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ramsaymike's avatar
ramsaymike
Explorer
Mar 01, 2020

Solar charge question

Getting ready to install some solar on a 07 Concord 275. Plan is a basic DC only system with 4 x 100w panels and 2 x 6V 200ah batteries. I am a little - well maybe a lot - confused by the charging priority if there even is such a thing. Say my house base load is 100w, the batteries are fully charged and I driving down the road with 200w coming in from the panels. I assume that 100w is being 'deliverd' to the battery but from the solar system, the alternator or split somehow?
Given that I have excess solar over what is required, where does it go?
Hope this makes some sense. Thanks

16 Replies

  • You could disconnect any charging of the house batteries from the engine but the savings in gas mileage would be minimal...not worth the effort IMO. At least some charging would take place in a night drive.
  • You will not save any measurable amount of fuel going down the road by disconnecting the house battery charge circuit.
  • Right! That makes sense. My interest concerns how to maximise the use of the available solar energy. Why use the energy from the engine when free solar energy is available?
  • Generally what ever source is set to the highest voltage will get the privilege of supplying the actual power.

    Where does it go? Like when you turn off a light where does the power go? Nowhere.

    Anyway not to worry... multiple charging sources will not have any issues.
  • ramsaymike wrote:
    I assume that 100w is being 'deliverd' to the battery but from the solar system, the alternator or split somehow?
    I'm not familiar with your coach, but are you positive the alternator charges the house? Theoretically, the charging source with the higher voltage will overtake the other.

    As for where excess power 'goes', I'm not sure. My best guess is it's dissipated as heat in the controller. Another guess answer is it acts like a battery.. no draw, no power.
  • “Given that I have excess solar over what is required, where does it go?”

    Yes, you are over the benchmark one solar watt per battery amp hour. However, on overcast/cloudy days you’ll be happy with those extra two panels. Excess goes no where. The controller determines what the batteries will accept and doesn’t pass any additional juice.

    You’ll love your solar system.

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