G'day Gary and Lee,
Before you can successfully scope some sort of battery and charging system you do really need to measure your 12vDC consumption with your rig at home.
This will then permit you to size your battery and then charging needs.
As a general rule of thumb, you never draw more than 50% of your amp hour capacity from a battery between cycles in order to give a reasonable life expectancy.
I use these little Watt Meters and find them very helpful to measure how many amp hours I consume. They measure a number of 12volt parameters, the most useful being the accumulated Amp Hours consumed.
Eg
http://www.beachloversleds.com.au/sh...current-meter/
Or
http://www.aussiebatteries.com.au/?rf=kw&kw=Watt+meter
There are variants of these type of meters as with prices.
Once you know your consumption, you are well on the way to being able to size solar charging systems and with them, the considerable variants that need consideration.
Steve