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  • #31
    Originally posted by dian View Post
    the charging voltage rose to 10.1v (1 amp). maybe there is hope.
    I have a battery that I have left connected for many months to a low current solar panel as a charger/maintainer, which puts out up to 20 volts at low current (a couple hundred milliamperes), in case that might resuscitate it. The battery had gotten low in charge state, and really should be replaced, but that has not been done yet, and meanwhile, it does not eat....

    Anyway, the charge voltage is all over the map. It has been as high as nearly 16V, and as low as 6V (it is a 12V battery), repeatedly. The battery is still not charging well, and I do not expect it to.

    Yours will probably tease you with gains but never get anywhere. Best to replace it.
    1601 2137 5683 1002 1437

    Keep eye on ball.
    Hashim Khan

    If you look closely at a digital signal, you find out it is really analog......

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    • #32
      Originally posted by eKretz View Post
      The shorted cells can be due to lead sulfate flaking off the plates and falling to the bottom of the battery, eventually piling up enough to connect two plates, or from lead sulfate building up on the plates with enough growth until two adjacent plates are bridged. Sometimes dropping the battery on concrete a few times (not from very high, maybe 6-12 inches) will bring them back for a little while, but usually not for long. The best way to prevent this as long as possible is to keep the battery on a float charger or battery tender. I have had batteries last 10 years when using one. The sulfation accelerates when battery voltage is depleted.
      the battery has been sitting on the charger still showing 10v. i turned it upside down, strapped it to a compressor motor and gave it a good workout. battery voltage dropped from 8v to 6v after the procedure so something must have happened. back on the charger, however, it went up to 10v as before and is staying there. so vibrating didnt help in this case.

      im through with epson salts and ac-welders, the latter actually has completely killed a battery before. fortunately i get $10 for it when buying a new one.

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      • #33
        What are you.....Stuck on Gilligan's Island?
        The Professor made a battery for the radio using some coconuts.
        Maybe you should try coconut juice.

        -Doozer
        DZER

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        • #34
          Originally posted by Doozer View Post
          What are you.....Stuck on Gilligan's Island?
          The Professor made a battery for the radio using some coconuts.
          Maybe you should try coconut juice.

          -Doozer
          Some parts of the world must be caught in a time loop.
          They are forever repeating the years of the Great Depression.

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          • #35
            Originally posted by reggie_obe View Post

            Some parts of the world must be caught in a time loop.
            They are forever repeating the years of the Great Depression.
            We did just have one a few years ago......... and are about to have another, maybe.

            But with batteries, I have never found that "wishing" it to get charged made any difference. Replace the sucker and get on with life.
            1601 2137 5683 1002 1437

            Keep eye on ball.
            Hashim Khan

            If you look closely at a digital signal, you find out it is really analog......

            Comment


            • #36
              as i said before, this was not about saving the battery but rather learning more about how it works and what happens to it when it fails. i thought that should have been clear.

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              • #37
                Which has been covered.

                Short story: Car batteries fail by one of several means, all of which lead to loss of capacity, which is the ultimate failure mode.

                1) they remain uncharged for a while, and the normal sulfated state of the uncharged battery is modified by the sulfate changing form to an "unavailable" form that will not readily participate in the reaction

                2) The sulfate/oxide material mechanically becomes dislodged, disconnecting from the plates and "hopefully" falling to the bottom, wher it is obviously "unavailable".

                3) cells become shorted, either from loose sulfate, or abnormal growth of the lead grid

                4) overcharging or mechanical damage causes parts of some plates to be weakened, break loose, and so become electrically disconnected and "unavailable".

                Those are the top failures I have seen. The only even theoretically fixable failure mode of the lot is sulfation, #1, and that fix is somewhat questionable, "recovering" maybe 20 to 50% of capacity in the usual case.

                "How they work" is easily available with an internet search.
                1601 2137 5683 1002 1437

                Keep eye on ball.
                Hashim Khan

                If you look closely at a digital signal, you find out it is really analog......

                Comment


                • #38
                  You might be interested to know that 80% of a lead-acid battery's voltage derives from relativistic effects of the electrons orbiting the massive lead nucleus. They must move at near light speed and thus have a much higher effective mass, which, presumably, means greater energy and higher cell voltage.

                  https://physics.aps.org/story/v27/st2

                  https://arxiv.org/pdf/1008.4872.pdf

                  Last edited by PStechPaul; 11-21-2020, 07:55 PM.
                  http://pauleschoen.com/pix/PM08_P76_P54.png
                  Paul , P S Technology, Inc. and MrTibbs
                  USA Maryland 21030

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                  • #39
                    hm, i wonder if lead is heavy because its electrons move so fast. must move even fasten in tungsten and gold.

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                    • #40
                      Originally posted by reggie_obe View Post

                      Some parts of the world must be caught in a time loop.
                      They are forever repeating the years of the Great Depression.
                      Pretty insightful.
                      Good to think about.
                      I believe you're right.

                      -D
                      DZER

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                      • #41
                        On a related note, the kid i bought my hybrid from basically lied about the hybrid battery being replaced, that was a great disappointment to the tune of a couple grand if id gone and replaced it,,, but took it all apart and learned how to cycle the NiMH sticks, I did have to buy some other replacement sticks and a smart charger/discharger - I got the pack up and running without the IMA (integraded motor assist) light coming on --- looks like im going to be able to squeak by for just a couple hundred bucks so yeah - depending on the batteries --- they can certainly be worth messing with,
                        I could have got a "reman" pack for about a grand, but all it would have been is what im already doing,,, plus i never would have learned anything...

                        these NiMH have memory, all they need is to be taken down to a certain level and recharged to their max, then cycled over and over - they regain capacity each time... well - some of them - others are just plain toast...

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