Connect Solar Panels in Series or Parallel?

[gandalf]

While investigating the wiring on the 12V system on my recently acquired boat I discovered that the two solar panels were connected in series, the current then passing through a regulator and directly into the house bank of batteries. Is this normal or desirable? I had assumed the panels would be wired in parallel with the regulated current being directed to the Cole-Hersee selector switch, so that you had the option of charging either the cranking battery or the house bank.

My experience is very limited here and I would welcome any advice.

Cheers,
Frank

[Captain Bill]

If you have an MPPT controller this arrangement would be acceptible. If you start the engine every once in a while the starting battery is not likely to need charging by the solar panels. I have my batteries connected through a combiner switch so the starting bank is charged any time there is sufficient charge on the house bank.

[scotte]

If the charger is the MPPT type, then this is a very normal way to do it. An MPPT controller doesn't really care what the input voltage is, it will convert the input to whatever is needed for the batteries. A series connection has some negative points (like shading one panel can affect both), but high voltage at less current also means less voltage loss in the wire.