Solar volts

Discussion in 'Motorhome Chat' started by Glynn, Feb 5, 2012.

  1. Glynn

    Glynn Read Only Funster

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    If your measuring the output of 2 solar panels say 4x2 ft in dim daylight conditions like today, how many volts would you say a meter would read ?.
     
  2. pappajohn

    pappajohn Funster Life Member

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    depends if you got snow on the roof :RollEyes:

    been checking my batteries today, engine battery down to 11.5v :Eeek:

    stuck a clamp meter on the panel to hab battery lead and getting no amps but then remembered the panel is covered by 2" of snow. :Doh:

    hab batteries well charged and charger putting in 850ma
     
  3. Glynn

    Glynn Read Only Funster

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    Thanks John but it was volts I was interest in. Took a reading this aft and the panels were giving a reading of under 4 volts.
     
  4. pappajohn

    pappajohn Funster Life Member

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    you should only get such a low reading if the batteries aren't connected to the solar controller(blown fuse etc) and the panel is covered by snow, or it aint working and the batteries are completely dead.
    the volts shown will be the voltage at the battery....not the amount of charge going in.

    how did you check the voltage ?

    well charged battery should be around 12.7v...anything higher and the panel is working but you cant tell how well.
     
  5. Glynn

    Glynn Read Only Funster

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    All I did was remove the fuse from the solar controller and then probe the controller output terminals
     
  6. pappajohn

    pappajohn Funster Life Member

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    sounds like snow on the roof then :Laughing:

    open circuit in reasonable sun should be around 17v from the panels to controller.

    controller to battery will depend on battery voltage but with the fuse pulled it should show battery voltage depending where the fuse is....panel side or battery side of contoller.
     
  7. otis the staffy

    otis the staffy Read Only Funster

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    solar volt

    Slightly off track but having had solar panels on van roof for several years Iam looking to put 4kws on home roof has anyone had them fitted.:thumb:Stay Safe
     
  8. pappajohn

    pappajohn Funster Life Member

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    i'm having a bit of trouble expressing myself today :Doh::Sad:

    if the fuse is between controller and battery (where it should be) and is pulled out you will read the panel output in volts at the output terminals...around 17v

    because you have snow on the panel it isnt working to its full capacity which is why you only read 4v.

    with the fuse in place you will be reading the battery voltage as it will be higher than the (snow covered) panel output voltage.

    hope that makes more sense :Doh:
     
  9. pappajohn

    pappajohn Funster Life Member

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    sorry, cant help with that at the moment, but we, company i work for, are looking into installing them as part of our business venture.

    i'm sure we'll learn more about them in time.
     
  10. Glynn

    Glynn Read Only Funster

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    The fuse is fitted between the panels and the controller.
    I took out the fuse and tested the outputs that come from the roof, must admit though I was struggling holding both the meter and probesso maybe ( hopefully ) I missed seeing the 1 which could have been the first digit, so maybe it was reading 13.8 & not 3.8:RollEyes:.

    We have no snow.

    The battery green indicator was on ( in range ) and the charge green light was also on. So it appears it's working.
     
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