A new battery system

Glacier Gem anchored in a creek on the Mississippi River prior to the start of the Massey’s circumnavigation.
Glacier Gem anchored in a creek on the Mississippi River prior to the start of the Massey’s circumnavigation.

When we found our project sailboat dream-hull in a remote Southeast Alaska village, there was essentially no useful batteries and no electrical system installed. We had to determine what we wanted for batteries and then install them and build an electrical system around it. 

The electrical items that Glacier Gem, our aluminum schooner, did have were limited to two large, unsecured batteries connected to a rusted-out and hotwired engine gauge panel. None of the gauges worked and there was no key. The giant batteries were best suited to a farm tractor or to a bulldozer than to a seagoing vessel. If you jiggled the battery ground wires, you could start the main engine…maybe. There was a hole cut in the aluminum deck through which a household electrical cord passed from a dock to the interior below for plugging things in. That is as close to shore power as it got. There was even a sea otter living inside the hull. He liked it so much, he brought in a seagull and a Dungeness crab. I found them hidden under a mattress when I surveyed the boat.

The final electrical panel setup with elements noted
The final electrical panel setup with elements noted

We’ve come a long way since then. My wife and I spent more than four years completely rebuilding the Colvin Gazelle design. There is no more sea otter habitat and there is no more hole in the deck. We finished the rebuild project and left nine months ago on a circumnavigation. 

There were many factors that had resulted in that original hull condition. The shipyard commissioned for initial construction went bankrupt. A second shipyard worked on the boat but didn’t complete it, then the first owner met a premature death. The second owner wanted to see that the boat was finished and actually sailed, so he sold it to us. The hull needed everything from ballast to rigging… including, of course, batteries and an electrical system.

Before we started the battery replacement project, we counted the draw of every item we planned to have onboard and priced different components to build the system. We wanted to optimize our setup for the overcast and rainy conditions found in the northern latitudes of Southeast Alaska. We ended up engineering it with the minimum requirement to continuously operate a chartplotter/radar combo and our marine freezer for more than 48 hours, with the running lights on, and without a charge source. We also designed it to still be able to start the main engine after that 48 hours had elapsed. 

We were pleased to find that our power needs were quite minimal, and that it was economically feasible for us to make our own electrical system. In addition, there were many technical guidelines available from sources such as ABYC, USCG, and the Code of Federal Regulations (CFRs) to help us along the way. 

The boat’s batteries are located in port and starboard battery boxes on either side of the engine.
The boat’s batteries are located in port and starboard battery boxes on either side of the engine.

Two battery banks
The DC system we constructed consists of two 12-Volt circuits to include a house and a start circuit. Both circuits are identical and each has two Trojan T-105 lead-acid 6-Volt batteries wired in series. These batteries are quality made, relatively inexpensive, and are readily available. Each circuit provides 225 Amp-Hours (450 total Amp-Hours). The batteries weigh 124 lbs per circuit. We placed the batteries at an accessible location in our engine room which is slightly below the waterline with one circuit on the port side and the other circuit on the starboard side to balance each other. The batteries are secured inside commercial grade Noco Marine battery boxes that can contain the batteries even upside down. 

Our house and start batteries are exactly the same, but we use them differently. The house side powers everything outside the engine room whereas the start side powers everything inside the engine room. We opted to double our storage capacity instead of using specific starting batteries for the limited times we crank on the engine. This has the potential to shorten the lifespan of the batteries, but we have not experienced any noticeable difference.

We also have one additional circuit separate from the house and start switches. That circuit has a fused alarm panel switch to independently operate automatic bilge pumps, a bilge pump cycle counter, high water alarms, and a general alarm from the start battery bank. This allows us to minimize fire risk and automatically dewater when the vessel is unattended. In other words, the freezer is turned off but the bilge pumps still work.

A closeup of the solar/inverter housing.
A closeup of the solar/inverter housing.

Battery charging with solar
To keep the batteries full, we charge mainly using solar energy but we also have an engine alternator, shorepower, and a portable generator available. We never plug into shorepower, and never use the portable generator. We use an auto charge relay to keep the batteries isolated while still charging both banks from a single charge source. We mainly use the solar panels to keep the batteries topped off and just don’t find the other power sources necessary. 

We love the solar panels and can’t say enough good things about them. The solar array consists of four 160 Watt monocrystalline panels wired in parallel and connected to a solar charge controller. A total of 12 Volts, 640 Watts, is produced by the array. The charge controller handles up to 150 Volts, 60 Amps. One feature of our system is that the solar array is relatively large when compared to the battery storage capacity. This allows us to recharge quickly in those situations where sun energy is minimal, like on a rainy day, or when it has been snowing.

Glacier Gem has five watertight compartments dividing the vessel. This has the potential to make running wires complicated . Each wire needs a hole at the bulkhead which would then make it not watertight. Our solution was to install Scanstrut watertight seals where electrical wiring passes through the bulkheads. The seals maintain the watertight integrity of the compartments while still allowing power to pass through them. To avoid running hundreds of wires through each seal, from end-to end on the boat, we chose to supply power to a switch and fuse block in each compartment. For example, the overhead LED lights in our anchor locker at the bow, are connected to a fuse panel in the bow, rather than stringing a wire for those lights along the entire hull length. 

One of the more difficult items to connect was the masthead anchor/steaming light combo. That light required multiple wires to pass through three bulkheads seals, a deck seal, and travel to the top of the foremast while having the toggle switch in the aft most cabin. It even required welding a tube inside the mast to prevent the wires from dangling freely inside. There’s nothing more annoying than ropes or wires clanking on the inside of an aluminum mast where you can’t reach them! To make things a bit more challenging, our masts are fit into tabernacles and are designed to fold on deck allowing us to fit under low bridges. That means the wiring has to permit the mast to rotate accordingly. Interestingly, we installed a duplicate anchor and steaming light on a separate rotatable pole for operation when our masts were lowered. We have our sights set on the European canal systems, and this feature allows us to comply with vessel lighting schemes.

No dodging responsibility
A result of fabricating your own system is that there’s no one else at fault when things fail. When there is a problem on our boat, I’m always the one responsible. There’s no one else to blame. I made one of those mistakes when installing the inverter. The inverter has a huge electrical draw and it’s a long run from the house battery. When I calculated the draw and wire size required for the run, I put the wrong numbers into the formula. I did not realize my error until I completed and tested the circuit. The result was that the inverter would trip, display an error code, and not supply power. It took some head scratching to figure out that my calculations were the cause of the problem. I had used much too small of an input wire and the inverter was struggling to get enough electricity, like trying to breathe air through a long straw. Large diameter marine grade wiring isn’t cheap. It was an expensive mistake and an expensive solution but no harm was done. I recalculated the problem, found my error, and fixed it by installing a proper sized wire. 

Fortunately, we have been without any electrical problems for the last three years. We have been living onboard continuously for the last nine months. We rarely go to marinas and generally prefer to anchor out on our own, in solitude. This way of living requires us to be in-tune with what is happening in the environment around us. We feel each wind shift and every wave surge. When it is sunny outside, we have full power available. When it is cloudy or rainy, we cut back our power usage. 

Some places don’t have great sunshine and sometimes the weather makes it tough to keep a full battery charge. Those factors force us to adjust our way of living. When we traveled down the Mississippi River and tied off to trees in a Yazoo River drainage ditch in Vicksburg, Mississippi, the tree cover was too dense to charge the batteries. Each morning we needed to scrape the frost off before the panels would work at all. We liked Vicksburg so much that we stayed for four nights, even though it meant restricting our LED interior light usage at night and only charging our cellphones once. 

One of the two Noco Marine battery boxes.
One of the two Noco Marine battery boxes.

Clearing the array
Our solar array is installed horizontally and positioned under our main boom. It is less than ideal for capturing full sun. It would be electrically better to position the panels directly facing the sun, and be rotatable, but like many boats, our deck layout does not support this. I’m likely to accidentally break them if they were positioned differently. We chose to protect the panels as much as possible by installing them in this location, instead of at the most electrically favorable spot. The horizontal positioning makes it necessary to clear the panels off every time there is fresh snowfall, falling leaves, or even bird droppings. 

When it rains for more than four days straight, we find it difficult to have enough power to charge luxury items like laptops while still ensuring enough power for running our freezer. If the solar panels were angled, they would provide greater performance and would better shed rain and snow. Since our main boom rests on the panels, we slide the boom slightly to one side when in port or at anchor for a long period.  If we find ourselves needing more power, or struggling to keep up with demand, we can move our mainsail bundle in about 10 minutes to give the solar array an unobstructed view.

Our system is simple and rugged but does require regular maintenance. The lead acid batteries require checking the cell water and specific gravity to maximize their longevity. We utilize a strict vessel maintenance schedule where we check the batteries every 30 days. When checking these types of batteries, don’t forget that they produce very flammable hydrogen gas. I once saw a large battery on a tugboat explode in someone’s face after they made a critical handling mistake. They had opened each cell to add water, then caused a spark by putting a charger on it while the cells were still open. Fortunately, that person didn’t get hurt, and I happened to be shielded by an engine block. The acid ate holes in their clothing that made it look like they had been peppered by a shotgun. It only takes one of those incidents to ruin your day, or worse.

The engine room wiring diagram for Glacier Gem with the elements colored by function.
The engine room wiring diagram for Glacier Gem with the elements colored by function.

There are modern lithium batteries that are more compact, lighter, and store much more energy than our lead-acid batteries provide. They are also reasonably priced and have internal temperature sensors to automatically disconnect in the event of overheating. Even so, I still have concerns about the potential fire risk this technology can present. I’ll wait for others to be the test pilots over many years before we upgrade.

Fabricating the electrical system was rewarding, but super tedious. I chose to crimp and solder every electrical connection and to support each wire well to prevent failures. There are hundreds of connections and it took weeks to make them all. Every connection has glue-type heat shrink and is labeled and color coded. There are thousands of zip ties securing wires throughout the vessel. I am still amazed that I have over 16 cumulative hours invested in just closing zip ties! I am glad that I took the time to construct it. I now have the skills, tools, and knowledge to repair or improve it even in remote locations, if it should be needed.

In the last nine months, and more than 5,000 nautical miles underway, we have experienced a wide variety of operating conditions. In Louisiana, it was so cold that our lines froze into horizontal icicles. In the Bahamas, it was so hot that the aluminum deck would fry eggs. In Columbia, everything drips with moisture during the rainy season. Since we followed marine guidelines, and in many places exceeded them, our system has tolerated these conditions. We have a long way to go before we complete our goal of circumnavigating. One thing is certain, our system will be tested by nature many more times before we are finished. n

Nicholas and Monika Massey are circumnavigating aboard their aluminum, junk-rigged schooner which they extensively rebuilt prior to departure.