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  • Please Help with EQ on batteries

    Hi guys,

    Just returned from Orlando, The battery on the small pond solar system seem need EQ. My helper told me last week after a cloudy day the inverter trip off in the morning when she come to work, I told her to turn off the inverter and plug the pump to the house system. after about 4 days bright sun without any consumption the battery still not fully charged, actually the SG reading on 3 of the 4 batteries are below 1,200. I think I need to do thoroughly EQ on these batteries to see if any different.

    My question is, if I don't want to use the generator or the grid (actually I have problem to use the grid as the inverter in this system doesn't have a charger, and the new charge I got I don't think it have the EQ feature).

    Can I charge the batteries in one day with a charge controller with higher voltage and continue the next day without using the batteries? I can separate the two bank and charge one bank at a time and the other another time. if the EQ can't finished one day, can I continue the next day? with out discharge it or I have to make it run through without stop?

    Thank you.

  • #2
    1) it's critical you get the batteries charged up quickly, before they are damaged. Even if you have to pull each one out and drive it to a gas station to get it charged. sitting low for a week may have very likely killed them.

    2) if you have grid power, how did you come to install a battery system? Renting a trencher is much less expensive than buying batteries. And now it's likely you are into a 2nd set of batteries.


    For us to give you a specific answer, we need to know what gear you have that you are trying to
    work with. ie

    Grundfos 10 SO5-9 with 3 wire Franklin motor (1/2hp 240V 1ph # 214505 ) on a timer for 3 hr noontime run - Runs off PV
    Powerfab poletop PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe battery | 15, Evergreen 205w "12V" PV | Midnight ePanel || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT
    Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister

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    • #3
      What I need to know if I can Equalize the batteries in steps as it should take longer than one day(sun day). if I have to EQ without stop then I will have to do it. But I if I can start to EQ and stop then continue next day without discharge the batteries.

      As for why I put in a battery system instead grid tie, very simple, cat and dog don't have the same luck, you guys enjoy a very cheap electrical rate and get good incentive and may get net metering. In Jamaica we don't get net metering and the rate is in between 45 to 55 US cent per KWH. and they pay us about 25 to 40% to what they charge us. and the grid have power cut all the times so Battery is the way to go in Jamaica. one good thing the installation fee is a lot cheaper in Jamaica.

      What I try to do is try to do all the washing and ironing and heavy load in the day and in the night I cut off almost everything except the TV and light, the refrigerators are turned off in the nights. It work out for me so far. I just try to understand how to deal with the batteries so try to get the most out of them.

      Thank you.

      Comment


      • #4
        Originally posted by paulcheung View Post
        What I need to know if I can Equalize the batteries in steps as it should take longer than one day(sun day). if I have to EQ without stop then I will have to do it. But I if I can start to EQ and stop then continue next day without discharge the batteries.

        As for why I put in a battery system instead grid tie, very simple, cat and dog don't have the same luck, you guys enjoy a very cheap electrical rate and get good incentive and may get net metering. In Jamaica we don't get net metering and the rate is in between 45 to 55 US cent per KWH. and they pay us about 25 to 40% to what they charge us. and the grid have power cut all the times so Battery is the way to go in Jamaica. one good thing the installation fee is a lot cheaper in Jamaica.

        What I try to do is try to do all the washing and ironing and heavy load in the day and in the night I cut off almost everything except the TV and light, the refrigerators are turned off in the nights. It work out for me so far. I just try to understand how to deal with the batteries so try to get the most out of them.

        Thank you.
        You can do the equalization in steps as long as you bring the batteries up to Float before starting each part of the EQ process. But it will be less efficient, requiring more total time at EQ voltage than if you do it all at once, and potentially making it more difficult for you to do the necessary monitoring of the results.

        This is one reason that doing EQ using PV in a working off grid system is just not practical.
        Use grid power if available, otherwise generator power for the EQ unless you can essentially turn off all loads once you get the batteries up to an SOC where you can start EQ.
        SunnyBoy 3000 US, 18 BP Solar 175B panels.

        Comment


        • #5
          Yes I can disconnect one bank battery at a time as it is two banks and each has it's own disconnect breaker. so I need to bring it to full charge first then do the EQ, but it won't be full charge as it is always under 1200 in SG readings.

          Thanks.

          Comment


          • #6
            Originally posted by paulcheung View Post
            Yes I can disconnect one bank battery at a time as it is two banks and each has it's own disconnect breaker. so I need to bring it to full charge first then do the EQ, but it won't be full charge as it is always under 1200 in SG readings.

            Thanks.
            If it is full charge (in the sense that the current with Float voltage is applied is near zero, and yet the SG is only 1.200), then unless your batteries were specifically formulated with a lower SG (for tropical use for example?) then you have gotten as close to full charge as you can get and should go ahead with the EQ to see what happens.
            But the most common reason for low SG at full charge is that sulfation has taken much the H2SO4 out of the electrolyte and no amount of charging will break up the hard lead sulfate crystals and make the batteries as good as new.
            You should consider yourself lucky if you get any improvement from EQ.

            Oh, BTW, a low SG reading at the top of the cell (the only place you can draw electrolyte from) could also be a sign of stratification. In that case a good gassing EQ could stir the electrolyte and let you see what the true state of the cells is.
            Last edited by inetdog; 03-15-2014, 04:13 PM.
            SunnyBoy 3000 US, 18 BP Solar 175B panels.

            Comment


            • #7
              Ok Thanks

              Comment


              • #8
                Originally posted by paulcheung View Post
                Ok Thanks
                You are welcome.
                Some of the same information has also been given on the "High Voltage Charging" thread.
                SunnyBoy 3000 US, 18 BP Solar 175B panels.

                Comment

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