LED 12 volt boat wiring mystery

Discussion in 'The Projects Forum' started by JAT, Jun 10, 2014.

  1. JAT

    Thread Starter New Member

    Jun 10, 2014
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    I'm trying to wire three LED lights -- two navigation lights and an interior light -- to a 12-volt source. As you'll see, I have no idea what I'm doing wrong.

    My 12-volt source is a lead-acid motorcycle-sized battery. Incidentally, it's fed by a solar panel via a controller, which seems to work well; the battery continues to output 12 volts at least.

    The load is connected to the load terminals on the controller. While this is new to me, I believe it works correctly because it seems to output 12 volts.

    The LED light leads are connected this way : one lead to a positive bus strip, the other lead to one blade of a two-blade (on/off) toggle switch. The second blade of the toggle is connected to the the negative bus strip. I have three of these, and I expect to be able to operate the lights individually. So far, this all seems obvious to me, but maybe you have spotted my mistake.

    Here's the behavior I get. If I turn on only one of the three switches, I get the single, correct light to illuminate. Once I turn on a second, none of them one illuminates. It doesn't seem to matter which one I start with.

    Clues. I believe two of the LED bulbs are polarity-correcting, while the third probably is not.

    What am I doing wrong? Should I suspect/blame the solar controller and wire the load directly to the battery? Should I be switching the polarity of the LEDs in some logical way to "align" them all? Should I not expect three LEDs with possible variations in power consumption to run on the same circuit?

    Running without nav lights is illegal and dangerous, as you could guess. I'm stuck -- and yet it seems so simple.

    Thanks for any illumination you might offer.

    jat
     
  2. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,394
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    I would like to see a picture of how things are connected.
     
  3. #12

    Expert

    Nov 30, 2010
    16,320
    6,818
    This seems contradictory: The battery is charged by a solar panel with controller, and it works, but you want to know if you should connect to the battery instead of the solar panel.

    I think the answer is, "yes" but I can't figure out why the output of the solar panel controller and the battery are not the same place.

    Then there is the consideration that raw LEDs need a current limiting resistor and 12 volt LEDs usually have the resistor provided. Which do you have?
     
  4. JAT

    Thread Starter New Member

    Jun 10, 2014
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    The solar panel controller is a separate appliance from the solar panel itself. It's this one :

    http://www.steca.com/index.php?Solsum-F--6-6F--8-8F--10-10F537c98ece9b31


    It has three sets of terminals : panel input, battery, and load. Its docs say that you can connect the load to the controller and that it will limit load to protect a low battery. This has the disadvantage that it may turn off some critical item, so you can also forego the battery protection and connect the critical item directly to the battery I have not done this. I wish I knew whether the controller is turning off two of the LEDs and why, but, since the voltage is OK, I don't think it is.

    (I noticed they have changed their webpage and there is more information about the controller. Maybe this is a clue "Reverse polarity protection of module (≤36 V),load and battery".)

    I'll try connecting directly to the battery instead of to the controller, but I suspect the problem has more to do with the condition of the LEDs rather than the power supply.

    The LEDs are these two nav lights:

    http://marineledshop.com/festoon-le...r-lights-43mm-1-4-watt-warm-white?path=115_82

    http://marineledshop.com/festoon-le...-4-led-bulb-31mm-0-7w-warm-white?path=126_127

    and a cheap dome light that just seems to work.

    I think the resistor is built in to the nav lights. When they do work (one at a time) they are not sensitive to polarity orientation in the fixture, so I guess that is also built in. The dome light is sensitive to polarity.
     
  5. JAT

    Thread Starter New Member

    Jun 10, 2014
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    I hope my crude diagram makes sense. (You can see I'm in unfamiliar territory with this stuff.)

    Image attached.
     
  6. #12

    Expert

    Nov 30, 2010
    16,320
    6,818
    Your drawing looks correct. I think the controller is messing with you. Measure the battery for about 12.5 volts, not 12.0 volts. A full battery is more like 12.6 V. A dead battery is 12.0V

    If the battery is good, and full, try connecting to the battery.
     
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