We estimate our power use between 30 and 40 amps per day (total). We have 4 Trojan 6 volt batteries with a capacity of 480 AH. We recharge with two 54 watt solar panels
. The panels
are our only source of power to recharge the batteries. Works great. Have not put alot of time on the batteries and over taxed the system.......... So all is good so far. We are sailing Maine
waters at the moment........... Not really known for super sunny conditions. At peak the panels will put out slightly over 7 amps per hour.
So with good conditions we can replace all the amps used in one day of recharge. Less than optimum conditions still allow some charging
capability and I estimate we can go for 10 to 14 days before reaching 50 percent battery
capacity. Thats two weeks with little or no sun. Chances are there will be optimum sunny conditions in much less time. In fact I would bet on it. Besides this scenario doesn't even include any attempt to ration our use.............it's figured at peak demand. I think that is the key......... To try and control the demand side of the equation.
Maybe the freezer isn't necessary.......
Perhaps the water
maker isn't really needed....
Whatever you decide you will have to match the system to the demand for sure. It's just your own personal preference.........
One last note.......research your solar panel choice carefully. Not all panels are created equal. And they are temperature sensitive. The more heat the less power. I found the manufactures performance data to be a bit misleading and somewhat confusing. Then again i am not an electrician. Found Nigel Calders work to be a good reference . IMHO this is an area (panel choice) where quality should over ride all other considerations.