Loading ...
Sorry, an error occurred while loading the content.

Re: [force_ev] Battery equalization story

Expand Messages
  • David Roden (Akron OH USA)
    1.270 is not bad for old batteries. 1.250 is not so good. Low voltage and SG are symptomatic of sulfation and/or positive grid degradation. How do those
    Message 1 of 11 , May 23, 2001
    View Source
    • 0 Attachment
      1.270 is not bad for old batteries. 1.250 is not so good. Low voltage
      and SG are symptomatic of sulfation and/or positive grid degradation.

      How do those cells look inside? (Wear safety glasses when you peek!) Is
      the electrolyte greyish when you suck it up in the hydrometer? Do the
      plates look like they have mold growing between them, sort of spreading
      them apart? Are the ends of the batteries bulging very much?

      When you have the eq charge running, are the cells with low SG gassing
      just as liberally as the ones with higher SG? If so, you may have gotten
      about all you can get out of them.

      If not, maybe you didn't equalize long enough. It can take several
      ~days~ of equalization to bring up chronically undercharged cells.
      Unfortunately you have to keep overcharging the fully-charged ones in
      order to keep enough current flowing through the undercharged cells.

      If you have some batteries in which ~all~ the cells are at high SG, it
      doesn't make sense to keep cooking them. I would try equalizing the
      batteries with lower cells separately with 12 volt chargers. You can
      keep poking at them that way for several days if you hold the current
      down to perhaps 2 amps and keep the electrolyte level up.


      David Roden - Akron, Ohio, USA
      1991 Solectria Force 144vac
      1991 Ford Escort Green/EV 128vdc
      1979 General Engines ElectroPed 24vdc
      1974 Honda Civic EV 96vdc
      1970 GE Elec-trak E15 36vdc
      = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
      Thou shalt not send me any thing which says unto thee, "send this to all
      thou knowest." Neither shalt thou send me any spam, lest I smite thee.
      = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
    • Tom Hudson
      What s the story with these cars with flooded batteries? Did they come with floodeds originally? I was under the impression that Solectria always used sealed
      Message 2 of 11 , May 23, 2001
      View Source
      • 0 Attachment
        What's the story with these cars with flooded batteries? Did they come with
        floodeds originally? I was under the impression that Solectria always used
        sealed batteries. If they originally had sealed batteries, did someone
        reprogram the charger profiles?

        Just curious...

        -Tom

        Thomas Hudson
        http://portdistrict5.org -- 5th District Aldermanic Website


        > -----Original Message-----
        > From: David Roden (Akron OH USA) [mailto:roden@...]
        > Sent: Wednesday, May 23, 2001 10:34 PM
        > To: force_ev@yahoogroups.com
        > Subject: Re: [force_ev] Battery equalization story
        >
        >
        > 1.270 is not bad for old batteries. 1.250 is not so good. Low voltage
        > and SG are symptomatic of sulfation and/or positive grid degradation.
        >
        > How do those cells look inside? (Wear safety glasses when you peek!) Is
        > the electrolyte greyish when you suck it up in the hydrometer? Do the
        > plates look like they have mold growing between them, sort of spreading
        > them apart? Are the ends of the batteries bulging very much?
        >
        > When you have the eq charge running, are the cells with low SG gassing
        > just as liberally as the ones with higher SG? If so, you may have gotten
        > about all you can get out of them.
        >
        > If not, maybe you didn't equalize long enough. It can take several
        > ~days~ of equalization to bring up chronically undercharged cells.
        > Unfortunately you have to keep overcharging the fully-charged ones in
        > order to keep enough current flowing through the undercharged cells.
        >
        > If you have some batteries in which ~all~ the cells are at high SG, it
        > doesn't make sense to keep cooking them. I would try equalizing the
        > batteries with lower cells separately with 12 volt chargers. You can
        > keep poking at them that way for several days if you hold the current
        > down to perhaps 2 amps and keep the electrolyte level up.
        >
        >
        > David Roden - Akron, Ohio, USA
        > 1991 Solectria Force 144vac
        > 1991 Ford Escort Green/EV 128vdc
        > 1979 General Engines ElectroPed 24vdc
        > 1974 Honda Civic EV 96vdc
        > 1970 GE Elec-trak E15 36vdc
        > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
        > Thou shalt not send me any thing which says unto thee, "send this to all
        > thou knowest." Neither shalt thou send me any spam, lest I smite thee.
        > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
        >
        > To unsubscribe from this group, send an email to:
        > force_ev-unsubscribe@egroups.com
        >
        >
        >
        > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
        >
        >
      • David Roden (Akron OH USA)
        ... The very first Forces were fitted with flooded Sears Diehards (really!). I think they used various brands of flooded batteries through about the 93
        Message 3 of 11 , May 23, 2001
        View Source
        • 0 Attachment
          On 23 May 2001, at 23:28, Tom Hudson wrote:

          > What's the story with these cars with flooded batteries?

          The very first Forces were fitted with flooded Sears Diehards (really!).
          I think they used various brands of flooded batteries through about the
          '93 models.

          It appears that for the most part flooded batteries did not give very
          good service. In particular, the Diehards (built at that time by Johnson
          Controls) seem to have been a somewhat unfortunate choice. The paperwork
          that came with my '91 Force (the very first Force ever built) indicated
          that APS, the original owner, replaced the pack several times, with most
          packs lasting less than 9 months. Of course this was in hot Arizona,
          which may have had something to do with the abysmal cycle life.

          Most of those early cars used BC-1000 chargers, presumably set up for the
          correct batteries. BC-1000, BTW, seems to have designated at least two
          different types of chargers, maybe more. One of them I saw appears to
          use an external charge control gadget in a Radio Shack-type builder's
          box.

          The one that came in my car was a BC-1000, but was not the original; it
          was a replacement 230 volt charger, probably from or for an E-10 pickup.
          It has a microprocessor-based charge control and what is apparently an RS-
          232 port for reprogramming (though I don't know how to talk to it and
          haven't put much into it since I don't use it). It's set up for the
          Hawkers that were in the car when I got it, but probably was originally
          programmed for flooded marine batteries.


          David Roden - Akron, Ohio, USA
          1991 Solectria Force 144vac
          1991 Ford Escort Green/EV 128vdc
          1979 General Engines ElectroPed 24vdc
          1974 Honda Civic EV 96vdc
          1970 GE Elec-trak E15 36vdc
          = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
          Thou shalt not send me any thing which says unto thee, "send this to all
          thou knowest." Neither shalt thou send me any spam, lest I smite thee.
          = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
        • umarc@hippogryph.com
          OK. I ve done a little more checking, and I find that most of the cells in my car have SG in the 1.250 range, and some even a bit lower. A few are up around
          Message 4 of 11 , May 25, 2001
          View Source
          • 0 Attachment
            OK. I've done a little more checking, and I find that most of the cells in
            my car have SG in the 1.250 range, and some even a bit lower. A few are up
            around 1.270, but not many.

            On Wed, 23 May 2001, David Roden (Akron OH USA) wrote:

            > How do those cells look inside? (Wear safety glasses when you peek!) Is
            > the electrolyte greyish when you suck it up in the hydrometer? Do the
            > plates look like they have mold growing between them, sort of spreading
            > them apart? Are the ends of the batteries bulging very much?

            The cells look fairly clean as far as I can tell. The electrolyte is
            clear, there's no "mold" that I can see, and the batteries are not bulging
            noticeably.

            > When you have the eq charge running, are the cells with low SG gassing
            > just as liberally as the ones with higher SG? If so, you may have gotten
            > about all you can get out of them.

            That I can't tell.

            > If not, maybe you didn't equalize long enough. It can take several
            > ~days~ of equalization to bring up chronically undercharged cells.

            I've decided to try another bout of equalization using an old brainless
            Solectria charger and three 10-ohm resistors in series. The voltage drop
            across 10 ohms is 6.7 volts, so the inflow current is 0.67 amps. The
            votage across the pack is 165; as I understand it I'm supposed to
            discontinue charging when that voltage ceases to increase.

            Is there any other test I can use to tell when I've equalized enough? I
            gather that opening the cells and doing SG tests while charging is a bad
            idea, but I suppose I could temporarily unplug the charger, test a few
            cells, then plug it back in.


            Rob Landry
            umarc@...
          • David Roden (Akron OH USA)
            ... If that s voltage measured while on charge, it s quite low. On a brand new 144v flooded pack, you should get close to 180 volts while the charger is still
            Message 5 of 11 , May 25, 2001
            View Source
            • 0 Attachment
              On 25 May 2001, at 21:58, umarc@... wrote:

              > The
              > votage across the pack is 165; as I understand it I'm supposed to
              > discontinue charging when that voltage ceases to increase.

              If that's voltage measured while on charge, it's quite low. On a brand
              new 144v flooded pack, you should get close to 180 volts while the
              charger is still connected and still charging. An old pack should hit
              around 173-175v.

              To see what's going on, you need either a true constant-current charger
              or a variable output charger and an accurate ammeter. If you don't
              measure voltage with the current at a defined value (I recommend 3 amps
              for the typical group 27 battery), variation in your house's line voltage
              will obscure what's actually happening to the batteries.

              The classic variable charger is a simple variac (variable
              autotransformer) and a bridge rectifier. You check it now and again by
              calibrating it to the current you've decided on (say 3 amps) and reading
              the voltage.

              When it stops rising, that's about all you'll get. If you take three
              readings an hour apart and see essentially no increase, call it quits.
              If you get to about 180 volts, you have really good batteries. More
              likely you'll top out at around 173-175v.

              However -- keep the batteries cool! As they heat up, the on-charge
              voltage actually drops. This confuses things.

              If the cells are seriously out of balance, it may take a very long time,
              as much as several days, for the voltage to stop rising. The increase
              goes slower and slower all the time because as you continue, fewer and
              fewer cells are still accepting charge and rising in voltage. The others
              are just gassing and heating up.

              If at the end of this round you still can't read much above 1.250 SG in
              most cells and/or you can't get the voltage measured while on charge to
              go over about 170v, it might be getting close to time for a new pack.


              David Roden - Akron, Ohio, USA
              1991 Solectria Force 144vac
              1991 Ford Escort Green/EV 128vdc
              1979 General Engines ElectroPed 24vdc
              1974 Honda Civic EV 96vdc
              1970 GE Elec-trak E15 36vdc
              = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
              Thou shalt not send me any thing which says unto thee, "send this to all
              thou knowest." Neither shalt thou send me any spam, lest I smite thee.
              = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
            • umarc@hippogryph.com
              ... That was the voltage I measured just after starting the charge; this morning it was at 171, and the current had gone down below 0.5 amp, so I bypassed one
              Message 6 of 11 , May 26, 2001
              View Source
              • 0 Attachment
                On Sat, 26 May 2001, David Roden (Akron OH USA) wrote:

                > If that's voltage measured while on charge, it's quite low.

                That was the voltage I measured just after starting the charge; this
                morning it was at 171, and the current had gone down below 0.5 amp, so I
                bypassed one of the series resistors, which brought it up above 0.6 amp.
                A couple of hours ago the voltage was up to 174 and the current down to
                0.58 amp; just now it was down to 173.8 and the current up to 0.6 amp, so
                I stopped charging and checked the specific gravity in several cells; all
                were up above 1.270 where before they'd been at 1.250. I've disconnected
                the charger and will now leave the car alone for a couple of days --
                Monday will be the first opportunity I have to drive it.

                At some point I'm going to have to go through all the batteries and check
                the water levels.

                > To see what's going on, you need either a true constant-current charger
                > or a variable output charger and an accurate ammeter. If you don't
                > measure voltage with the current at a defined value (I recommend 3 amps
                > for the typical group 27 battery), variation in your house's line voltage
                > will obscure what's actually happening to the batteries.

                With a 10-ohm resistor in series, all I had to do was measure the voltage
                drop across it and divide by 10 to get the current in amperes.

                Thanks.


                Rob
              • Tom Hudson
                I have the Solectria owner s website back up and running! The old web host is still offline due to problems getting their data line reconnected, so I decided
                Message 7 of 11 , May 27, 2001
                View Source
                • 0 Attachment
                  I have the Solectria owner's website back up and running! The old web host
                  is still offline due to problems getting their data line reconnected, so I
                  decided to set up my own domain, http://portev.org It's the Port
                  Washington Electric Vehicle Association. Technically, since my wife and I
                  own both the EVs in Port Washington, Wisconsin, it's legitimate. :-)

                  Any of you out there who would like to be included in the Solectria Owners
                  Website, please email me off-list and I'll get you added. There's no cost
                  or obligation -- I just want to get everyone listed, it's an informational
                  site so people can see how EV owners use their vehicles. Check it out and I
                  think you'll want to be listed.

                  Thanks,
                  -Tom

                  Thomas Hudson
                  http://portdistrict5.org -- 5th District Aldermanic Website
                  http://portev.org/solectria/ho -- Our Electric Vehicles
                  http://portev.org/solectria/ho/pvs.htm -- Solar Power
                  http://portev.org/solectria -- Solectria Owners Website
                  http://portgardenclub.org -- Port Washington Garden Club
                • Tom Hudson
                  ... Thanks for the update, Peter. True, the value should be tailpipe pollution-free miles -- I made a clarification on the index page of the website. Plus,
                  Message 8 of 11 , May 28, 2001
                  View Source
                  • 0 Attachment
                    > One small update for the blurb on my car on the owners website.
                    > I have now gone 12,000 miles. I don't think we can really say
                    > "pollution free" since there is pollution from the power plants.
                    > Perhaps that is another comparable phrase we can think up.

                    Thanks for the update, Peter. True, the value should be "tailpipe"
                    pollution-free miles -- I made a clarification on the index page of the
                    website. Plus, I now have a total of the miles on the index page. The
                    average fuel economy in the US is currently around 25 MPG, meaning on
                    average, for every mile driven by Americans, about a pound of pollution is
                    emitted. Presently, our small group on the website has 73,990 miles --
                    Eliminating almost 37 TONS of tailpipe emissions! Wow.

                    I'd like to get odometer updates from everyone on the website -- I don't
                    have any readings at all for some people and it would be cool to see how
                    many more miles we have logged.

                    -Tom

                    Thomas Hudson
                    http://portdistrict5.org -- 5th District Aldermanic Website
                    http://portev.org/solectria/ho -- Our Electric Vehicles
                    http://portev.org/solectria/ho/pvs.htm -- Solar Power
                    http://portev.org/solectria -- Solectria Owners Website
                    http://portgardenclub.org -- Port Washington Garden Club
                  • Gordon Stallings
                    ... I ve now driven over 5,000 miles in my Force. Gordon Stallings 1999 Solectria Force
                    Message 9 of 11 , May 29, 2001
                    View Source
                    • 0 Attachment
                      At 23:52 05/28/2001 -0500, you wrote:
                      >I'd like to get odometer updates from everyone on the website -- I don't
                      >have any readings at all for some people and it would be cool to see how
                      >many more miles we have logged.

                      I've now driven over 5,000 miles in my Force.

                      Gordon Stallings
                      1999 Solectria Force
                    Your message has been successfully submitted and would be delivered to recipients shortly.