PREVENTIVE POWER PLAY
magine hand cranking your engine, or retrieving your anchor using a manual windlass, or lighting kerosene navigation lamps every night. While you might curse it from time to time, your vessel’s electrical system makes cruising far more enjoyable, leisurely and safe. In my experience, failures are nearly always avoidable, and thus failure prevention must be proactive; the best approach is to go looking for trouble before it manifests itself, and there’s no time better than at the start of the sailing season.
IAt the outset of another season of sailing, follow this advice to tune up your electrical system
SYSTEMS
Batteries As providers of power for engine starting as well as navigation and communication gear, lights, fans, pumps and other systems, your vessel’s batteries are perhaps the most important part of the before trouble occurs. electrical system. Making certain they are reliable and well cared for should be a top priority. Begin by inspecting terminals; these should be tight, and free of all corrosion. To prevent the latter, my preference is for a conductive paste, such as T&B Kopr-shield, on the contact surfaces (it is not designed to be slathered over completed connections), which are then coated with CRC Battery Terminal Protector (more on cleaning and preserving electrical connections below).
Ideally, batteries should be equipped with flag terminals, vertical lead or copper plates, through which a bolt is passed to secure cable ring terminals. Under no circumstances should wing nuts be used to secure ring terminals to batteries; always use a hex nut and bolt, preferably stainless steel or bronze. Batteries relying on automotive-style round posts must utilize an adapter lug or terminal. These are available in a variety of styles; however, those that rely on a through-bolt, rather than a cast-in-place stud, should be used. In order to keep resistance at a minimum, no more than four ring terminals should be placed on any single stud, and ideally, less. If any one of your batteries’ terminals supports more than four ring terminals, consider installing a bus bar to which some can be moved.
Because they convey especially high current, and since they are typically not equipped with overcurrent protection (i.e., a fuse or circuit breaker), battery cables used for starting purposes must be routed and protected with special care. As a result of the energy stored in the battery, and the diameter of the cable, a short circuit will spell almost certain disaster because the heat generation will quickly ignite nearby timber, fiberglass, insulation and so forth. The positive cable leading from the battery, or battery switch, to the engine starter, must be routed out of harm’s way, where it will not be repeatedly stepped on, or have gear stored on or dragged over it. Other than its connection to the starter, it must not touch the engine, transmission or motor mounts in any way, and it should be sheathed.
Unless contained in a box, positive battery terminals, as well as those on the starter post, must be fully insulated or enclosed. An ill-fitting rubber boot or cap is not sufficient; if any part of the terminal or stud is exposed then additional insulation must be installed. Starter cable runs and exposed terminals present a very real short-circuit danger; don’t dismiss these guidelines as