Have any of you read Managing 12 Volts: How to Upgrade, Operate, and Troubleshoot 12 Volt Electrical Systems (Paperback) by Harold Barre
It is a great book. The information in this book is a basic but thorough education in the total management of a 12V system in a car, boat or RV. It is a comprehensive reference that contains clear tables, diagrams and illustrations, showing you how to use and maintain a 12V system.
I found it in the public library. But it is a must buy if you really want to know the fundamentals. The more you read it the better you will understand all aspects of a 12 V system. This book will teach you how batteries, alternators, chargers, switches, sensor, actuators, solenoids, and electrical circuits actually work. With the information in this book you can make intelligent decisions when selecting or operating a system.
It helped me when I built the electrical system for my Zephyr Teardrop.
http://www.nfdc.net/home/cbdb/Teardrop%20Electric.htm
The other information I found most helpful was from 12 Volt Side of Life and Battery Information
http://www.ccis.com/home/mnemeth/12volt/12volt.htm
And from the Poop Sheet on Batteries by Phred Tinseth
http://www.phrannie.org/battery.html
Dee Bee