Book excerpt: The 12-Volt Bible for Boats is a clear, nonthreatening introduction to the 12-volt electrical systems used on small boats to power everything from reading lights to bilge pumps. This second edition is thoroughly updated with respect to modern batteries, breaker and panel design, alternative energy sources, and troubleshooting equipment, but it retains the fundamental simplicity that is the source of its enduring popularity (more than 100,000 copies sold).