I currently have more solar charging capacity (260 watts max) than battery capacity in our 25' CCD with two group 24 gel cells so I plan to acquire a third larger battery for those long late fall and early spring boondocking trips. I will use a 45 amp Anderson Powerpole connector rather than switches and other wires or connectors. I already have one on my batteries to power my amateur radio equipment when I am operating under the awning or at a nearby picnic table. The connectors are polarized so you can't plug them in wrong and I keep it permenantly connected via a 12-inch cable that is curled up inside the battery box until I need it. These connectors are becoming the standard for people that provide communications support to public agencies for public service and emergencies.
You can find the Powerpole connectors from several vendors by searching the web;
http://www.andersonpower.com/product...powerpole.html is thwe manufactures web page.