Using DC-Solar SCT20 Trailer based system for cabin.

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • RMPowell01
    Junior Member
    • Feb 2021
    • 4

    Using DC-Solar SCT20 Trailer based system for cabin.

    First I know very little about building a solar system. I understand basic DC voltage and wiring as well as basic AC voltage and wiring. I have rewired a restored old car and wired two homes I built.

    I want an off grid system that will provide minimum 6kw daily in the winter and about 13kw in the summer. My worst case sun hours is December at about 2.42 based upon my cabins to be zip code.

    My plan is to purchase 2 of these DC-Solar trailers and merge into one system. I just came home with the trailers, one with the Kubota GL11kg generator. All batteries on both systems were dead. They were not dry. I have sun today so I have placed both units on a manual EQ charge to see what happens. I do not want to replace the batteries but will do so if necessary.
    Other than running the manual EQ is there any other steps I can take that may give me usable battery pack for any length of time? The units have Midnite solar classic 250 charge controller.
    How many time should I run the manual EQ before I give up on the battery pack?
    If I do have to replace the batteries, has anyone had any experience with rebuilt batteries?

    I will be taking the contents of the trailers off and mounting them to the ground. Most likely the mount will be to a concrete pad. The solar panels will be in a meadow that has no sun blocking until about 3 hours before sunset when tree shade will be a problem. If I place the units further away from the cabin (200') I can keep the PV panels in the sun until about 1.5 hours before sunset. The problem is I am in a valley with the hill to the immediate west of the cabin. How much value is the late afternoon sun when the panels are fixed positions E-W.
    Should I move the solar system into the middle of meadow?

    I wanted the generator to provide power to charge the system batteries or power the cabin when the sun does not provide the power needed. I expect this to happen in the winter.
    Should I just use the generator to power the cabin or is best to power the battery bank?

    I desire to combined these two systems in to one larger system.

    Is anyone willing to assist me on this project? I have questions like the Sunny Island 6048 controls say they can each handle up to 100kW but these trailers come with 2 for a 10kW system. Why? The combined PV is only 48kW before solar panel degrading.why

    Does anyone know where I can obtain a system wiring diagram?


  • bcroe
    Solar Fanatic
    • Jan 2012
    • 5198

    #2
    Originally posted by RMPowell01
    First I know very little about building a solar system. I understand basic DC voltage and wiring as well as basic AC voltage and wiring. I have rewired a restored old car and wired two homes I built.

    I want an off grid system that will provide minimum 6kw daily in the winter and about 13kw in the summer. My worst case sun hours is December at about 2.42 based upon my cabins to be zip code.

    My plan is to purchase 2 of these DC-Solar trailers and merge into one system. I just came home with the trailers, one with the Kubota GL11kg generator. All batteries on both systems were dead. They were not dry. I have sun today so I have placed both units on a manual EQ charge to see what happens. I do not want to replace the batteries but will do so if necessary.
    Other than running the manual EQ is there any other steps I can take that may give me usable battery pack for any length of time? The units have Midnite solar classic 250 charge controller.
    How many time should I run the manual EQ before I give up on the battery pack?
    If I do have to replace the batteries, has anyone had any experience with rebuilt batteries?

    I will be taking the contents of the trailers off and mounting them to the ground. Most likely the mount will be to a concrete pad. The solar panels will be in a meadow that has no sun blocking until about 3 hours before sunset when tree shade will be a problem. If I place the units further away from the cabin (200') I can keep the PV panels in the sun until about 1.5 hours before sunset. The problem is I am in a valley with the hill to the immediate west of the cabin. How much value is the late afternoon sun when the panels are fixed positions E-W.
    Should I move the solar system into the middle of meadow?

    I wanted the generator to provide power to charge the system batteries or power the cabin when the sun does not provide the power needed. I expect this to happen in the winter.
    Should I just use the generator to power the cabin or is best to power the battery bank?

    I desire to combined these two systems in to one larger system.

    Is anyone willing to assist me on this project? I have questions like the Sunny Island 6048 controls say they can each handle up to 100kW but these trailers come with 2 for a 10kW system. Why? The combined PV is only 48kW before solar panel degrading.
    To understand and discuss the problems, first understand the units involved. Energy
    is measured in KWHours, like 6 KWH or 13 KWH per day. KW is a measure of energy
    flow, or power. It is difficult to build an efficient, remote battery system, because of the
    wiring losses conducting lower voltages at higher currents.

    How do you combine 2 @ 100KW systems to get a 10KW system?
    Its hard to believe a 48KW solar array could be mounted on manageable size trailers.
    Bruce Roe

    Comment

    • organic farmer
      Solar Fanatic
      • Dec 2013
      • 644

      #3
      Originally posted by RMPowell01
      ...
      All batteries on both systems were dead. They were not dry. I have sun today so I have placed both units on a manual EQ charge to see what happens. I do not want to replace the batteries but will do so if necessary.
      Other than running the manual EQ is there any other steps I can take that may give me usable battery pack for any length of time?
      An EQ charge should boil the water in the cells. You need to closely monitor the levels of every cell during any EQ charge.



      ... How many time should I run the manual EQ before I give up on the battery pack?
      Keep the EQ charge going until the specific gravity of every cell has peaked.



      ... I wanted the generator to provide power to charge the system batteries or power the cabin when the sun does not provide the power needed. I expect this to happen in the winter.
      Should I just use the generator to power the cabin or is best to power the battery bank?
      Either way, you will still be doing your EQ charges using the generator.

      4400w, Midnite Classic 150 charge-controller.

      Comment

      • RMPowell01
        Junior Member
        • Feb 2021
        • 4

        #4
        Bcroe,

        Hope I am doing this right. I am looking for 6kw total usage per day in the winter and 13kW used per day in the summer. This is not an hourly total. I am not saying combine two 100watt systems. Each system has 10 240/250 watt panels. Using both systems is 20 panels or 20 times 240. 4800 watts per solar hour in a perfect world. It should say 4.8kW not 48kW. The original DC-solar literature says this is a 10kW continuous 22kW surge system.

        Comment

        • RMPowell01
          Junior Member
          • Feb 2021
          • 4

          #5
          Organic Farmer

          I am going out to check the specific gravity of the cells shortly to see what has happened. It was about 36 degrees when I put these units on manual EQ. The EQ was done using the Panels. I have not yet learned how to start this generator when the batteries are dead.

          Roger

          Comment

          • Mike90250
            Moderator
            • May 2009
            • 16020

            #6
            Generally, a lead acid is ruined if it sits discharged for more than 72 hours. If yours sat for weeks, it's not really worth trying to salvage them. Buy new ones and used the old for the core refund.

            An EQ charge can warm the batteries, but it does not boil them. It causes hydrogen and oxygen bubbles to form, which gives the appearance of boiling maybe, but if the batteries heat up much past 100F, charging should stop till they cool down. Warm batteries have a very short life

            Before a intensive charging cycle, make sure electrolyte is above the top of the plates. As batteries charge, the electrolyte warms ands expands a bit. If filled to the full mark, acid will bubble out and make a real mess. Top off the cells when they are warm right after a recharge or EQ
            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

            Comment

            • bcroe
              Solar Fanatic
              • Jan 2012
              • 5198

              #7
              Originally posted by RMPowell01
              Bcroe,

              Hope I am doing this right. I am looking for 6kw total usage per day in the winter and 13kW used per day in the summer. This is not an hourly total. I am not saying combine two 100watt systems. Each system has 10 240/250 watt panels. Using both systems is 20 panels or 20 times 240. 4800 watts per solar hour in a perfect world. It should say 4.8kW not 48kW. The original DC-solar literature says this is a 10kW continuous 22kW surge system.
              Getting closer. Your daily consumption is measured in KWHours, not KW.
              10KW continuous and 22KW surge sounds like the rating of the generator.
              Bruce Roe

              Comment

              • RMPowell01
                Junior Member
                • Feb 2021
                • 4

                #8
                That is correct. Right now it look like I need new batteries as the EQ using the solar panels did no give me any reading in the battery cells. I think I did it right, I set the midnite solar controller charge manual EQ and i had the SMA inverters off. The reading on the Midnite controller had Votls in and Battery Volts but at the end of the day there was no specific gravity reading in any battery cell.

                Comment

                Working...