I have 3 100w (5 amps each) solar panels in parallel on my boat and have enjoyed 12 or 13 amps but this year I struggle to see 4 amps. I just checked the voltage. With the panels disconnected I see 20.4v in full sun. However when connected to the controller is see around 15 or 16v at the controller. Disconnect the solar wires at the controller and the solar output is back to 20v.
The only thing that has changed is one of the panel was damaged and replaced with one of the same spec.
All advice appreciated.
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