Solar charging issues

Hi all
We have an Orion Smart setup in our camper trailer, all factory fitted.
We’ve been charging the batteries via a solar panel and didn’t have any issues until yesterday. When we plugged the solar panel in yesterday, the voltage displayed in Victron app (connecting to the Smart Solar) was only around 15V instead of the usual 19 to 20V. As a result, the battery didn’t charge and an alert popped up saying charging will only continue once the voltage is at least 5V higher than the battery voltage (i.e. around 18V).
Later in the day, after disconnected, driving (and charging via the Anderson plug on the car), everything was back to normal and the battery was charging from the solar panel in the afternoon.
This morning though, the same thing happened again. Additionally, we noticed that the voltage is fluctuating wildly between 9V and 20V at a high frequency (dropping and rising back up every 2 to 3 seconds).
Any clues what’s going on and how to fix it?


Poor connection somewhere, especially possible as you have a demountable system and always making and breaking connections, coiling wires etc. A poor connection or a break in a wire or within a panel or MC4 connector has high resistance. When no current is flowing there is no voltage drop so the controller sees 20V and starts charging. Once current starts to flow, it can not get past the poor connection, you get voltage drop, the voltage goes below 13V, the controller stops charging, the voltage recovers. This just then repeats. Get your multimeter out and use this to find the poor connection or just check the wiring and all connectors.

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