Preparing your boat for the summer – Electrical

Now that the long nights of winter are getting shorter, it is time to start thinking about getting your boat ready for launching. Yes, it is over two months away, but these things have a habit of creeping up on you. If, during your preparations, you find that there are problems requiring professional attention, leaving it any later may mean that there is no-one available to do the work. Following is a checklist which may be used before the new season.

Batteries: The storage media for your electrical energy, one of the most critical items on your boat.

Check security of straps or other hold down devices. Remember, these are supposed to retain the battery in the event of a knockdown or worse. Remove the battery terminals, clean with sandpaper or emery paper, re-fit, tighten and coat with silicone grease or petroleum jelly (Vaseline)

Check level of electrolyte in cells, if possible (some batteries are sealed). They should be topped up with de-ionised water, available from motor factors, to 10mm above plates, do not overfill.

If there are one or two cells that have dried, exposing the plate, the battery is probably at the end of its life.

Check that the batteries are fully charged. If you have a hand held voltmeter, checking between the positive and the negative posts, with the battery at rest for a couple of hours (with no charger connected), should give a reading of 12.7Volts DC. Down to about 12.5Volts will be OK, anything lower and the battery should be fully charged before use.

Bilge Pumps: Something a lot of people never think of, until it's too late. The electric bilge pump pumps water, and contaminants, from your bilge over the side. When it is left over the winter, with nothing to pump, the coating of contaminants may corrode or jam the impeller. The float switch may also get a bit sticky. The easiest way to check its operation is to add fresh water to the bilge until the pump operates. If the pump is the combined pump/float type and is sticking, the complete unit must be replaced. If the float switch is separate, it may be freed up by moving it up and down a few times. If this is the case, ensure to check it on a regular basis, if in doubt, replace it. All connections in the bilges should be made using crimp connections with heat-shrink glue filled crimps to avoid corrosion.

Anodes:

Anodes should be checked for integrity, but don't forget to check that the bonding conductor (minimum 4mm) within the boat is still in place. It is not unknown for this to break, or more commonly, corrode, leaving the hull anode unable to do its work. Engine, gearbox, shaft and main raw seawater inlet fitting bonding connections should also be checked. The above information applies to GRP and wood hulls, steel and aluminium hulls have different and more stringent cathodic protection systems which should be checked by a specialist.

Engine: The security of starter motor connections should be checked. Before doing so, switch off or disconnect batteries. Check that the nuts holding the positive supply, large cable usually red, and the negative supply, large cable usually black, are tight. The positive cable will be connected to the solenoid on the starter motor, the negative may be connected to the starter motor, or to the engine block. There will also be some Lucar or push-on connections on the solenoid, these should be checked for security. Check also the connections to the alternator, again large red cable, there may or may not be a large black cable as well. As with the starter solenoid, there may be Lucar connections.

Check condition of alternator belt. This should be tensioned so that you cannot rotate the alternator fan pulley with your hand. If the alternator is covered in a film of black dust, the belt is slipping. Inspect for cracking and nicks in the belt. If present, replace the belt and remember to check the spare belt as well.

After the boat is back in the water and the engine started, check that the battery voltage increases to at least 13.5Volts, to ensure that the alternator is actually working.

Shore Power: The shore power lead, plugs and connectors should be checked for damage, terminal corrosion and security of connections. A smear of petroleum jelly or silicone grease will help prevent corrosion and arcing on connector pins. Damage to shore power leads should be repaired, remember, this is 230V AC electricity and is dangerous. If possible, the cable should be cut back to eliminate the damage. Repairs with insulating tape should never be carried out. Insulating tape is useless when used outdoors, and often when used indoors as well. The only use I have found for it is preventing blood contaminating surfaces when the first aid box is not to hand and I have been a bit careless stripping a cable with a knife!

Lights: Check operation of all navigation, steaming, anchor and deck lights. Check cables where they exit through the mast have grommets or some other anti-chafe device in place. If you need to replace any lights, a light coating of silicone grease or Vaseline in the contact pins will help to prevent future corrosion.

This should cover most of the items that, in my experience, cause problems during the first few days of the season. It is not an exhaustive list as all boats are different.

Enjoy the Season!