South Coast Sailboats

120V (AC) switch & 12V Battery charger, 4 Deep Cycle Marine batteries


The 120V line that goes to the duplex box mounted up in the battery compartment in the bow, is switched by a standard wall switch mounted below the final battery switch. There are three of these battery switches. The other two are mounted in one of the starboard cabinets under the bunk on that side. The way it works goes like this. Two batteries are mounted on the port side of the battery compartment. Two batteries are mounted on the starboard side of the battery compartment. There is one switch for each pair of batteries. This brings four batteries down to two circuits. The final battery switch mounted next to the control panel, brings the two circuits down to a single feed. This allows us to feed off of any single battery or any other combination. This works extremely well since our system is a straight discharge type with no means of charging while under way. As a big bonus, this also allows you to charge the batteries in pairs while being off line from the 12V circuit being used on the boat while charging discharged batteries.

Another point of information, when we carry four batteries up in the nose of the boat, this goes a long way to counter-balancing the heavy weight carried in the stern. If the water tank (that is no longer there) carried 12 gallons of water at 8 pounds per gallon, that would be 96 pounds of weight placed all the way up in the nose to counter-balance the heavy weight carried in the stern. Well, my stern is a little heavier than your average South Coast Sailboat, so, 4 - 12V deep cycle batteries at maybe 35-40 pounds apiece would add up to a maximum of about 160 pounds. This went a long way to rebalancing the boat so it does not drag its tail deep in the water like it used to. I never used that old water tank anyway, and it was always empty, therefore this was the reason that my boat used to be such a tail dragger. All that weight is mounted up where the water tank used to be. This helps even out the weight (from front to back. As a result, when sitting at the mooring, the stern usually hangs out of the water by only about 1". This then drops back down and in the water when we climb on board. This is a major plus. Before the big rebuild, I used to have in the back of the boat, 2-6 gallon gas tanks, two batteries, 1 6 hp Johnson motor, 1 anchor, plus any other equipment that I might have been storing under the floor or in the cotpit lockers, and all that was before 2-3 or 4 husky guys would climb into the cotpit. not wonder this boat used to be such a tail dragger

I have been fighting the corrosion thing for many years and when it comes to electrical systems, I have figured out a thing or two.

Some insights: When wiring in your shore power systems consider the following:

First for my wire, yes it is braided or mulitstrand wire (#14-2 with a separate insulated ground wire). This is wire meant for industrial grade extension cords. I like multistranded wire much more than solid wire (even in lighter wire) because it is more flexible, not prone to snap or break where kinked. It also when setup properly, will last for many years without degrading and corroding. All my AC wiring is made from this same type of wire. I used this for "the cattle prod" line, as well as for box to box wiring.

Second, the boxes I used were simply outdoor grade with rubber seals and snap over covers. In the two positions where I was not using special boxes, they are standard galvanized metal boxes with Stainless Steel cover plates.

Third, all connections with or without metal crimp on connectors should be coated, dipped or otherwise impregnated with something called No-Lox. No-Lox can be purchased at any electrical supplier as well as Home Depot. It is non-conductive, and is similar in appearance to automotive grease on color and consistence. It prevents the air and moisture from making it's way up into the mulitstranded wire. Cover the wire with No-Lox before adding a crimp connector, and also brush on more over screw down connections. By giving the wire ends a decent air/water seal, the corrosion is stopped before it can start. This is also a very good idea for the battery terminals.

Also, in place of metal boxes, you might consider the current crop of plastic boxes. They are of reasonable quality, won't rust, and should provide good long-term service.

To answer a specific question, why not wire directly to the boat? The simplest answer is for flexibility. I keep my boat in tidal waters (at QCYC tides rise and fall 7-10 feet, in can simply disconnect (it has give). I also like being able to coil up the line and store it way when it is not being used. The double plug line allows for very easy hookups with a minimum of fuss and bother.

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V-Berth Issue - Get out your saw!

If you started cutting, I will tell you what you will find. Not much! There was and still is a center rib which I retained. The rest of the area was occupied by a twelve gallon water
tank made of fiberglass, fiber glassed in place, and a couple of pieces of foam block. Hardly enough to provide any flotation at all in a bad situation. On my boat there was a small access panel in the top of the v-berth to access the water tank for the purpose of filling the tank. I just took the liberty to make the opening much larger, and then just adding some wood around the edges to provide support for the new panel to rest upon when in place. I my case, after cutting the top opening much larger, I than went about removing the water tank. I cut this out with a grinder. Piece after piece, until I had removed the front, back and top walls of the tank. I then grinded it back to the cloth which comprised the inner hull. At that point, I had a single center rib, and an open hull compartment the shape of the inner bow.

After getting to this point (which was very easy), I then went about templeting the base of the battery tray, installed a structural rib across the back for the base to be attached to, cut out the base tray, screwed it in place, and then proceeded to glass the shit out of it (attaching the base to the hull along both sides of the "V". This was also very easy, but time consuming and messy. Once glassed in I took a swat or two at it with the grinder just to tune up the fiberglass, and then hit it again with one last coat of glass.

After this, all I had to do was add a couple of ribs to locate the batteries, add a 120 V AC GFI Duplex outlet in an outdoor weatherproof housing, and the battery wires. To take 4 batteries down to one feed, I used three dual battery switches (Switch 1 - left side 1 & 2, Switch 2 - right side 1 & 2, then Switch 3 - Left side & Right Side down to one single feed. This arrangement allows me to couple batteries for output, or charging. I only charge up twice a season. I normally charge two batteries at a time, set up with two chargers; I charge all four batteries at the same time.

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