The Westlake Pirates

First, a brief study in battery charging, since I now know way more about it than anyone really should need to if they don't work at the Energizer corporation. Batteries (especially the large, acid-filled 12V type found in boats and cars) are easy to recharge, but somewhat finicky in their ability to take energy. When drained, batteries charge very rapidly, converting lead sulfite back to lead metal and sulfuric acid liquid solution. As the batteries near capacity, their ability to take up energy dramatically decreases. When they reach capacity, they are only capable of taking a very tiny charge, often known as trickle charge. Modern chargers are designed to compensate for this and charge batteries at an optimal rate no matter what their current capacity is. Thus they charge very rapidly at the start, then drop down the input as the battery nears full. Old chargers (like the one that was 30 years old and installed on the boat), didn't have this sort of technology and simply pump a constant voltage into the battery regardless of the current charge. This is where the problem with our charger was - it continued pumping voltage into the batteries even after they had reached capacity, thereby heating the batteries and causing them to vent sulfuric acid gas and water vapor, which in turn caused their capacity to decrease and the system to become yet more strained. My temporary resolution for this problem was to run the charger until I detected the faint odor of sulfuric acid, and then turn the system off until the batteries showed signs of being drained. This worked acceptably well for many months, other than the hassle of needing to go into the engine compartment to turn the charger on and off, and occasionally needing to top-off the batteries with distilled water to replace what had been vented. Finally, one of the two batteries no longer took any charge and showed signs of stress and metal fatigue, along with serious loss of fluid. This is harmful and could eventually lead to a fire, so it was time to replace both the batteries and the charger.

Chargers are fairly inexpensive (especially for our needs), so it looked to be a straight-forward swap and replace job. Of course, with this boat, nothing is ever straight-forward. Boats generally have two 12V DC needs - engine start-up and cabin power (lights, toilet motor, etc). Usually, these power draws are separated by fancy switches that either preserve one battery for motor needs (to ensure you never over-drain the system with house needs and then have a dead engine), or let you swap the full system from house to engine, or both. Our boat, instead, had a thoroughly convoluted system with charger lines running directly to engine starters, switches that activated nothing, wires spliced and covered in electrical tape, and other things that still boggle my mind. This all needed replacement as well.

As it was set up, many of the wires were either useless or miscolored (black wires with yellow tape substituting for red, for instance.) I decided it would be easier (and safer!) to just get a spool of 2 gauge red wire and start fresh with the hot lines. This required a lot of stripping and attaching post caps, some of which is detailed in the photos below.

Above are all the parts purchased for this repair. A is the new charger, B is the spool of new wire, C are the post caps to be clamped to the wire, D is a fluid tester to ensure the new batteries are holding charge, and E is bronze wool... which is identical to steel wool but works better in wet areas because the flakes that fall from it won't rust.

Here's a stripped wire and the cap that's about to be clamped to it. I ended up using my channel locks to crimp the caps on because my wire stripper/crimper didn't go up to a large enough gauge. This had to be done ten times, on five separate wires.

Here are the short (all less than one foot long) wires, and the long wires (one 20 feet long, the other eight feet long) after all the crimping and taping was completed and just prior to installation. Compare to the old parts (below) that were removed, and especially note the bizzare three-way split that is covered in yellow electrical tape in the middle of the red wires.

Overall, the installation went quite smoothly and without any serious problems. It took a little bit of plotting and planning to rewire the system in a more logical manner, but now one switch controls the house power (which can draw from one battery, the other, or both) and the other switch controls engine power (again from one, the other, or both.) The most difficult aspect of the entire installation was installing the new charger in a fairly inaccessible location behind and above the port engine, which required a few contortions on my part until the screws finally bit into the wood and held the system up.

Here's the new switch wiring from the rear. The batteries are to the left of this picture, with the house distribution controlled by the top switch and the engines from the bottom one. The 120V AC outlet at the top of the picture provides power to the battery charger when we're plugged into shore power, and the metal bar at bottom left is the DC electricity return collector.

Here's the new charger, installed and powered up. You can almost make out the outline of the old charger (which was about 50% larger and lot deeper)... the pencil line that runs above the charger was the level line that the old charger was installed in line with.

So everything is now wired up nicely (at least in the rear of the boat... the wiring under the helm is another story...), and the new batteries and charger have behaved perfectly since this work was done in early November. Line off one more task on the to-do list!