Proper output of my PV panels

Discussion in 'Start here' started by C.C., Jul 4, 2017.

  1. How do I know if I am getting full output from my panels? I have four 100-watts panels connected in
    parallel to a P30 charge controller and separately two other 100-watts connected to another P30. The amount of current generated by the 4 panels and the two panels are very similar as indicated by the charge controller. Shouldn't I be getting double the amount on the 4 panels?
  2. Tuicemen

    Tuicemen Solar Guru

    I'm Unfamiliar with the P30 however there are some factors which will affect amps reflected in a controller.

    Location of panels ( are they all at the same angle and getting full sun when checking)
    Time of Day ( your controller will be working hardest early in the morning when batteries are lower, this is when you should be comparing)
    Make and year produced (amps/volts can vary from manufacture to manufacture as well newer modules will usually have higher volts/amps)

    Are you comparing with both controllers connected to the batteries?
    Since a controller reads the state of the batteries and restricts voltage/amps based on the state to prevent over charging it will see the amps/volts of the other charger as well if it is connected at the same time.
    With both controllers in use one will usually cause a performance restriction of the other.

    Have you tested each panels amps/volts output separately with meter to be sure they are putting out what is stated?

    I have 3 controllers (all different) in use, none read what is expected if all connected at the same time.
    Changing charge set points so one is slightly higher can improve performance (not sure if this is possible with the P30)
  3. WindyFAQ

    WindyFAQ WindyNation FAQ Staff Member

    The controller will limit the amount of current sent to the battery based on the battery State of Charge (SOC). Make sure both controllers are connected to the same two battery posts, which, if there are multiple batteries, should be the positive post of one battery and the negative post of another battery (preferably at opposite ends of the bank)

    If there are still doubts of a panel's performance, you can disconnect the panel from the extension cable and/or controller and measure the panels Voc (Open Circuit Voltage) and Isc (Short Circuit Current) as described in the following guide: Testing%20a%20Solar%20System_ R1.pdf

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