In Search of Electrical Independence…
Doug here,
One of the most complicated and critical systems on a boat is the electrical system. Complicated because you must maintain a system that uses 110 volt alternating current (like general household current – “110 VAC”) and 12 volt direct current (like a car – “12 VDC”). Some things on a boat such as refrigerators, air conditioners, hot water heaters and miscellaneous appliances use the 110 VAC and most marine systems such as navigation equipment use the 12 VDC. The second reason it is complicated is that you need 110 VAC to charge the batteries on the boat that produce the 12 VDC. A boat gets access to 110 VAC in three primary ways. One, by being connected to a dock and plugging into what is called shore power. Two, by running a diesel engine onboard called a Generator or Genset for short. This generator is connected to an alternator that creates 110 VAC power. Three, each main engine has an alternator connected to it that takes power from the engine and converts it into 110 VAC. The third complexity is that at times you don’t have access to 110 VAC power so you have to convert some of the 12 VDC power in the battery bank into 110 VAC using a device called an inverter so that you can keep the refrigerator and, more importantly, the ice maker working.
When we bought Gypsies in the Palace, she was very well outfitted for general use where you are frequently tied to a dock with access to plenty of 110 VAC power. However, our plans are to spend long periods of time on anchor where we have to produce all of our own power. So let me review the setup of Gypsies originally. She had 12 6-volt batteries, every two in series to create the equivalent of a 12-volt battery and the 6 resulting 12-volt pairs in parallel. This bank of 12 batteries held 1320 AMPS of 12 VDC power and is called the House Bank and is used to run the main systems on the boat. Gypsies also had 4 6-volt batteries that held 440 AMPS of 12 VDC power called the Engine Starting Bank used to start the big diesel engines and 1 battery used to start the generator’s diesel engine. The work horse is the House Bank. Gypsies has a 12.5 kilowatt generator that creates 110 VAC power but burns diesel fuel to do so. Attached to each main engine is an alternator. The port engine has a 150 AMP alternator that charges the House Bank. The starboard engine has a 120 AMP alternator that charges the Engine Starting Bank. She had a Xantrex inverter that takes 12 VDC power from the House Battery Bank and converts it to 110 VAC when we are not tied to the dock and do not have the genset running. The inverter also is used to charge the House Bank when we have 110 VAC from shore power or are running the genset. When we bought Gypsies, we thought that she was very well setup and seemed to have all of the electrical systems that we would need. When we were tied up to a dock we got all the power we need by being connected to shore power. When we were underway the big diesel engines would produce enough power to keep the House Bank charged. When we were on anchor, the generator could be started periodically to recharge the batteries. The House Bank would produce the 110 VAC power we needed when we were not connected to shore power and the genset wasn’t running.
After the first 60 days of living on the boat, it became clear that Gypsies was under-powered in several important ways. First, the inverter, which doubles as the charger for the House Bank when either the genset is on or we are connected to shore power, took too long to charge the battery bank causing us to have to run the genset about 6 to 8 hours a day to produce enough power. That is both expensive because of the diesel fuel used but also ties me to the boat for 4 hours in the morning and 4 hours in the evening. The second issue was that the alternator on the port engine was under-powered for charging the House Bank if we had started out with the bank partially discharged. It was fine to keep the batteries charged if we started out charged but not if we started with the bank run down from power usage over night. The third issue was that the 1320 AMPS in the House Battery Bank was enough for normal usage but meant that we had to recharge twice a day.
So what to do… I read lots of stuff so I began to understand the issues but not how to solve them. At this time, I was lucky enough to get some posts from the DeFever Cruisers Forum which I am a member of that dealt with this very problem. The DeFever Cruisers Forum is a group of people that post questions and answers regarding DeFever boats. Since Gypsies is a 49′ DeFever, I joined the forum and have met a bunch of people through the forum that own DeFevers. I have also learned a lot from the questions asked and the resulting answers. So the discussion that happened at about this time was about how to charge the House Battery Bank faster, one of my biggest issues. The basic answer was that you needed two inverters charging the battery bank rather than just one. The one was enough to create 110 VAC from the battery bank but not enough to charge the batteries quickly. As part of this discussion, I also met a guy named Steve Koch who owns a 49′ DeFever Raised Pilothouse named Aurora. I was introduced to him by one of the other forum members. He does mechanical and electrical work on boats. Everyone I talked to said he was great, and he certainly knows our boat since he has owned a similar boat for 13 years. I got in touch with him and, as it turned out, he and his wonderful wife Diane were only about an hour and a half by car from us and we were both stranded due to weather. So, Tammy and I rented a car and drove to where he was and met he and Diane. First, it turned out that they were two of the coolest people we have met on this journey so far and, second, Steve was unbelievably knowledgeable about all of the issues I was struggling with. We discussed my issues and he showed me how he had resolved them on Aurora. We agreed that he would do a project on Gypsies to upgrade our systems. He would swap out the one Xantrex inverter for two new Magnum inverters, wire the two engine alternators together to charge the House bank with nearly twice the power when underway, and add four more batteries to the House Bank increasing the power storage by 33% to 1760 AMPS.
As Tammy mentioned in her recent post, we spent the last week in Stuart, FL, so that I could work with Steve on Gypsies’ electrical upgrade. We got started Tuesday morning and finished up Friday afternoon. We spent a few hours on Saturday testing the system. I won’t try to describe the whole project but it was one of the most fun times I have had since purchasing Gypsies. Steve proved to be not only knowledgeable but also a great teacher. I learned an incredible amount during that 4 day period. We installed the 4 new batteries
and wired them into the system to increase the House Battery Bank from 1320 AMPS to 1760 AMPS, we ran all of the wiring needed to run the two inverters connecting them into the main wiring system,
we installed the two inverters
and put in a switch to allow me to select which one acts as the inverter
and installed two new replacement engine starting batteries. In addition, we installed two remote control devices for the inverters up on the pilothouse.
I have to tell you that I am incredibly excited about this new “electrical independence”. Since our plans for the next 2 to 3 years is to drop anchor somewhere for a week or more at a time, the ability to exist on the boat’s internal electrical system and not be tied to a dock allows us to do just that. Without this upgrade, it really was not feasible to spend more than 3 or 4 days on anchor without needing to go into a marina to “fill up” with electricity. In addition, this upgrade should save about 200 gallons of diesel fuel a month during that 2 to 3 year period.
Add comment December 22nd, 2008
