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Case Study: Beneteau Cyclades 43.3

SV 'Luna di Miele' - Electrical Upgrade Project

by Kevin Monahan - June 2022

6x170W SunPower flexible solar panels (installed 2021)

ElectroMaax AT3 System

Victron Energy MPPT controllers

I am writing this to provide the reader with information on how we upgraded many of the electrical components in our 2005 Beneteau Cyclades 43.3. We are not endorsed or sponsored by any of the equipment providers noted below. My goal is to provide the reader with information only. Take from this what you want and I am not writing this to start a debate or to obtain equipment or other favor from anyone. My only goal is hoping this will help you determine what would be best for you and your sailing (or motoring) adventures.

We purchased Luna in 2019 in Seattle and immediately knew we were going to be sailing her all the time. Jump forward 2 years and we are living on her full time. Once we had her, we realized she was not set up electrically for what we wanted to be able to do. We started looking at what could be done. Luna had the original Yanmar 4JH4E engine (less than 1,800 hours when we purchased her) with the original alternator. The DC electrical system is 12 volt. There were two West Marine lead acid 4D batteries (200 Ah total capacity) for the house loads and the standard size lead acid West Marine start battery for the engine. Ofcourse there was a shore power connection with the associated charger that would charge both sets of batteries. When not at the dock the engine would have to be run every day for several hours to charge the batteries. The alternator was rated at 80 amps but as most know those original alternators could only output about 60 amps, on a good day. That was not going to work for us!

The first upgrade to the system was installing solar. We did the research and spoke to Lyall at Sun Powered Yachts. He and I discussed our needs and luckily he was going to be at the Seattle Boat Show a few weeks later. We met there to discuss our needs and look at some of the equipment. We decided to go with 4 of the SunPower flexible 170 watt panels set up as two sets. There are two panels per controller and the controllers are the Victron Energy MPPT series. This provides redundancy and allows us to maximize output from the solar when there is some shading.

We got the entire setup from Lyall and it shipped right away. Everything we needed was included. We would have installed it ourselves, but we were not living near Luna at that time and decided to have a local marine contractor install the system. The install was done but we found several mistakes and had to make several changes and improvements (repairs) myself. The solar performed well, even in the Seattle area. In 2020 we sailed Luna out of the Straits of Juan de Fuca, made the big left and down the Pacific coast to her new home in Southern California. It was a grueling trip but that is another story!

In 40+ knot winds we discovered another installation issue when the solar blew off the top of the Bimini. The installer had used “strong” magnets to attach the panels to avoid having to remove the Bimini top and sew fasteners to it. That sounded good at the time but it did not work. The magnets were supposedly marine grade but started to quickly rust and crack. We knew we needed a better mounting solution (more on that later). After a few months in the sun and spending much more time on the hook, we wanted to add some other comforts such as a freezer, inverter and a dive compressor. That began the search for how to greatly improve the electrical capabilities.

We knew we would need much more battery storage capacity and a way to charge the larger battery bank. There is no room to install a permanent generator in Luna. We already had a portable generator and that works as a good backup. We came to the conclusion we would need Lithium batteries to get the capacity and be able to fit them in the limited space. We contacted several battery manufacturers and suppliers and they all had reputable products, but at that time many of them were not providing complete systems, only the batteries and some components, and they were not much help in trying to piece the system together.

We also needed a way to provide high output charging and electric generation. There was a lot of time spent on the internet, asking questions to other boat owners both on‐line and locally, talking to marine electricians, and weeding through so many opinions of what is good and what is not. We were surprised that the boat yards and marine electricians did not have much knowledge or experience with solar and lithium batteries or any idea on how to put a system together.

We do not recall where we found the information but we found ElectroMaax. I made the typical inquiry via their website expecting an email with some data sheets or other sales data. What I got was a call from John Stevens, the President of the company. We had a great discussion on what we wanted and what ElectroMaax could provide. The system would consists of the 250 AMP GenMaax Alternator (with the required hardware to mount on the engine), the control system and four 114 Ah LiFePO4 batteries. We made the purchase. Unfortunately, this was in the early Summer of 2020 and as you may recall logistics was a nightmare.

The equipment shipped quickly but arrived several weeks later at no fault of ElectroMaax. I checked all of the equipment and it all looked good. I made voltage checks on the batteries and they were all at 10.5 volts. I contacted ElectroMaax and was told that there was no problem with them being at that voltage until I could get them charged. I did a mockup of all of the connections using the diagrams in the manuals. The manuals at that time needed a little work and I provided some feedback to ElectroMaax which was happily accepted.

The first item to be installed was the alternator. The pulley kit took about 15 minutes to install and fit perfectly. Installing the alternator took a little time. It also fit perfectly especially with the new adjustable bracket. Ofcourse there was the typical boat gymnastics to be at the front of the engine and at the side at the same time and that is not possible when the engine is under the companion way stairs. The external rectifier is mounted on the bulkhead above the alternator along with the Field Control Module. Next was installation of the batteries and the other controllers.

All went well and the four LiFePO4 batteries fit in the same space as the two original 4D batteries. We were not replacing the engine start battery. It was all connected and we were all set, or so we thought. The batteries would appear they were charging but would drop below 11 volts as soon as charging was not available (either it was dark and no solar, we turned off the shore power charger, or the engine was not running). I contacted ElectroMaax and we started troubleshooting. We made sure I had all of the wiring correct and it was. Next came checking the batteries and that was the problem. I removed them and reinstalled the 4D batteries. We made arrangements to have the batteries shipped back to ElectroMaax (they covered the shipping cost and arranged to have them picked up). It took a couple of weeks, again, for the batteries to get back to them.

They did extensive testing and while we will never know what happened, more than likely they were damaged during shipping. It was Summer and the shipping company may have left the shipment out in the heat and it was almost 43'C/110'F when they were delivered. But, we will never know. John and I had several calls from the time prior to the batteries being shipped back to ElectroMaax and after the testing had been completed. All of the calls were good. ElectroMaax offered to replace the 4 batteries under warranty. That was perfectly acceptable and what we expected. John then offered another option.

They had just come out with the new AT3 control system and they have a new model battery that had a higher capacity. This was not a bait and switch or anything like that as ElectroMaax was ready to ship the warranty replacement batteries. We made the decision to go with the new system as it offered some added benefits: More capacity; The ability to connect to it via Wi‐Fi and Bluetooth; NMEA2000 connectivity.

We were also in the process of replacing the 15 year old electronics on Luna and the NMEA2000 connection offered better monitoring of the electrical system. We also decided to add one more battery since the new model batteries were slightly smaller in physical size but also were slightly larger in capacity. We could fit the five new model batteries in the same space as the previous four LiFePO4 batteries. We paid the slightly higher cost of the new model batteries and the additional battery. ElectroMaax provided the new AT3 system at no cost to us as a replacement for the original system (which they still offer).

The GenMaax alternator did not need to be changed. When the new batteries and controls arrived, and yes it took several months due to logistics in 2020 and 2021, we did the same checks on the batteries and did the wiring mock-up. All checked out perfectly. The diagrams in the manuals were much better. The installation went well. All of the cables for the controls, along with temperature and other sensors were included. We had to make the cables to connect the batteries but that has to be a custom fit and cannot be provided by ElectroMaax. The system was installed and fully operational.

A lot of testing was conducted with the batteries at full charge, low charge and everything in between. We ran the engine and alternator with a heavy load on the system and were able to get the output of the alternator up to 150 amps. We were trying for higher output but ran out of loads to put on the system. We still need to test it with the dive compressor. Two other items we added at the same time were a new shore power charger and a DC to DC isolated charger to charge the start battery.

Around the same time as we were waiting for the new batteries and control system to ship, ElectroMaax became a Victron dealer. We spoke with ElectroMaax to determine the best models for each of these for the system and ordered those items as well. Their prices for the Victron equipment were the same or better than we could find elsewhere. These were installed at the same time as the batteries and controls. The DC to DC charger for the start battery is connected to allow all forms of charging to keep the start battery charged and the start battery cannot power the house loads.

We had already installed an inverter for large AC loads and were able to connect it when we installed the system. It has a remote on/off switch and we turn it on only when needed. It is great to be able to run the electric kettle, hair straightener, hot air gun, pretty much whatever we need. We installed two small inverters to provide power for small AC loads and for the Starlink internet so we do not have to power the large inverter for those small AC loads we use all the time.

Soon after the system was installed were looking at our cockpit cover (Bimini) and decided it need to be replaced. The “Admiral” performed the daunting task of making the new one. Yes, we purchased a Sailrite LSZ‐1 (and later added the Worker Bee). That paid for itself just doing this one project and she has now done so many more projects with it. She included new mounts for the solar and rather than settle for the 680 Watts of solar we had, we went back to Sun Powered Yachts and purchased another identical set and added that on the Bimini as well for a total potential solar output of 1,020 Watts. The new mounting hardware uses LOXX fasteners. We have seen winds up to 70 knots and they do not budge. Do we ever get to 1,020W…not yet, but we have seen over 850 Watts.

Fast forward to now, June 2022 – the system has been in full operation almost a year. Even when we are at the dock, we do not connect to shore power because we do not need it (and there is a “hot boat” somewhere on the dock and we burn through anodes despite having a galvanic isolator – other boats are having the same issue). We use about 15% of the batteries from the time the solar stops charging in the evening until it comes back on in the morning. We are conservative on power consumption but we do not limit ourselves. Of course, we keep a close watch on everything. The solar system will power everything on Luna and charge the batteries.

On bright sunny days the batteries will be full again in about 4‐5 hours and then into absorption and float. A couple of weeks ago it was completely overcast and grey for nine continuous days. The solar was doing its best but could not generate the power needed to fully charge the batteries but did provide some power. On day 7 we were down to 25%. We had purposely decided to see how long we could go without charging with the engine or shore power, only the small amount of solar charging. We decided to run the engine and charge up. We ran the engine at 1,000 RPM and were sending 100‐120 amps into the batteries. We left the engine running for a few hours and the batteries were back to 75%. That was good enough (especially with the price of diesel – shore power would have been cheaper).

Two days later the sun came out and we were back on full solar. It took about two days to get the batteries all the way back to full. Just in case you check the specs and charts on the ElectroMaax site for the GenMaax 250 amp alternator and see that it states it should provide more output than 120 amps at 1,000 RPM, please remember that the output will vary depending on what the system requires at that time. Even the solar will back down once the load requirement is lower. That is how it should work.

The battery and other component temperatures barely increased above ambient while charging at the high rate. I could have pushed the RPM higher but there is the engine noise to consider. The entire system is working great and as expected. The NMEA2000 connection on the System Control Module allows us to see data for the batteries and alternator on our Garmin chart plotter. Now we can check and monitor from the cockpit. The first picture below is the voltage and amperage from the GenMaax at about 900 RPM. The batteries were at 71%. The second is a few minutes later and you can see the alternator and an output of 40 amps and there were 42 amps going into the batteries. The Solar was providing the other 2 amps and the additional 10‐15 amps for what was running on Luna – yes it all goes onto the system and who knows actually how it flows…but you get the picture.

I also added a Raspberry Pi (RP) with an NMEA2000 hat from Copperhill Technologies. We use that as one of the backups for the navigation system and it displays all of the NMEA2000 data. The Victron solar controllers connect via USB to the RP to provide the data. I am working to bring that data on to the NMEA2000 system to be able to monitor the solar from the Garmin chart plotter. I created custom screens that provide us all of the data from the various sensors and of course the entire electrical system including all of the charging, system load and battery data.

Yes there are fancier ways to display the data, like Grafana, but this is simple and provides what we need. The first picture below is most of the electrical system. The second is the overall screen we use the most for the important data on Luna. The third is the solar. You might like some of the companies we utilized, and you may not. We are not endorsing any of them. We are not seeking any sponsorship. We are not looking to get free “stuff”.

I know the big question is, what was the cost. The Admiral gave me a budget of $10,000 USD. I went a little over and came out around $12,000 USD. That was in 2020 and 2021. As you all know prices are much higher now. To get your price(s) you will have to contact the companies you will be using. We did all of the installation including making the cables that were not supplied. Installing it ourselves saved us thousands of dollars and we know everything about the system.

We were able to make the large electrical cables using the tools at our local chandlery. I do want to emphasize to use only marine grade components. Also, I went oversized on all of the electrical cables. Yes, it does cost more but then I do not have to worry about any voltage loss or overheating of the cables. Always consult a marine electrician, especially if you are not familiar with any aspects of the installation.

Our hope is this might help someone figure out what they need and how to do it. Enjoy your time on the water and be safe!!

Kevin Monahan

Update September 2023: Kevin added an arch and 2x415W-R Maxeon fixed frame solar panels

Hi Lyall,

Thought I would let you know that the Maxeon 415 panels work great!   How great?   Yesterday they actually had maximum output above 415 watts.   The below are screenshots from the controllers and each panel is on its own controller.  If you look at the Pmax for yesterday for each one was 439W and the other 445W!

With the 1850 watts we have now, we don’t need to plug in when we are at the dock and even with cloudy days we are good!


Thanks again for the great product and service.

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