Series vs Parallel to run 500w Fridge

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  • Dayrobber
    Member
    • Jul 2019
    • 40

    Series vs Parallel to run 500w Fridge

    I have 3 12v 100w panels in parallel running to 40 amp mppt to 4 12v 101ah batteries to my 2000 watt PSW Inverter. 115 degrees most of July,Southern California. My fridge/freezer at full load 600w and 6. 5 amps. Should I be wired Series or parallel at the panels?
  • PNPmacnab
    Solar Fanatic
    • Nov 2016
    • 425

    #2
    In theory it doesn't make any difference except for wire loss. If the runs are short and there is any possibility of shading, parallel would work better.

    Comment

    • Billybob9
      Junior Member
      • Aug 2019
      • 7

      #3
      500W fridge is a full size 18-22 cubic feet. Since the work time is only 15 minutes per hour when cycling at set temperature, your in the ballpark to make it through the night unless a cloudy day leaves you with an under charged battery bank. Then your Inverter will shut off and you will need to reset in the morning. No problem just keep some water bottles in those empty spaces to maintain temperature stability. I did this for 5 years but changed to a 24vdc system as it was a little bit more stable. Four 6v golf cart batteries in series = 24vdc. Two 160W panels in series = 320W and 24vdc . Doing 2 strings made it a 640W system and better to make it through the night starting with a full charge.

      Comment

      • Dayrobber
        Member
        • Jul 2019
        • 40

        #4
        Thanks guys. I'm getting 1.4 key kWh a day right now. Since I'm just starting building...realizing research is never done. I live totally of grid in a non mobile RV. I bought crappie lead acid batteries,but a 40amp mppt.(epever) a 2000/4000 psw industrial inverter because of the heat. By 5pm my 4 101ah batts are at 14.1 at the least. Will try tonight to run fridge until it shuts down. Question. Recommendations for good batteries please. I now have about 400 a month for good ones. Thanks again. Dayrobber.

        Comment

        • NEOH
          Solar Fanatic
          • Nov 2010
          • 478

          #5
          Originally posted by Dayrobber
          Thanks guys. I'm getting 1.4 key kWh a day right now. Since I'm just starting building...realizing research is never done. I live totally of grid in a non mobile RV. I bought crappie lead acid batteries,but a 40amp mppt.(epever) a 2000/4000 psw industrial inverter because of the heat. By 5pm my 4 101ah batts are at 14.1 at the least. Will try tonight to run fridge until it shuts down. Question. Recommendations for good batteries please. I now have about 400 a month for good ones. Thanks again. Dayrobber.
          Golf Cart batteries provide many more deep-cycles vs Wal-Mart 24DC ( so-called "deep cycle" ) batteries .
          Mixing new batteries, with old batteries, is not recommended.
          Last edited by NEOH; 08-10-2019, 10:16 AM.

          Comment

          • NEOH
            Solar Fanatic
            • Nov 2010
            • 478

            #6
            Originally posted by Dayrobber
            I have 3 12v 100w panels in parallel running to 40 amp mppt to 4 12v 101ah batteries to my 2000 watt PSW Inverter. 115 degrees most of July,Southern California. My fridge/freezer at full load 600w and 6. 5 amps. Should I be wired Series or parallel at the panels?
            You only have 240 Watts ( = 80% x 3 x 100 watts ) of Solar Power and you have a 500 watt fridge, that runs very often in 115 Degree heat.
            You may need 3 more Solar Panels = total of 6.

            You need to seriously consider SERIES connected batteries = 48 Volts.
            It does make a difference and it is better long-term, since you are off-grid.
            When you add your A/C unit, you will know why.
            Last edited by NEOH; 08-10-2019, 10:26 AM.

            Comment

            • Dayrobber
              Member
              • Jul 2019
              • 40

              #7
              Thanks for Everything. I have a question. Right now for thet next couple weeks can I connect 2 12v panels in parallel for 12 volts and connect to the 3rd 12v in series for 24 volts?
              Last edited by Dayrobber; 08-11-2019, 09:40 PM.

              Comment

              • sdold
                Moderator
                • Jun 2014
                • 1430

                #8
                If you mean have one panel in series with several parallel panels, yes but it would limit the current in the whole thing to that of a single panel.

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