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  1. #1
    Join Date
    Sep 2013
    Posts
    1

    Default Current loss in solar powered home

    I have an off the grid solar house in Baja.

    3 panels; 2 deep cycle batteries, inverter which feeds into a box for AC with two circuits coming from that, so two circuit breakers.

    2 weeks ago, we arrived to fully charged batteries. In the course of the first night the charge went WAY down. So much that they did not even fully charge in a full day of sun.

    We replaced the batteries with charged “loaners” The batteries lost all charge overnight again with only one ceiling fan running.

    Next night, same thing without even the fan running.

    The current loss is coming through circuit breaker 2. When it is switched off, there is no leak. I checked the breaker. It’s fine.

    I checked for voltage in every outlet. One outlet had a high reading in one of the plugs. I removed the outlet and capped off the wires. No change.

    My question: How do I find the leak? Once I locate it, I may have a question about how to fix it, but for now, I need to find the leak.

  2. #2
    Join Date
    Dec 2007
    Location
    Tennessee
    Posts
    1,381

    Default Re: Current loss in solar powered home

    Turn off the circuit breaker, then go to the first outlet and insert the probes of an ohmmeter in the contacts and measure the resistance. If it is not showing infinity, go to the outlet in the middle and disconnect the outlet from the circuit so that all circuits down stream. If the resistance goes up, the problem is down stream from this outlet, if the resistance is still the same, then the problem is in the first half of this circuit. Continue to divide and conquer until you find the bad circuit.

    If the resistance is infinite on the first test, then you have a capacitive loss and that is much harder to find. First, do you have any CFL's on the circuit, if so, remove any bulbs that don't work or are unusually dim or bright. The problem could be in their ballast. As far as I know, LEDs should not cause a problem. If all the CFL's look OK, then remove them all and see if you still have this loss overnight.

    Otherwise, break the circuit as I described in para 1 and reapply the current and see if the battery still goes dead overnight. Divide and conquer as I described above.

  3. #3
    Join Date
    Aug 2007
    Location
    Portland, Oregon, formerly of Chicago
    Posts
    1,583

    Default Re: Current loss in solar powered home

    Are you sure the diode in your charge controller is working? Without a functionig diode, in absence of light (nighttime), your solar cells will actually discharge your batteries. The diode acts as an electrical checkvalve, allowing electrcal flow in only one direction.

  4. #4
    Join Date
    Jan 2011
    Location
    Columbiana, Alabama
    Posts
    623

    Default Re: Current loss in solar powered home

    Quote Originally Posted by ordjen View Post
    Are you sure the diode in your charge controller is working? Without a functionig diode, in absence of light (nighttime), your solar cells will actually discharge your batteries. The diode acts as an electrical checkvalve, allowing electrcal flow in only one direction.
    True and even if the diodes are working correctly there will be some small amount of reverse flow through the diodes.

    Have you washed the top of your batteries (Keep the plugs in!) with a baking soda solution and clean water.
    Also, place the batteries on a wooden shelf.

    After a rainy spell, you might want to hook the batteries to a generator to top them off before using them. And make sure you maintain proper water levels, using distilled water.
    Good Luck from Columbiana, Alabama
    Maurice Turgeon, Hidden Content

  5. #5
    Join Date
    Jan 2008
    Posts
    1,095

    Default Re: Current loss in solar powered home

    agreed with keith3267, but if the resistance check doesn't find the problem then use the same procedure with a milliammeter placed inline temporarily after the breaker. Be sure that all bulbs are out and all appliances unplugged on the circuit as they will give a false positive reading. This will find capacitance losses as they draw power (amperage) even if the resistance of the lines reads infinity. And you may have losses in the breaker itself.

    When you are your own 'power company' you also need to plan for those times when something goes wrong, so you ought to get a generator involved to make sure that you never draw the batteries down this much again, as it will greatly shorten their life. It need not be so big that it will carry the entire system but it should be adequate to charge the batteries at their fastest recommended charge rate which will also allow for some draw while generator-charging at a normal rate. Ideally this will happen automatically, but you can hand-start at hearing a low voltage alarm which should be part of the system as well.

    Kudos for going off-the-grid and let us know what you found with the problem.

    Phil

  6. #6
    Join Date
    Jan 2011
    Location
    Columbiana, Alabama
    Posts
    623

    Default Re: Current loss in solar powered home

    All good advice but I fear that 3 solar panels are not sufficient for anything greater than a few CFL or LED lights.

    What are they rated at?
    Good Luck from Columbiana, Alabama
    Maurice Turgeon, Hidden Content

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