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islandvagabonds's avatar
Feb 20, 2016

Morningstar 30amp solar charger display

The digital display on my Morningstar PWM 30amp solar charger shows battery volts and amps. When the display reads 7amps is that telling me what the panels are producing or is it the amps that the batteries are accepting?

thanks in advance for the help.
  • pianotuna wrote:
    It is fairly easy to test this. In good solar conditions, turn on a large load. If the display shows a larger number--then you know it is set to measure what is leaving the charge controller, and not what is coming in.


    sorry PT
    yes the load might show an increase, but
    the controller ALL ways shows what is being produced and sent to the system
    NOT what might be available,
    think about the electric meter on the side of the house
    it shows what you are using
    NOT the MEGA WATTS available on the utility power line

    if the batteries and house circuits only take 7amps, them that is all that is being produced, not 30amps , that extra difference is
    "Potential Power" not being produced or utilized
    if it was being produced and not used the controller would be dissipating it as heat...OUCH
    it is voltage VRS battery circuit resistance , which limits the flow to 7 amps, even if more is available

    if you turn on a load and it goes up then more is available
    if the flow does Not increase, like late afternoon or early morning, then that is all the solar energy available

    but always the meter shows BOTH... what is going to the system, IS what is being produced
  • It should be the controller output amps. Those amps supply both house loads and then battery charging. So you might have 3A for house loads and 4A for battery charging.
  • It is fairly easy to test this. In good solar conditions, turn on a large load. If the display shows a larger number--then you know it is set to measure what is leaving the charge controller, and not what is coming in.
  • Both
    It is what is going into the batteries
    You might have 50 amps solar capacity under ideal conditions
    But if if the batteries don't need it then they are not going to take it
    Also early in the morning the batteries will be hungry, but the panels won't have enough sun to produce full power
    So all they can produce is a few amps

    So yes the panels are producing 7 amps not more , only 7 because
    That is either all they can produce at that moment or because that is all the batteries will accept
    That IS the amount being produced and sent to the batteries
  • My solar controller shows what is being sent to the battery bank.

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