I have an installation where three MPPT's are installed. One of the MPPT's, the 250/100 continues to have a voltage, which is about the same as the battery voltage, on the incoming side of the controller even when the solar panels are disconnected from the controller. The other two MPPT's don't have this, or at least a very low voltage. The controller looks like it is functioning properly.
My question is : is there a problem upcoming, or is this normal behavior ?