wiring solar panels

Discussion in 'The Projects Forum' started by dorothy, Dec 15, 2012.

  1. dorothy

    Thread Starter New Member

    Dec 15, 2012
    3
    0
    Hi

    I understand the difference between parallel and series, ie one increasing voltage and the other increasing ampage.

    I need to wire 12 x 12 volt solar panels to install a 24 volt system. Because of the space I have to put the panels in a straight line. I have looked at quite a few sites discussing this but still can't get my head round it. All the diagrams seem to show the panels in side by side pairs.

    I have wired positive from first panel to positive on third then 5th then 7th panel etc., and negative from second panel then to negative on 4th, 6th, 8th panel etc. I know I have to wire across from negative to postitive to increase 12 volts to 24 volts. What I am not sure about is if this only has to be done once to increase from 12 to 24 volts. If I repeat along the panels will it keep increasing the voltage. Either my ampmeter is going crazy or or I am over egging the system, as the meter was reading 126 volts.

    Can anyone help with a diagram (idiots guide).

    thanks
     
  2. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    Wiring the panels in series will give you a higher voltage. Wiring them in parallel with give a higher current output.

    Depending on your panels, you may need to wire pairs in series then wire all of those pairs in parallel,
     
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  3. wayneh

    Expert

    Sep 9, 2010
    12,126
    3,048
    Put 6 in parallel (12V) and put this in series with another group of 6, to get 24V.

    This assumes all the cells are nearly the same. It also assumes that a 24V nominal, open-circuit voltage is really what you need. If you're trying to charge a 24V battery, you'll likely have to put all the cells in series.
     
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  4. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    I think I get where you are stuck. Each pair is in series, then the pairs go in parallel,like so:

    [​IMG]

    As you wire this, each pair should read 24V, and that should stay 24V as each pair go in parallel.
     
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  5. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    1,012

    How did you determine it is 6 in series form the OP? The OP never really mention the voltage of the panels. Assuming 2 standard 17V panels, two in series would be needed not 6. So 2 in series with 6 pairs in parallel.
     
  6. dorothy

    Thread Starter New Member

    Dec 15, 2012
    3
    0
    Hi

    Thanks for all the replies and especially the diagram. It was very cloudy and nearly dark by the time I finished wiring the panels today but I will check them tomorrow. It looks like I have wired them as per the diagram. The voltage reading still a bit of a puzzle.
     
  7. #12

    Expert

    Nov 30, 2010
    16,298
    6,809
    That's normal. Solar panels always give strange voltage readings at, "nearly dark".
    Try again tomorrow.
     
  8. wayneh

    Expert

    Sep 9, 2010
    12,126
    3,048
    I thought the "12 x 12V" meant 12 individual cells at 12V nominal output each. If that's not right, the OP can ignore my previous comment.
     
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