Electrical, Battery Monitor, Part I: Analysis and Installation

The battery monitor, installed in Oystercatcher
Battery banks are the foundation of the DC (direct current) electrical system on a cruising sailboat. To maintain these banks, the owner must charge them on a regular basis, usually on a daily basis. To ensure that he is charging them not too much, not too little, but just the right amount, he needs a battery monitor. Of course there are awkward and inconvenient, and not wholly reliable ways to get around this, but who wants to be bothered with this on a regular basis? Why not just check the monitor and know right away the status of the charge? Perhaps it is the cost of the monitor, more than anything else, that turns some people away. I did the research, and I concluded that, to me, it was worth it. I'm not going to go into the details of the Victron brand monitor that I purchased. Instead, I will refer you to the article on this subject by Maine Sail on his Compass Marine website. The purpose of the present article is to describe the steps I took toward the installation and wiring of this particular monitor as part of the larger project of rewiring Oystercatcher, my Ericson 25.
Victron brand, BMV 600 battery monitor
In the rewiring of my boat, I decided to put the new primary battery bank, i.e., the house bank, in the location of the original bank - the center of the lazarette, directly above the bilge. For the secondary bank, i.e., the reserve bank, I installed a plywood shelf on the port side of the lazarette. It's the one to the right in the picture below.
My rewiring plan (that I created after months of research, tedious computer-based labor, and countless trips back and forth to the boat) called for the installation of two, Trojan brand, T-125, 6 volt, golf cart batteries. These deep-cycle, flooded-lead batteries, wired in series, so as to create a 12 volt system, would constitute the house bank. For more on this subject, see my article, "Electrical, House Bank."
For the secondary bank, i.e., the reserve bank, I would use a Trojan SCS225. This deep-cycle, flooded-lead battery, being 12 volts, would stand alone. For more on this, see my article, "Electrical, Reserve Bank."
The Victron brand battery monitor, as I said, indicates the state of charge (among other things).
For the charging of the battery banks, I would rely upon an AC powered battery charger. Specifically, I would use the Iota 45 by Iota Engineering. This 45 amp model that I purchased was the DLS-45 with an IQ4 Smart Charger Controller. I would install this charger just above the ice box. In the picture below, you see me lifting the splash shield that I constructed to protect the charger. For more on this project, see my article, "Electrical, Battery Charger."
The Iota 45 charger would charge both banks simultaneously. To make the Iota 45 do double-duty, charging both banks at the same time, I would use the Blue Sea Systems brand ACR (Automatic Charging Relay).
A 4 AWG (American Wire Gauge) cable would run from the Iota 45 to the House Bank Positive Bus. From this bus, there would run another 4 AWG cable to the stud pictured on the left below. On the stud on the right, there would be another 4 AWG cable. This one would run to the Reserve Bank Positive Bus. Joined in this fashion, the Iota 45 would charge the House Bank, and at the same time charge the Reserve Bank. For more on this subject, see my article, "Electrical, Main DC Circuit."
The DC electrical panels, when I purchased the boat in 2009, were located on the port side of the galley. Although I would remove all of the old electrical system (see, "Electrical, Original"), I would stick with port side of the galley as the home for the panels, switches, and other important items. There were two factors that led me to use this as the home for the above mentioned items. First, there was the issue of water. I preferred the electrical system to be close to the stove rather than close to the sink (on the opposite side of the galley). The stove area, of course, was not ideal, but I would protect the system while cooking by shielding it with high-tech, fireproof cloth that I could snap into place. Secondly, there was the issue of weight. The house bank was located in a good place - low and centered over the bilge in the lazarette. On the starboard side of the transom would be a Yamaha 9.9 high thrust outboard motor. This motor, being a 4 stroke, was significantly heavier than the 2 strokes of old. Given that this motor would be on the starboard side, it made sense to me to locate the reserve bank on the port side of the lazarette. You always want to minimize the distance between the batteries and the major components of the system - the battery switch, the main DC breaker, etc. Therefore, it made sense to put these major components on the port side.
It might not look like it would be possible, but this small bulkhead, where the old battery switch and DC panel were located, would house six of the components of the new system.
Before I could install any of these components, I needed to create cardboard mock-ups.
Much of the interior of the boat was trimmed with mahogany. Therefore, I wanted these components to be trimmed in mahogany. Why not make the boat look classy? For more on how I obtained this mahogany see my article, "Electrical, AC Distribution Panel."
The three trim pieces below would be devoted to the battery switch, the battery monitor, and the DC main circuit breaker.
The dry-fit of the trim pieces.
The trim pieces with their corners now rounded to give them an appearance more suitable for a boat.
I began by installing the AC distribution panel and then the bilge pump switches. After this, I moved on to the battery switch. Having installed this battery switch, I turned my attention to the Victron battery monitor. First, with the mahogany trim piece removed from the boat, I cut a hole through it with a hole saw. Then I reinstalled the mahogany trim piece and used the hole in the mahogany as a template for cutting the hole through the bulkhead.
The hole through the bulkhead, just after I had cut it.
The Victron battery monitor has a square-shaped, white piece of plastic that is used to secure the monitor to a bulkhead or other flat surface.
It also has a threaded, white plastic ring that screws onto its backside. The ring or bezel is helpful for snugging up the monitor against the bulkhead.
Below we see the monitor in place between the battery switch and the DC main circuit breaker.
The monitor comes with a gray, plastic trim piece that snaps into place over the square-shaped plastic mounting piece.
There is more to the installation of the Victron battery monitor than this. For instance, there is an important piece of equipment known as the shunt that must be mounted near the battery bank. Given that the subject of the first part of this two-part article is primarily concerned with the installation of the battery monitor itself, it seemed appropriate to me to address the installation of the shunt in the second part of this article, the part that is concerned primarily with the wiring of the device. 
This ends this posting on my installation of the Victron battery monitor in Oystercatcher, my Ericson 25.

Galley, Sink Cabinet, Part 8: Lower Storage Area

The lower storage area with the cleat and rack installed
On a small cruising sailboat you have to make the most of what little space is available to you. It was because of space considerations that I had decided to modify the sink cabinet on Oystercatcher, my Ericson 25. For most of this project, I had focused my attention on the upper space, i.e., the space that would house the plates, bowls, glasses, and other items. As much as I wanted to complete my work on that space by permanently installing the shelf and partitions, I thought it wise to be patient and take some time to modify the space beneath the shelf, so that it would be usable space and not wasted space. The problem with this space was the same problem with so many other spaces on the boat that I had already addressed - how do you create usable space out of a space that is not square (as it is in land-based structures), but is instead curved? How I addressed that problem in the lower storage area of this boat is the subject of this eighth part of my twelve-part article.
I knew that one of the things I wanted to store in this space was garbage bags. You can't ever have too many of these things. I planned to store bags of garbage in the lazarette. In keeping with my experience aboard tall ships, I planned to triple-bag each bag of garbage, in order to prevent juices, odors, and other unpleasant things from escaping their nasty confines. Before I had ever seriously contemplated permanent modifications to the lower storage area, I attempted to devise some simple storage solutions for the garbage bags. As you know, plastic garbage bags are sold in rolls and are packaged in cardboard boxes. I had no intention of bringing the cardboard boxes aboard the boat. Boxes take up space, they absorb moisture, and they end up doing nothing more than creating more trash. With the rolls of garbage bags in hand, I placed them into the lower storage area. Predictably, they sought the lowest part of the storage space (the space, in the picture below, at the bottom left). Remember that the picture you see below is the end-result of this lower storage area project. Before this, there was nothing in this space except the bronze seacock. It's hard to convey to you how much wasted space there was in this lower area, but believe me, there was a lot. I really needed to do something more with this space than store a roll or two of trash bags in lowest part of it. I needed to create shelves of some sort to keep things organized.
My first thought was to make use of the small wooden storage box that was in the boat when I purchased it back in 2009. The previous owner had screwed this box to the bulkhead in the main salon. I have no idea what he used it for. In my opinion it served no good purpose, and I removed it not long after I bought the boat.
My thought was to screw this box to the bulkhead, inside of the cabinet. Despite its size, it fit into this space, but just barely. When I placed a roll of trash bags into the box, I discovered that the box was several inches too large for the average-sized roll of trash bags.
This led me to consider a certain binocular rack that I had purchased at an earlier date but never used. The Sea Teak brand rack, which you see below, I purchased online, thinking that it would be the right size for the average pair of binoculars. After I had received the rack, I discovered that it was much larger. This was the type of rack intended for larger-than-normal, image-stabilization binoculars.
As it turned out, this binocular rack provided a perfect fit for the roll of trash bags. In the picture below, you can see that the rack contains a roll of black, 30 gallon trash bags, and a roll of white, kitchen-trashcan-sized bags.
The binocular rack solved the trash-bag storage problem, but I was still left wondering, if it might be worth it to create some other sort of storage area behind the rack and the bronze seacock.
I began by toying with the idea of creating a shelf in this area. I didn't toy with this idea very long. The mock-up revealed that a shelf would considerably reduce the size of the storage area. Moreover, it would require a fiddle to keep the stored items from sliding off of the shelf. The fiddle, protruding upward from the edge of the shelf by 1.5 inches, would further reduce the size of the storage area.
It was then that I began to think that a cleat would provide the maximum amount of storage space. A cleat would allow me to toss small items up into that space. Gravity would keep them in place, especially if the cleat was large enough. I started by placing a scrap piece of 2 x 4 Douglas fir in this space. This appeared to me to be too small, especially since I planned to cut off the upper portion of it in order to make it level.
Putting this piece of wood aside, I grabbed a scrap piece of 2 x 6 Douglas fir. This to me looked like it would do the trick.
The 2 x 4 scrap piece already had a 25 degree bevel on it. I used this as a basis for judging how much of a bevel I needed to cut on the 2 x 6.
I determined that a 20 degree bevel would probably be the correct one, and with my Makita brand miter saw, I made the appropriate cut.
Dry-fitting the 2 x 6 into place, I determined that the 20 degree angle was not correct. I went back to the saw and recut the bevel to 22 degrees. This one was as just right, or as close to just right as I could get it. This bevel of 22 degrees allowed the cleat to stand plumb, at least from a port and starboard point of view.
By "plumb," of course, I mean "straight up and down." Now that the cleat was plumb, port to starboard, I needed make it plumb with regard to its forward and aft orientation.
Using the forward bulkhead (pictured left) as a vertical reference, I used a tape measure to mark points on the Douglas fir that were equidistant from the bulkhead. I then removed the cleat, grabbed a straight edge, and drew lines through the points, thus making the lines you see pictured below.
Next, I used a level to mark a level line along the side of the cleat.
I then used this level reference line to draw a parallel line higher up on the cleat. The goal was to maximize the size of the cleat.
Making the cut.
Nice and level.
I didn't take a picture of it, but I used a carpenter's square to check my plumb marks before making the next cuts. I knew that the top of the cleat was level. This enabled me to double-check my plumb lines on either end of the cleat
The finished piece, after making the cuts along the plumb line marks.
Oriented in this fashion along the flat surface of the cutting tray of the saw, the 22 degree bevel along the bottom of the cleat causes the cleat to tilt away from the viewer.
The finished piece, dry-fitted into place. Note that at the bottom left of the cleat (as seen in the picture below) there is a small gap between the bottom of the cleat and the hull. This gap is there because a small piece of the Douglas fir chipped off of the cleat when I was cutting the bevel. This would not make a difference after I had applied thickened epoxy in this space.
I wanted to soften-up the top side of the cleat, so my next move was to take out the router and install a round-over bit.
The top side, after I had hit it with the round-over bit.
I also decided to hit the sides of the cleat. I had used the router in a similar fashion on the other cleats I had made for this boat. See, for example, my articles on the modifications I made to the V-berth and the lazarette.
One more dry-fit.
The next step was to give each side of the cleat two coats of epoxy. In the picture below, you see one of the sides after a single coat of epoxy with the grain of the wood still visible.
Here's what two-coats of epoxy looks like. This is the flip-side. The drip marks are from the two coats of epoxy I put on the other side the previous day.
Here's an even better shot of what two-coats of epoxy looks like.
After I had allowed the epoxy to fully cure, I thoroughly sanded the cleat with 40 grit paper on a quarter-sheet sander. The hazy, smooth surface is a sign that the piece has been epoxy-coated and sanded correctly.
Back in the boat, I again dry-fitted the cleat. This time, I marked the hull with a black Sharpie marker. This was the area that I needed to grind in preparation for gluing the cleat to the hull with epoxy and cloth.
A 30 grit sanding disc on the angle grinder made quick work of this job. I took care not to go too quickly, however, since it is not hard to grind too deeply into the hull.
In the areas that the grinder could not reach, I used my Rockwell Sonicrafter oscillating tool (with the triangular sanding head attached) and 50 grit paper.
I also sanded the area around the old hole for the conduit for the VHF coaxial cable. This hole I planed to cover with cloth.
After vacuuming up the dust with the Shop-Vac, I wiped down the hull with xylene to make sure it was free of wax and other debris.
The xylene cleaned the area very well. It also removed all the marks I had made with the black Sharpie marker. Therefore, I had to dry-fit the cleat one more time and remark the hull.
Before I mixed-up the epoxy I made sure to get all of the cloth ready by cutting it to the proper size. I used scrap pieces of 6 ounce cloth for this.
Having cut the cloth, I mixed up the first pot of epoxy and wet down the cleat and hull in preparation for the gluing of the cleat to the hull.

After I finished wetting out the above-mentioned areas, I added colloidal silica to the pot, in order to thicken-up the epoxy and make it suitable for gluing. As I had done with other cleats that I had installed in other areas of the boat, I allowed the epoxy to heat up as much as possible before applying it to the hull. This would make it more sticky than it already was, and it would help to keep the cleat from sliding out of place due to the slope of the hull. If you want to read more about this technique of "sweating the pot," see my article on the installation of the cleats in the lazarette.
It was cooler than usual in the Carolina Lowcountry when I did this job, and for this reason, despite the fact that I had allowed the pot to sweat, the cleat did not immediately grab the hull. For this reason, I had to use the piece of wood and the pencil that you see in the picture below to keep the cleat from sliding down the hull.
On the front of the cleat, and on the back (as you see pictured below), I applied fillets. These fillets would provide strength, and they would allow the cloth to bond more easily along the joints between the cleat and the hull.
After it seemed that the epoxy had kicked and the cleat was now sticking to the hull, I laid out the cloth that I had earlier cut. For each side of the cleat I had prepared two layers of cloth, one large, one small.
Below we see the front of the cleat after I had applied the two layers on that side.
Here's a shot of the backside with both layers of cloth. At this point, I had not yet applied the final layer of cloth - a single layer that would lap over the top of the cleat. This final layer would bond the front to the back and it would protect the top.
After I had applied the two layers of cloth to each side of the cleat (and the layer of cloth on the top that would tie it all together), I made some measurements and discovered that the cleat, much to my dismay, had slowly slid down the hull, and settled in a spot that was 3/4 of an inch off the mark. By this point the epoxy and truly started to kick and when I tried to move the cleat back up the hull by 3/4 of an inch, it put up some resistance. To aid me, and to make sure that this cleat would not move back down, I grabbed two screwdrivers and shoved the cleat upward with much force, wedging the screwdrivers into place. I could not obtain 3/4 of an inch worth of movement, so I had to settle for 1/2 of an inch. Yes, once this stuff starts to kick, it gets really stubborn, and there is little hope of winning a battle against it unless you resort to drastic measures.
The next day, after the epoxy had cured, I returned to the boat, curious to check out my work. I was pleased to see that the cleat did indeed create additional storage space out of a space that would otherwise have been wasted. In the picture below you see a box of blue nitrile gloves tucked away behind the cleat. This box is about the size of a box of facial tissues. I wouldn't put a box of gloves or a box of tissues in this space. You do, though, get a sense of the size of this space from these examples.
Next I wanted to see if the binocular rack would still fit into the space along the forward bulkhead where I had planned to install it. Fortunately, despite the fact that the cleat was a little bit lower than I had originally planned for it to be, it did not prevent me from fitting the binocular rack into its designated space.
This panoptic view emphasizes just how much space would have been wasted, if I had never made these various modifications to the sink cabinet.
Satisfied with the dry-fit of the binocular rack, I removed the main shelf and checked the cleat for level. Despite the movement that occurred during the gluing of the cleat, the cleat was still almost perfectly level. Note that there is a larger gap on the right of the cleat (as seen in the photo below) than on the left. I had originally glued the cleat into place with equal spaces on each side. The larger gap on the right resulted from the cleat slowly sliding left due to gravity during the glue-up. I should mention that I intentionally cut the cleat short, so that these gaps on either side would exist. These gaps, of course, would allow for ventilation and for the free flow of water (in the form of condensation on the hull) during the colder months.
The only thing that now remained was for me to sand the cleat. The sanding would remove the burrs and sharp edges of the cured epoxy, and it would create a surface that would more readily accept the paint that I planned to apply to the entire cabinet at the end of the project. Before I could start the sanding, I had to install a new triangular sanding head on my Rockwell Sonicrafter oscillating tool.
From time to time it's necessary to swap an old one for a new. The Velcro surface of the head degrades over time due to the repeated friction and pressure from sanding. These replacement heads cost about five dollars a piece.
The three tools that I used for the sanding job were the same three that I had used on so many other sanding projects on this boat - the quarter-sheet sander (with 40 grit paper), the Rockwell (with 50 grit paper), and the Dremel (with a 50 grit sanding drum).

Installing this cleat in the lower storage area was not a welcome digression from the main task at hand, but it was one that I was glad that I had made, after it was complete. That additional storage area would be there whenever I needed it, and the binocular rack, which formerly served no purpose, would now fit well into this space and would serve as a handy pocket of sorts for at least two rolls of trash bags.
This ends this posting on the modifications I made to the lower storage area of the sink cabinet on Oystercatcher, my Ericson 25.