jdub,
Welcome to the forum.
Let's start with the sun. This data I link to is the average number of sunlight radiation hours per year.Just look up the city closest to you and you will find the average hour of sun in your area.
www.longtermsolar.com/solar-sunlight-hours/What size marine batteries did you get and how many volts do they have?
There are few different batteries out there for different uses.
1.) Starter batteries which are used for starting a vehicle like a car or 4-wheeler. They can produce very high amps, but only for seconds because they have thin lead plates. Taking more than 15-20% of there capacity will shorten their life. Not recommended for solar.
2.) Deep cycle batteries have thicker plates and can provide deeper discharges. Up to 50% safely on a daily basis. This is why this kind of battery should be the choice for solar applications.
3.) Marine batteries are between a starter battery and deep cycle battery and will never be as good or last as long as a true deep cycle battery that golf carts are using.
There are also AGM and Gel batteries used for solar applications, but those are usually twice the money for the same capacity and will need a special charger/charge controller that can be set for this kind of battery.
A starter battery uses CA ( cranking amps ) and CCA ( cold cranking amps ).
A deep cycle battery uses ah ( amp hour )
And this is the easiest way to identify what kind of battery it is, at least in most cases.
There is no formulation that I know of that can convert CA/CCA into ah etc etc.
If you have four 100 watts 12 volt panels, that gives you about 20 amps which can charge a 200 ah battery bank. if you have more batteries than you basically need more panels.
Also a 200 ah battery can give you only 50% / 100 ah of the capacity on a daily use without destroying the battery. In a 12 volt system that would be 12 volts times 100 ah = 1200 watts.
You need to be able to charge your battery back up when the sun is out. Many locations here in the US give you around 5 hours sun per day. You have 400 watts of panels times 5 hours = 2000 watts max you can produce per day. Don't get to exited about that number because you will have losses and the panels will not give 100 watts under normal conditions. Per 100 watt panel you get about 65 watts after you figure in the losses.
What size of wires did you use?
The bigger the wire and the shorter the wire run the less resistance the wire will have and the lower the power/voltage loss will be.
If you have more than 2 panels in parallel, per code you should have fuses for every panel so when a panel short circuits it will blow the fuse and will not back-feed power to the panels which could heat the panels up and could start a fire etc etc.
Taking about fuses, have a fuse for every string of battery, charge controller and your inverter, you can use DC breakers for it. At the inverter 110 volt side, have more fuses and/or breakers.
Use DC rated hardware on the DC side of your system.
I have 500 watt of renogy panels. Each panel hooked up to a # 10 awg wire, each panel/wire hooked up to a double pole breaker so each panel can be turned off independent if needed, then it goes to a bussbar/ combiner and then to the charge controller to the batteries. I have a 2K/4K inverter that I seldom use because a inverter that is turned on and in idle without load will still use some power which is a lot for a smaller system.
Sams club has 6 volt 200 ah deep cycle golf cart batteries for about $84 each. Put 2 batteries in series and you have 12 volts 200 ah batteries for about $170. If you keep batteries cool they will last a longer time. Heat will kill them sooner.
What can you power with it?
Mostly I power 12 volt lights with it, under the cabinet lights...every day. Wood storage shed every day in the winter / heating season and rest of the year when I need light outside after dark. Sometimes my fans.
I can use the inverter and then I can power my toaster, coffee maker, and electric frying pan, fans and my air- conditioner for 1 an hour when it is dark. I must say that my batteries/system does not like to be pushed over 700 watts....it makes the battery voltage drop to much and makes the wires warm especially when I use 1500 watt items.
The real test came 1 month ago, when we lost power for 30 hours.
We ran the kitchen lights straight from the batteries and with the inverter we ran 1 light in the living room, 1 floor fan, 1 computer to watch video and made pop-corn and made 1 pot of coffee and plugged the fridge up for 1 hour and charged cell phones.