Over Voltage?

Discussion in 'Solar Power' started by Jackomet, Aug 1, 2009.

  1. Jackomet

    Jackomet Read Only Funster

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    Hi,
    Newbie to SP stuff here
    I have just bought 4 x 15w SP (Maplin £199) array to help charge my Motorhome batteries.
    They are rated 3.42A @ 17.5V individually. Connected in // to a controller that has various outputs both physically & volt wise down from 12v.
    Here's the prob; measuring unloaded each panel is 20v-22v in the shade & 22v-27v in direct sunlight. So when connected to controller it just does not switch on, over voltage I guess. Connect controller to a battery or battery charger etc. as input and switches on OK.
    Connect all in // to a load and I'm getting 27v @ 4A i.e. 108 W. Is this magic?
    What's going on? BTW not getting any ideas from manufacturer or dealer. Checked my voltmeter & OK.
    Any ideas?
    Regards
    JK
     
  2. hilldweller

    hilldweller Funster Life Member

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    Sounds like you're drunk :)

    Yet you've done all the logical tests.

    What maplin par number - can't find anything from your description.

    >> Connect all in // to a load and I'm getting 27v @ 4A i.e. 108 W. Is this magic?

    Nah, you're drunk. Or standing next to a TV transmitter.
     
  3. bobandjanie

    bobandjanie Funster Life Member

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  4. hilldweller

    hilldweller Funster Life Member

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    Ah, that big lump. I thought they had those much cheaper a while ago, still too big and heavy.

    The "obvious" conclusion is his 4A load isn't. I've a 5W panel next to me and off load on a dull day it's showing 20V. So that ties in with his figures. But not on load figures.

    I wonder if the controller is faulty or it shuts down because there is no load when the panels are connected ?????
     
  5. Wildman

    Wildman Read Only Funster

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    I suggest its not 4 amp but. 400 milliamps i.e. .4 amp. to get 4amp from 60W panels is impossible. you would be lucky to get a quarter of that at midday on midsummers day in full sunshine with panels angled at the sun.
     
  6. Douglas

    Douglas Read Only Funster

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    I think wildmans right, also do the panels come ready wired or do you have wire them together, the reason I ask is; is it possible that there is a panel thats in series and not parallel?

    Doug...
     
  7. pappajohn

    pappajohn Funster Life Member

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    do maplins make their answers up as they go along.

    i looked at these and checked the questions and answers page.

    it specificaly said.....not suitable for permenant outdoor mounting and not waterproof.

    not any more,

    Q- could the panels be Permanently mounted outside - ben
    Answer- Yes the panel is weatherproof.

    BTW.....PEAK OUTPUT is rated at 3.85amps (unattainable anyway) so how yours is reading 4amps is a mystery but it sounds like a faulty controller.
    it should read around 17v at the panel (input) side of the controller and around 13.6v at the battery (output) side of the controller with a well charged battery.
     
  8. johnsandywhite

    johnsandywhite Read Only Funster

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    :Smile:Not necessarily so. The average reading of an average Solar Panel should be 17.8 volts. However. The 80W Solar panel I have just fitted to my Suntor was reading 20.8 volts before I connected everything up. Today in the rain and cloudy it was reading 13.6 on the Solar panel side and 13.5 on the battery side. :thumb:
     
  9. pappajohn

    pappajohn Funster Life Member

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    agreed john but i refered to 'average' readings...:Blush:

    and when you read any 'blurb' on panels it nearly always states (X) amps @ 17.? volts
     
    Last edited: Aug 1, 2009
  10. Jackomet

    Jackomet Read Only Funster

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    Maplins 60w SPs

    Other people who are not me,
    Got an EM from Maplins and it turns out that some of the wiring is reversed on some of the leads, which they say they will replace. After figuring out what was what i.e. connecting red to black etc. finally get a reading of 17.7 v at controller and 3.1 a on load on a shiny day. Don't know how I was getting the previous numbers tho.
    JK
     
  11. hilldweller

    hilldweller Funster Life Member

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    Give this man a lollipop - the only one who gave the right answer !
     
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