Electrical

Modern gear such as refrigeration, chartplotters, radar and computers required a well sized and maintained 12v system.

Batteries

Benefits of 6v golf cart batteries
Detailed discussion of battery types by Jim Moe
Battery monitor placement

Alternators and Battery Chargers

All about alternator belt tension & pulleys
Alternator mount/bracket upgrade Important safety upgrade for M25 (not XP) owners
Battery charger discussion & Xantrex product evaluation by John Nixon
In-depth considerations on the Xantrex XC3012 battery charger and installation
Truecharge battery charger installation under the sink on a Mk II

Electrical Panel, Wiring & Lighting

Adding AC panel lights for readability at a distance
Cabin lights -troubleshooting
Electrical panel: Designing and building a new one by Mike Vaccaro
Electrical system upgrade: A comprehensive electrical system upgrade by Jim Moe
Electrical system upgrade by John Gardner
Electrical system upgrade: Another perspective by Mark Elkin
Electrical system upgrade by Capt. Al
Engine electrical harness Important WARNING for M25 owners
Galley light installation
Galley light mounts
Glow plug solenoid Installation for faster starting
Nav Lights Troubleshooting
Panel switch telltales: How to tell the on/off state of panel switches from a distance
Unswitched 12V wiring instructions

Generators

Wind generator POV

Inverters

Freedom 20 installation

Starters

Secondary start switch
Slow start fix with a wiring upgrade, starter re-build, and new starting battery by Mike Vaccaro

Items of Interest

Lightning

There are over 75 Technotes on these subjects.