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  • Pace
    Junior Member
    • Feb 2012
    • 1

    Non profit people project O Lugar saying a huge hello

    Hi all,

    We are a non profit project based in portugal...
    We are living on 7.5 hectors of land in the portuguese mountains...




    The project here has very simple goals.

    1) To re-plant and re-condition the landscape using organic non-harmful methods of permaculture.

    2) To provide a sustainable source of healthy free food to local communities.

    3) To teach (for free) sustainable skills and methods to all those who wish to learn.

    4) To relearn, preserve and teach customs and skills of previous generations with the intent of keeping these alive for future generations.

    In November 2011 we where donated 7 hectors of land close to the city of Portalegre. The land had been unused for many years and was simply laying to waste. *In December 2011 we moved onto the land to begin the initial stages of the project.

    The project here raises no funds what so ever and relys soley on donations. *Our aim is to bring people together and create a positive change without the restrictions of the monetary system.


    We have recently been donated 5 solar panels rated at 200watt and output voltage of 36v.
    We are wondering if it it possible to charge a 12v battery from one of these solar panels even though the output charge is 36v? Would we have to stepp down the voltage to 18 volts first.. Any help gratefully appreciated...


    Peace & love


    Pace
  • Naptown
    Solar Fanatic
    • Feb 2011
    • 6880

    #2
    Yes but you will need an MPPT type charge controller which will step down the voltage without losing wattage of the panels. How many batteries are you planning and what do you intend to run from them?
    NABCEP certified Technical Sales Professional

    [URL="http://www.solarpaneltalk.com/showthread.php?5334-Solar-Off-Grid-Battery-Design"]http://www.solarpaneltalk.com/showth...Battery-Design[/URL]

    [URL]http://www.calculator.net/voltage-drop-calculator.html[/URL] (Voltage drop Calculator among others)

    [URL="http://www.gaisma.com"]www.gaisma.com[/URL]

    Comment

    • CJ SolarTown
      Junior Member
      • Jan 2012
      • 20

      #3
      You can go with a decent mid-size MPPT charge controller to get the system up and running. If you plan to upgrade in the future you may want to go with a larger size MPPT charge controller so that you are not left out in the woods with 2 charge controllers.

      MPPT charge controllers basically the bridge between the solar panel and to the battery. Keep in mind potential future upgrade and you will maximize the utility of the equipment.

      Comment

      • Mike90250
        Moderator
        • May 2009
        • 16020

        #4
        By adding a single MPPT controller, you can use 4 of the panels right away.
        Wire 2 in series, and another 2 in series, to get 2 strings of 72V panels @ 800W
        Parallel the 2 pairs of strings into a 60 amp MPPT controller, and you will be able to deliver
        60 amps to a 12V battery bank, or
        30 amps into 24V battery or
        15 amps into a 48V battery.

        There are several GOOD MPPT controllers that can do this:
        Midnight Solar Charge Controllers

        Outback

        Morningstar

        Xantrex/Schneider

        Other mfg's are "unknowns" you can find cheap ones on fleabay, but their performance is often questionable.

        The inverter guidelines are :
        up to 1,000 w of load, 12V battery
        2,000w of load 24V battery
        over 2,000 w you need a 48V battery. These guidelines are dictated by the amount of current flowing in the DC circuit, and the losses involved. 1,000w @ 12V = 80 amps

        ASK more questions before you buy anything.
        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

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