Solar, House, Starter, Troller - Worried about charging..

[PSteward]

Hello!

I thought I had my battery situation figured out and took my two older deep cycle and created the house set and purchased a dedicated starter battery better sized to my engine size (7.4L V8), I was planning to combine (manual combiner) the batteries once the engine is on to help top up the house but am worried that the starter (which will already be mostly charged) will get over charged. Is that true?
After I understand that I am looking to integrate solar direct to house, and how to interface a trolling battery into the mix so it can get topped up when on the go or on solar, in addition my engine starter and alternator connection is not separate at the moment (one wire to my starter only).
I had started going over planning earlier but now I finally have access to the boat so now the picture is getting clearer in addition to getting more additions.

Thanks,

--Phil