Contoller dead?

Discussion in 'Solar Power' started by stegla, Aug 22, 2016.

  1. stegla

    stegla Read Only Funster

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    Hello all,

    We've had our MH for about 8 months and in all that time I think that the solar panel has never charged the batteries.

    The MH has a PV Logic solar panel kit fitted of about 100W? 2 x 95Ah leisure batteries. The controller is a STCC 10 Solar.

    The Solar panel itself seems to work with a 21V output.

    Question1........... If I have to replace the controller, is it worth upgrading to a better one?

    Question2........... The MH has a 12V compressor fridge and blown-air heating. Should we have adequate electrical power for a weekend off the grid, with a little help from the sun?

    Steve
     
  2. John Laidler

    John Laidler Funster

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    Q2 is an easy one I think, yes, assuming your leisure batteries are in good health. :)

    But before you consider replacing the controller I suggest confirm it is faulty first. Our controller stopped working earlier this year but it was only a blown fuse.

    Can you measure or read the battery voltage? When the sun is shining you should expect something like 13.6 or 13.8 volts assuming the vehicle has been sitting quietly for a few hours with no major loads running. If you do see this voltage then the controller is probably working.

    Some controllers are dual 12 or 24 volts and these must be connected to the leisure batteries first so the controller knows what voltage to produce.
     
  3. hilldweller

    hilldweller Funster Life Member

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    This came up the other day, someone was saying their solar voltage was 14/21 alternating and I said "normal as the controller keeps boosting the battery". If yours is steady 21V then I'd worry about the controller.

    What I would do..... Unscrew one solar wire ( or pull a fuse if you have one ). Remove one battery/solar wire and put a 10A meter in line, reconnect solar and see what current flows into the battery. Simple as that.
     
  4. stegla

    stegla Read Only Funster

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    Hi DBK, the battery voltage at the controller is 12.65V.

    I'll try disconnecting and reconnecting the controller in the correct sequence to see if this helps?

    Steve
     
  5. John Laidler

    John Laidler Funster

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    12.6 volts is about the normal voltage for a battery when it has settled down after charging. If the sun was shining at the time then I think you are right to think the unit is probably goosed. If you can see 21 volts at the terminals from the PV panel and it isn't charging then I think that confirms it.

    I've fitted a Victron 75/15 controller to mine and this is a very well reviewed unit but you will find others recommend different suppliers. What you want is an MPPT type controller and it should cost around £70, much less and it is unlikely to be a proper MPPT one.
     
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  6. stegla

    stegla Read Only Funster

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    Brian, I saw only 16mA draw from the solar panel!

    DBK, £70 is about what I had in mind.

    Steve
     
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