How to keep the sailboat engine electrical systems functional. There are a variety of maintenance philosophies used in commercial and offshore-based rigs and ships. The traditional and most accepted is the Planned Maintenance System (PMS). This is based on maintenance tasks based on time intervals, either set periods or operational hours, and is still a useful basis for maintaining equipment. In most cases the only planned maintenance undertaken is engine oil changes based on running hours. The previous FMEA exercise allows the implementation of what is called Risk Based Maintenance and Inspection. We have evaluated all the areas most critical to boat operation, so the maintenance strategy should be centered on this. For example we know that the main failure causes are poor connections so routinely checking and tightening them reduces the failure rate. As a start point perform the recommended maintenance on all critical equipment and systems.
All connections on alternators, starters, engine blocks, batteries should be check tightened every six months, it is an easy task and results in fewer intermittent and complete failures. It is as not as onerous as it seems, and will pay dividends. Remember to switch all power off before you start the exercise.
Starter Motors. Starter motors have low failure rates, as actual operating hours are relatively low in comparison to motor vehicle applications. Failures are usually dependant on operational frequency with seized bearings, or stuck brush-gear being the major failure causes. Regular operation reduces failures, so running the engine regularly has positive advantages. In addition this will generate heat, which assists in displacing moisture within the windings. Starter motors should be cleaned or overhauled on a regular basis, ideally not exceeding two years. I usually take it off, take it to my favorite automotive electrician, and back in the same day. If your boat has not had the starter out in years then a service is a good precaution before you head off.
Alternators. Alternators have quite a low failure rate, as actual operating hours are also relatively low. Failures are generally caused by diode failures, or overheating, in particular with fast charge regulators and oversized battery banks. Alternators should be cleaned and overhauled on a regular basis, ideally not exceeding two years. Consider a higher output rated alternator to reduce overloading and heating. Again it is cheaper to take it to an automotive electrician and have it overhauled before you set out.
Batteries. Batteries generally have the highest failure rate of all components. This is not failure in the true sense but due to either inadequate charging with resultant sulfation, lost capacity and failure, or flattening of the battery with subsequent damage. In most cases this is due to poor systems design or human factors. The second highest failure cause is inadequate inspection and topping up of electrolytes, with resultant plate damage. Consider different batteries such as AGM types with lower failure rates, improved charging characteristics and elimination of the human and maintenance factor. A consequence of the tragic Sydney – Hobart yacht race is a coroners recommendation for installing only sealed batteries. All these are good reasons to upgrade and improve overall systems reliability. More sailboat engine advice and information on boat charging systems.