Batteries: Batteries should be load tested before replacing in your boat. Batteries
more than about three years old probably should be replaced. Many don't even last that
long. Boat batteries usually experience just about all of the things that kill batteries
quick such as deep discharging, sitting around in a semi-discharged state, pounding and
vibration, then overcharging when the thing finally won't start at all and the owner puts
the charger on it and then proceeds to leave it on too long. This is why marine batteries
usually do not last very long compared to car batteries which are usually used daily,
never deeply discharged, and almost never connected to a charger for long periods of time
and overcharged. The use of a quality, marine rated, battery charger can add to your
battery life. Use an automotive type charger only for temporary use on a small boat while
you are present. Larger boats should have permanently installed marine grade chargers for
Terminals and connections should be inspected and replaced if they show any signs of corrosion. Anti-corrosion spray should be applied to all battery terminals and electrical connections subject to corrosion. All electrical items should be checked to be sure the correct fuse is installed either in the fuse panel or at the battery if the accessory is wired directly to the battery. This is extremely important, as many people have improperly installed equipment on their boats. Wires must also be sized for the current used and to keep within allowable voltage drop. Consult a marine professional if you are in doubt about any of these items.
Test all electrical items and make sure safety items such as automatic bilge pump, bilge blower, running lights are present and operational.
If you have 120 volt or more shore power aboard, make sure your shore cords are in good condition and are at least rated 30 amp marine grade. Your power should be controlled by a marine rated circuit breaker panel featuring reverse polarity protection and convenience outlets should be protected by ground fault circuit interrupters. All boat wiring must be made in marine grade "boat cable" which is stranded and tinned cable with an outer sheath identifying it as such. If you have doubt as to the condition of any of your wiring, consult a marine professional. Most boats built in the last 15 or so years comply to most of these standards. The worst troubles we find are again, owner installed equipment. Wiring such as lamp cord and other inadequate materials turn up frequently in our inspections of customer's boats.
Never leave portable electric heaters running unattended. Spring and fall are
unfortunately the time that most boat fires occur, usually due to electric heaters. They
are not rated or approved for continuous use, so pull the plug when you leave. Most boat
fires, especially at the dock are electrical in nature and are usually due to overloading
of circuits or using substandard heating appliances. Be careful of this. If you want to
live on your boat, install safe built in heating units that are rated for continuous duty,
equipped with over temperature limit switches, and make sure your service can handle it.
You will need at least dual 30 amp service to handle any type of heating safely, and a 50
amp 240 volt service for the larger boat. The combination of adequate service to prevent
overloading and correct heating equipment makes electric heat on a boat safe.