that the output capacitors in
            >> the NLG513 charger have such low equivalent series resistance that a
            >> precharge circuit is needed to cushion the inrush current when
            >> connecting the charger output cable to the battery pack. I built a
            >> simple precharge device. It is just a SPST switch with a 100 ohm 3W
            >> resistor across its terminals. This is placed in series with the wire
            >> from the charger that goes to the black connector under the hood.
            >> Before joining the ends of the black connector for the charger, turn
            >> the switch “off”. Then, a few seconds after connection, flip the
            >> switch on to short out the resistor. See the photos I put up. It
            >> probably is not a bad idea to also put such a device in series with
            >> the red connector for the DC-DC converter.
            >> Controller: I did not change the programming in the AC325 controller.
            >> Originally I had planned to do so. I built an adapter cable and bought
            >> an RS422 adapter. But when it was all together, it did not work and
            >> I’d had enough frustration for a while. Careful reading of back posts
            >> on the Solectria list indicates that the software will not work on
            >> Windows 7. So I would need to scrounge up an old Windows machine and
            >> build an RS-422 interface just for this purpose. I had no idea what
            >> parameters would need changing. I was pretty sure that I could get by
            >> without changing anything and so just buttoned up the controller and
            >> left it alone. The controller seems to work just fine with the new pack.
            >> The “battery monitor” device that I’d designed for the car is still
            >> working fine. So, I decided to modify it to monitor groups of four
            >> lithium cells. This meant monitoring 14 voltages instead of the 13
            >> that it was designed for. So I had to do a little wiring and some
            >> reprogramming. My old code was sparsely commented. So I had to figure
            >> out what I’d done 12 years ago. It’s all fixed now and I added more
            >> comments to make it easier “next time”. This display may give me a bit
            >> of warning if a cell is acting up.
            >> Operation: The rest voltage of the pack after charging is about 188V.
            >> After 75 miles of driving, the rest voltage is 182V. These values
            >> correspond to average cell voltages of 3.36 and 3.25. Both are well
            >> within the linear part of the battery curves. I’ve checked individual
            >> cell voltages and they are all tracking very well. A range of 75 miles
            >> is plenty for my needs. For your information, the pack voltage just
            >> after driving is about 1 volt lower than the reading a couple of hours
            >> later, which I call the "rest voltage".
            >> At first, I was concerned about regenerating into a charged pack. This
            >> is because the higher the charge current, the nearer the curve gets to
            >> the “knee”. I used to see this on my battery monitor when driving with
            >> the gel cells. Regen on a fully charged pack would cause the voltage
            >> of the weakest battery to climb to 16 or 17 volts. However, I don’t
            >> see this with my monitor now and so I sometimes leave regen on after
            >> charging. Also, I never get any “squeal” during regeneration into the
            >> lithiums.
            >> The summer heat sometimes causes the charger to quit early. I just
            >> plug in again later in the evening.
            >> The efficiency of the car also depends upon the temperature. When the
            >> air temperature is over 100, I am getting about .94 Ah/mile. At medium
            >> temperatures, I’m averaging about .77Ah/mi. These are closed-path
            >> numbers (from garage back to garage). For example, I just went 75.3
            >> miles and the meter reads 59.37. Efficiency = .79 Ah/mi. This is city
            >> driving on fairly flat terrain, temperature in the 90s and driving in
            >> Max Power with regeneration on. No air conditioning.
            >> Compare this with the efficiency of 1Ah/mi at 70F for the gels.
            >> With the CALBs, the Normal setting of the selector gives performance
            >> somewhat better than Max Power on the gels. I always drive with the
            >> selector in Max Power. So I am quite pleased with the pep. Because the
            >> pack has much less equivalent series resistance than the gels, the
            >> throttle feels very responsive.
            >> Conclusion:
            >> While I was in the midst of this conversion, a friend who bought my
            >> other Force wanted to change out his gels with new gels. The swap
            >> took only one day and cost him $2625. After a couple of days of
            >> conditioning, he was back on the road. Contrast that with the costly,
            >> lengthy process I went through!
            >> As I mentioned above, I feel that this conversion is not recommended
            >> except for the serious hobbyist. It’s expensive, time-consuming, and
            >> frustrating. But it is also very satisfying when finished.
            >> I may someday put in a BMS but only if this current arrangement gives
            >> trouble.
            >>
            >> --Gordon Stallings--
            >>
            >> [Non-text portions of this message have been removed]
            >>
            >>
            >>
            >> ------------------------------------
            >>
            >> Yahoo! Groups Links
            >>
            >>
            >>
            >>
            >>
            >>
            >
            > --
            > Thomas Hudson
            > http://portev.org -- Electric Vehicles, Solar Power & More
            > http://klanky.com -- Animation Projects
            >
            >
            >
            > ------------------------------------
            >
            > Yahoo! Groups Links
            >
            >
            >
          • Charles Bliss
            and Check your tire pressure and make sure the hub caps are fully pressed in. My car makes noise when either are incorrect.
            Message 5 of 6 , Sep 4, 2013
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              and Check your tire pressure and make sure the hub caps are fully pressed in.  My car makes noise when either are incorrect.
              On 9/4/2013 7:27 AM, Chandler Chip wrote:
               

              Concerning the wheel noise, check your front brake calipers. I and others have had that noise and drag issue before.

              Chip Chandler
              cchandler66@...

              On Sep 4, 2013, at 9:47 AM, Tom Hudson <tdhudson@...> wrote:


            • Gordon Stallings
              Tom, Concerning your rolling noise, you should suspect the CV joints. Mine were growling and would click during a sharp turn. I had a shop do the
              Message 6 of 6 , Sep 5, 2013
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                Tom,
                Concerning your rolling noise, you should suspect the CV joints. Mine
                were growling and would click during a sharp turn. I had a shop do
                the replacement. They re-used the existing non-standard shaft by
                putting on a new end. The repair was not perfect, though, because
                there is now a vibration during heavy acceleration.

                --Gordon--
                On Sep 4, 2013, at 8:47 AM, Tom Hudson wrote:

                > Thanks for the report, Gordon. Great detail!
                >
                > I am not getting the kind of efficiency you're getting, but I
                > suspect I have some extra
                > resistance in my wheels as I can hear a fair amount of periodic
                > noise coming from the
                > wheels as I coast along -- I think I could do with a check of the
                > wheel bearings. They
                > started making a bit of a "grinding" noise at one point a while back
                > after the car sat for
                > a while in the garage -- actually, it was the year-long period when
                > the car was idle and I
                > was converting it to NiCD. The sound mostly cleared up after a few
                > days of driving, but
                > lately I can hear the sound as I drive, it bounces off nearby
                > objects as I pass them and I
                > can hear it pretty clearly. Sound = unnecessary friction =
                > inefficiency.
                >
                > I'm due for a visual check of the battery packs, so when I do that
                > I'll check my voltage
                > drop at the battery straps and terminals under charge like you
                > mention, and see if there
                > is any loss happening there.
                >
                > We have been very happy with the CALB batteries as well -- yeah, it
                > was a pain in the butt
                > to do all the battery conditioning before loading them into the car,
                > but I do think all
                > the work was worth it. This conversion was NOTHING like the NiCD
                > conversion, which
                > involved designing and adding a complete liquid cooling system for
                > the batteries --
                > something that was necessary but added a huge number of potential
                > failure points to the
                > vehicle, and I found myself constantly checking to make sure that
                > liquid was flowing
                > through the system. At least the CALBs don't have that sort of issue.
                >
                > -Tom
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