Correcting the list – LiFePO4 power system design

In the 3 years I have owned Grace, I have completed a lot of projects, one of the biggest being updating her power infrastructure. In the last 2 years, a problem has surfaced that I needed to correct before the next season – a deep list to starboard. In addition, my original design had some things I wanted to improve upon.

The List

Every boat at some point lists one way or another depending on people, equipment and design. The 2000-era Benetau line is no exception, and in fact I found out from the various owners groups online that my model is prone to a significant starboard list even with the boat totally empty. This seems like an unfortunate choice in Beneteau’s design, as the starboard lazarette in the cockpit is the only major storage area outside, and the single biggest storage area on the boat. You could easily fit four people in the space (not that we store people) and we routinely dump anything and everything in here.

For normal trips, we will have one or two 5 gallon diesel cans (full), two batteries for the Torqeedo outboard, spare steering gear, tools, safety gear, a bucket full of outdoor junk, folding chairs, and much more.

So after cramming this full of stuff, the list increases even more. On a relatively flat bottom stern boat, this creates some problems if it gets too high. I am also ultra-sensitive to any list because of my inner ear. Surprisingly, I get seasick very easily, and often have to wear a special electrical watch to counteract the effects. I have the same problem (more intense/worse) on airplanes, and have to do the same thing. Any sort of list heightens this when I am down below, even at the dock – I can tell instantly when I go below that something isn’t right. My body tries to compensate when I move around the cabin, and I’m constantly fighting it.

During the power upgrade from a couple of years ago, I replaced one battery in the lazarette with two slightly larger ones – 110 amp hour Firefly batteries. A third was in the engine room in the bay originally set aside for a starting battery. My boat didn’t really have room for batteries of any significant capacity anywhere else, and after some tests, it seemed like the list was manageable.

Grace also had higher power requirements than when we bought her. I wanted an inverter to deal with smaller loads on the AC side while away from the dock, and we had a lot of computing and network stuff that I had started adding. This necessitated a larger house bank. At the time, combining house and start, which I had done on Jammy, was an OK trade off for me if I got more overall amperage hours.

Many people in forums and elsewhere disagreed with the amount of amp hours I needed on Grace, saying things like “inverters are only worthwhile on a sailboat as an anchor” or “you live with the amperage hours you’re given” or even things like “that’s why I only sail her overnight off dock power for 1 night at a time”. These are great opinions for your boat, and I am happy to let you have your own opinion. However, that is not the only solution. Inverters come standard on even smaller sailboats nowadays. Many of them are super light, and double as a high amperage battery charger. And if you let your boat dictate not only where you can sail, but your comfort and joy while you are doing that, that is your choice. I would rather be able to sail longer, enjoy myself more, and that is why I am willing to work harder and design something different, and potentially give something up.

Everything worked well on Grace, but the list was starting to bother me. In several trips last year, it was so pronounced at times that I was worried about stability in bad conditions. Crossing the Strait of Juan de Fuca with 4-6′ rolling waves, and in other situations, the boat didn’t feel as stable as I would like.

Grace arriving in Friday Harbor with a pronounced list, photo by Steve Roberts.

My home marina even called me and asked if I had a problem on board one day, or if it was a permanent list – they note these things in case they see a boat change. For them to notice was significant. After seeing some pictures of her as we were motoring in flat calm, I knew I had to do something – the list was really too much.

The Improvements

My original power system design eliminated a dedicated starting battery, which I had done on my previous boat Jammy as well. While this had worked well for the last few years, I was always worried about drawing the house battery bank (the only bank) down too low, and having to use my Noco jump starter to get things going. I wanted to see if I could add a small start battery back to the design to prevent this from being an issue. Also, having a start battery solves a ton of issues with charging a LiFePO4 bank via an alternator, so it almost could be a design requirement.

I have been wanting to add solar panels to my bimini to help with power usage while away from the dock. I had read a post from Patrick on S/V Violet Hour about their setup, and it had inspired me to consider doing something very similar on Grace. I wasn’t excited by any of the solar controller options MasterVolt had available, especially since they had only a few options that were MPPT and none that could be networked. Being that Grace used mostly MasterVolt, that brought other vendors or a different design to mind.

MasterVolt had also really not impressed me with their networking and monitoring solutions. They came out with a new version of the EasyView panel recently, which I had been testing, but it was still very rudimentary. Their ability to place this information on a NMEA 2000 network was also frustratingly complex. There was no remote access for this information other than piping it through SignalK or another tool. I wanted to see if other vendors had better solutions for this.


So after a lot of thinking, design, and planning throughout the late fall and winter months, I decided to take the plunge into a lighter weight power system with some improvements. All indications pointed towards LiFePO4 batteries as being the only option that could get me the weight reduction, but at both a cost in terms of money and system complexity.

One thing I did not want to deal with is a home-build of LiFePO4 batteries. It seems you can save considerable amounts of money by doing it this way, but the extra work required to maintain and manage the individual cells, plus the potential for problems, seems like something I didn’t want to take on in addition to the complexity that I knew would be present anyhow.

After reviewing around 10 different vendors, their capabilities and limitations, cost, and implementation details, I found that there really is only one vendor out there that met my requirements – Victron.

One of the things to consider with a LiFePO4 setup is the amount of safeties and controls you need to put in place to protect the batteries and other systems. This plus the data I wanted on the system itself in terms of its health meant that I did not want to mix vendors for various parts. This type of battery and system is still very new to the marine world, and combining different vendors and types of equipment would definitely lead to finger pointing when there were problems, and problems no one has seen yet.

NeverDie BMS – image courtesy of

As an example, I really liked Lithionics Batteries and their Never Die BMS, but if I used them with my existing MasterVolt inverter/charger, I would have to carefully program it, and then put in monitoring devices in several new areas to ensure that I did not overcharge them, even with the Never Die BMS in place. Some of those devices would be standalone, and require more programming individually, and if I got it wrong…

Similarly, if I chose to use a Victron inverter/charger, but a different brand of batteries, I would be responsible for integrating the over and under charge wiring and controls into the Victron to ensure no damage was done. All vendors seem to provide ways of doing this through relays and other means, but the conditions of when those items stop/start and fully integrating them correctly would require significant time to program. In addition, if one of those technologies does not work, you could damage your LiFePO4 battery or something worse.

The biggest reason for choosing one vendor is the fact that they tested the components I would be using all connected together, and have guidance on almost all of the configuration. Given LiFePO4 batteries are expensive, and the market is still in adoption phase, I felt that this would reduce my risk of having any problems.

After a lot of investigation, I decided on a fully integrated Victron system for my design.


Figuring out the design of the system took a considerable amount of time. While Victron has a bunch of example diagrams on their website and in their documentation, many of them are generic and don’t get into some of the control details. What I did know was my criteria:

  • LiFePO4 battery technology – self balancing with safeties/controls
  • 300 amp hours of house capacity
  • Non LiFePO4 start battery
  • Inverter / charger with at least 2000W of inverter capacity
  • Single control point within inverter / charger for all inbound AC power from dock
  • Support for charging via solar
  • Support for charging via alternator
  • Monitoring both on-boat and remote

Four battery locations – under the settee, under the master bed, master bedroom cabinet, displacing the air conditioner

One of the single biggest deciding factors in the design was the size of the battery or batteries. Even though I was 99% sure I would choose Victron based on their integration and completeness, I was struggling finding a place for the batteries that didn’t just continue to perpetuate a list. I considered using Lithionics Batteries as they had tons of different sizes and amp hour configurations that I might be able to shoehorn in somewhere.

I looked everywhere throughout the boat for a good location for the battery. One great area was where the air conditioner is mounted, which if removed, could have fit the 300 amp hour Victron LiFePO4 battery, just barely. I still would have had to modify the drawer above, along with the dry goods storage area, and of course, lose the air conditioner. I discussed this with the crew, and they sounded on the edge of mutiny if I removed the air conditioner, so that idea was tabled.

The settee area was OK, but I would have had to split the battery up into smaller 90 amp hour versions, and put multiples in there, which would have required a lot more cabling and fusing. Same with under the master bunk.

The best location turned out to be the storage cabinet in the master stateroom, which conveniently is located on the port side of the boat. Hopefully having the battery there would negate the list! It would require reinforcement and other modifications, but I was OK with losing storage here if it meant a better balanced boat with lots of power.

The other consideration in all of these locations was distance from the inverter and distribution busses. I tried locations near the cabinet inside the master stateroom for the inverter, but none of them really were optimal other than cable length to the batteries. Regardless of which inverter I chose, it would stick out into an area where I already bump my head too many times, and it would be noisy and generate heat where I sleep. Ultimately the best location for the inverter/charger was the lazarette, where it had been before.

To start figuring out my design, I jumped into Victron’s manuals, whitepapers, and also Victron Live, their living documentation with comments. I also found forum posts and other people’s designs, mostly for RVs and vans, and reviewed as much of their implementations as possible. Most of what was documented covered the high points such as the inverter, battery, charging sources, and the like, but didn’t cover specific areas like a battery management system and the control pieces around it.

To be fair, Victron has some of the most complete manuals, diagrams, white papers, and examples of anyone out there. Having had MasterVolt on my previous boat Jammy for years, and moving pieces of it over to Grace, I was very surprised at how much more information was available from Victron.

Still, even with all of this, I was missing some key pieces of information, mainly around how the battery management system worked, and did I have all of the right pieces and parts. Victron directed me to Peter Kennedy Yacht Services, a big distributor of Victron in the US. Peter himself answered all of my crazy questions and emails and reviewed my proposed diagram and design. Peter also setup a demo lithium battery system that was extremely helpful in designing mine.

I ended up with the following Victron components:

I went through many, many revisions of how things were going to connect, where they were going to be installed, and configuration options. One of the most valuable tools when planning things on the boat, which I’ve cited before, is OmniGraffle. For Windows users, it is similar to Visio, but with a lot better user experience and easier to use. It was extremely helpful in designing this system as I could vary how things were cross connected and easily see issues with the design.

The whole system came together very well, and is represented above. I didn’t put every last connection on the diagram, but the important control and power pieces are there. Lets go through the design:

House Battery

The central part of this is the 300ah 12v LiFePO4 Victron Smart battery. This simplifies fusing and wiring, but it does mean it is a single monolithic piece. This means that if this one battery dies somehow, the whole house system is unavailable. I’m OK with that since the likelihood of that should be pretty low given the amount of instrumentation and control is around it. I also looked at two smaller amp hour batteries, but overall they would have required quite a bit more room, and more wiring and complexity. For my needs, this seemed to be the best solution.

I really liked how Victron’s Battery Management system would connect directly to the battery, and that you can check on individual cells via an easy to use Bluetooth app on your phone.

Start Battery

The start battery is a LifeLine AGM starting battery I had from another random project. It is more than enough for my 20HP Yanmar engine.


The VE.Bus BMS is the main part of the control system. It connects directly to the LiFePO4 battery and monitors its health constantly. It is responsible for dropping loads if the battery is too depleted, or stopping charge sources if the battery is full. The unit has two RJ45 ports – one connects to the inverter/charger and allows it to control it directly, while the other connects to the Digital Multi Control GX panel which I cover below. In addition, there is a set of power connectors, and two connectors for the low voltage and high voltage disconnect signals going out to the control devices/relays.

The second part of the control system is the BMV-712 battery monitor. This piece is critical with a LiFePO4 battery to ensure you are always aware of the amount of amp hours you have consumed. It consists of a shunt at the house battery, a gauge in the main panel, and a connection between it and the next part of the control system – the Color Control GX display. I also wanted it to monitor the voltage of my start battery. It has a ton of configuration options, and is one of the best battery gauges I have ever seen. You can also interact with it via Bluetooth which is helpful to configure it, as well as check on status of your batteries via your phone.

The most visible part of the control system is the Color Control GX. This is a beautiful panel that connects everything together in the Victron world. It has bus ports for VE.Direct, VE.Bus, VE.Can and more. You can configure each of the connected devices (to a certain level), setup alarms and monitoring pages, and set parameters of your Victron “system”, allowing for different behaviors depending on the pieces you have connected together.

One of the best parts about the CCGX is its ability to send your data out an internet connection to the Victron portal, or VRM. This allows you to see pretty much all of your data online from a web browser, or from one of Victron’s Android or iOS apps on your phone. You can even set things up to allow for remote control of the Color Control GX via the website, which is useful if you need to see more details or make a change remotely.

The Color Control GX will be the flagship centerpiece of the system, allowing for quick access to the health of the whole power system.

An additional part of the control system is the Digital Multi Control GX panel, which is essentially a carbon copy of the panel on the front of the inverter/charger. This piece is required, and is sort of a hack in my opinion, because if you want to change the input amperage available via AC power, you need this panel. Without this, you cannot change it with the current Victron setup – something that clearly sounds like a hold over from some of the different busses in use. Still, it is nice to have a panel that shows the inverter/charger status remotely, so I’m not complaining. In fact, I use it all the time to turn the inverter/charger off when we’re ready to leave the dock and I don’t want inverting to occur. This directly connects to the VE.Bus BMS.

The final part of the control system is the sometimes overlooked VE.Bus Mains Detector that sits at the inverter/charger, and is connected to the VE.Bus network and VE.Bus BMS. This device allows the VE.Bus BMS to “wake up” the inverter/charger in the event that you completely deplete the LiFePO4 battery and it shuts everything off for safety. Once you reconnect to AC power, the inverter will still be commanded off by the VE.Bus BMS, but this device allows it to turn it back on once it senses AC power.

One thing I will mention is that the different types of busses available for Victron products is a source of a lot of confusion. You have at least three different similar types of busses – VE.Bus, VE.Direct, VE.Can – and some products support varying versions of some of these. The only device that has all of them is the Color Control GX, which is good since that is the central piece. However, it is clear that some of these products were built separately, and Victron is trying to unify them all. The result is different size and types of cables, confusion over which ones are necessary, and a complex setup in some cases. Victron is apparently moving towards VE.Bus for most things, with the Color Control GX using VE.Can to dump information onto a NMEA 2000 network, and potentially longer term improvements.


Charging can happen one of three ways – via the Inverter/Charger when connected to AC dock power, from the engine alternator, and from the solar panels.

The MultiPlus 12-3000-120 Inverter/Charger can charge at 120AMPS while on AC power. It is connected to the VE.Bus BMS and controlled by it depending on the needed charge. It is a very effective and high power charger. Since Victron makes the battery and inverter/charger, there are only a handful of settings required to get it setup correctly, which is a nice change from other products I reviewed.

The engine alternator is a Electromaax Cruiser High Output model capable of 120AMPS. It is paired with an E-MAXX Pro regulator and display panel, and the engine belt system has been upgraded with their serpentine kit to provide for dust free charging, and allow for the 120AMP output. I will be delving into this product a bit more in a separate article. The start battery can be connected to the LiFePO4 battery during charging using the Cyrix relay. It watches for charge level voltages on the start battery terminal, and reads a voltage signal from the VE.Bus BMS, and will connect the two batteries together if criteria are met, and charging is appropriate.

The solar panels are two 100W flexible panels mounted on my bimini, connected to the BlueSolar MPPT 75/15 solar controller. The solar controller is connected to the Color Control GX via VE.Direct, but it cannot command it off – another strange compatibility limitation, likely due to the bus type. As a result, I have a BatteryProtect 65 between the charging leads from the MPPT controller and the LiFePO4 bus. This allows the VE.Bus BMS to completely disconnect the solar panels in the event that the battery is being overcharged. The controller also has Bluetooth, and can be configured using the Victron app. You can also see a wealth of information on solar performance, charging, and historical data via Bluetooth.


There are three main DC power load sources – the Inverter inverting DC power to AC outlets throughout the boat, the main DC panel and loads, and the secondary loads including the Wallas heater, etc.

The inverter loads are controlled by the inverter itself, along with the VE.Bus BMS.

The main DC panel and loads can be disconnected in the event of a low voltage condition by a 100AMP BatteryProtect that is connected to the VE.Bus BMS.

The secondary loads can be disconnected in the same way, but with a slightly smaller 65AMP BatteryProtect.

Charge & Load Limiting

The control parts of the system are responsible for turning off loads or charging in the event of an issue. Those control systems include the BatteryProtects for the solar charger, DC loads, and secondary loads, as well as the Cyrix combiner for the start/alternator charging source. These devices sole purpose is to monitor voltage (in the case of the Cyrix) and disconnect their device if the VE.Bus BMS commands it to.

They are critical to ensuring the LiFePO4 battery is not overcharged or discharged too much. This is part of the complexity in a LiFePO4 system that is required, but I think this is something that even non-LiFePO4 battery bank setups should consider. I have worked on tons of folks’ battery systems, and many times they have drastically overcharged batteries with badly regulated alternators, or incorrectly configured chargers. People also discharge their batteries to frightening levels without understanding the implications – once voltage falls to a low enough level that stuff stops working, they consider it empty, which could potentially be damaging their batteries.

The Cyrix and BatteryProtect products can be configured to operate in standalone modes and monitor specific voltages, and take action when things fall below/above particular thresholds. I think it could be interesting to look into using these with traditional banks as well.

Inverting & AC Power Control

Grace’s AC items include two different 15AMP circuits for AC outlets, a water heater, and an air conditioner. The latter two devices are way too high to run away from the dock, and were classified to be used when dock AC power was available. One of my requirements was to have inverter power while away from the dock just for AC outlets throughout the boat, and the MultiPlus Inverter/Charger is perfectly suited for this.

The plan was to run AC power from the dock inlet plug to an ELCI breaker (new) and then into the MutiPlus Inverter/Charger. The MultiPlus model I chose has two AC outputs, one for inverted devices, and one only available when standard AC dock power is on. This allows a centrally controlling point for all AC power.

There are a couple of benefits in doing this. Most importantly, I can use the Digital Multi Control panel at the nav table and a Victron feature called PowerControl to dial in a particular AC dock amperage so I don’t trip the dock box circuit breaker. I had something similar with my MasterVolt setup, but it was never quite that easy to set. This configuration is perfect, as when we pull up to the dock, the air conditioner and water heater can kick on and suck a ton of AC power, and the charger gets whatever is leftover to charge the batteries, and we’re not tripping breakers.

In addition, if there is too much load on the AC power side, the inverter can source power from the batteries to augment the AC power available if you so choose. At the dock that would definitely be nice if needed. This feature is called PowerAssist.

The overall inverter power was slightly higher than I needed at 3000W, but this was the only inverter that (a) fit where I wanted to put it, and (b) had the multi AC links, load sharing and power control features all in one.

Careful Wiring for BMS and BMV

The VE.Bus BMS and BMV-712 battery monitor need to be wired in a way that they never get turned off even when the LiFePO4 battery reaches critically low levels. Both of them are critical to ensure you know the state of the LiFePO4 battery, and the BMS can see if charge is applied and command other things back on. If it gets shut down when voltage is low, nothing will come back on and you’ll be in a bit of a catch 22. However, if you intend on leaving the battery unattended for long periods of time and it won’t be powering any load, put everything into storage mode, disconnect the BMS and BMV. Even leaving the BMV and BMS connected in a deep discharge situation can be bad, as they will continue to drain the battery, which is death for LiFePO4 after a certain level.

This is sort of a contradiction if you think about it – they should always be connected, but in the event that you are in a bad situation with super low capacity left, they themselves could damage the battery over a long while, drawing a small amount of power.

For my design, I have a panel with fuses wired directly off the battery terminals so that even if I throw the battery switch, they aren’t disconnected. I have so much instrumentation and monitoring that I would always know when the battery was being severely discharged, and not be able to get to the boat within that same day and completely disable things if there was a critical long term outage of AC power. If I were leaving things for a long period of time, I would turn everything off, and pull the fuses for the BMV and BMS.


Once I was happy with the design, I placed my order through PKYS for all of the Victron components. I waited to order wire and other bits until everything came, and I could validate my placement and design.

Read about my installation and use of this system!

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38 thoughts on “Correcting the list – LiFePO4 power system design”

  1. Thanks for an interesting article Steve.
    One only question – why did you keep the START battery AGM Lifeline and not switch to LiFePO4 for this use??

    • Erik,
      The main reason was that AGM batteries don’t require the instrumentation and cutoffs that LiFePO4 do. I wanted something very simple systems-wise that was responsible for starting the engine so that I always have a way to get the alternator going again and charge the house (LiFePO4) bank back up.

      Secondarily, I already had the battery, and it is a cranking AGM model which fit perfectly with the start profile with engines. I could have gone with an even smaller battery as I have seen others with my size sailboat engine do and saved even more space.

      • Thanks Steve – I understand your point.
        Was wondering if the AGM batteries has a higher power for cranking the engine than what could be expected from a similar Ah LiFePO4 unit?

        • I did a lot of research here, and most of it showed that cranking specific batteries, like the Lifeline AGM one I am using, are better suited for short spikes of usage while starting. There was also differing opinions on whether that was even necessary given the size of my motor (20 HP Yanmar). This is definitely still an area where there are strong opinions one way or another. I did run across a decent amount of people who use LiFePO4 for starting and they seem to be happy with it as well.

        • LiFePO4, as a chemistry, offers far superior cranking amps over AGM.

          However: AGM batteries don’t have nor need a BMS that can enable/disable charge/discharge. So there’s no additional components that high amperage cranking current has to pass through on AGM batteries. Adding the required shunts and contactors that make up a BMS to keep an LFP battery from being over charged/discharged adds a lot of cost, weight, and space. Especially if these components have to be sized to handle high current spikes.

          Most manufacturers of “pre built” LiFePO4 battery packs are aiming more at the “energy storage” market rather than the “engine starting” markets. These markets don’t have super high surge currents like engine cranking requires. So they save costs by using BMS equipment that can only handle a fraction of the “surge” amps that LiFePO4 is capable of producing.

          For example: The actual *cells* in a typical 50 Ah LFP battery can easily push out 1,000+ amps to crank a motor for several seconds. However that current has to first pass through the shunts and contactors inside the BMS and those components can usually only handle 20-80 amps in that size battery. In fact the BMS will disconnect the battery if it sees excessive current. This makes it so most off the shelf LiFePO4 batteries are not suitable for engine cranking.

          One of the only companies I know that make LFP batteries for engine cranking are EarthX. I have several of their batteries and they are great. Their largest battery is only 25 Ah and only weighs 7 lbs but can sustain 1,200 cranking amps of current for engine starting.

          • Hi Jeremy, would you mind sharing how did you manage to connect Orion Jr to the Victron Ecosystem? I’ve seen your questions on the official Victron website (comments are closed there now) asking about Multiplus’ assistants and the AUX port but getting literally no help at all, joke answers… Anyway, I was wondering whether you used the Assistants and AUX/T-Sense ports on the Multi OR maybe connected via CANbus?

          • Sure. It’s been a while and I went through a lot of iterations but it’s working great now. I started with the assistants using the AUX and T-Sense ports. I finally managed to get them to work as expected once I realized that my problem was there was no common ground between the Orion and the Victron. (Big DOH! on my part) You see I was powering the Orion BMS from the 12v system but the inverters were only connected to the 48v system, and I hadn’t grounded the 48v in order to reduce the chances of a 48v wire shorting to the chassis.

            Once I realized that the Orion wouldn’t be able to push or pull voltages to the Victron without a common ground to complete the circuit that really solved all of my issues. I just added a small jumper (With a small 5 amp fuse) between the negative post of my 48v battery and the chassis ground.

            Once I had that working I moved on to the CAN bus integration, which was super easy to do. So now I have the assistants as a “back up” in case CAN communication fails, but the primary control mechanism is now CAN bus. The CAN connection goes between the Orion BMS and the Victron CCGX. Then you simply configure the CCGX for ESS mode and it takes over controlling all of the chargers and inverters based on the voltages communicated by the BMS over CAN bus. It’s a really slick set up.


  2. Nice write up. Is the Alt regulator setup with AGM or LiFePO4 parameters? Just not sure how you run two different battery chemistries in parallel without being incorrect for one of them.

    • The alternator is actually set to LiFePO4 parameters for the charge voltages. This is pretty common with these mixed setups. The voltages are within the range of the Lifeline AGM so that works out, and the majority of the charging of course goes to the LiFePO4 except for the few minutes (or less) after starting the engine. Longer term, I may consider switching this one to a smaller LiFePO4 battery if the cost drops.

  3. “This piece is required, and is sort of a hack in my opinion, because if you want to change the input amperage available via AC power, you need this panel. Without this, you cannot change it with the current Victron setup – something that clearly sounds like a hold over from some of the different busses in use.”

    Uhm… I have been changing shore power limits on a CCGX for years without needing a separate panel. I am puzzled what about your system prevents the normal CCGX interface from working?

    – Chris

    • With the LiFePO4 BMS and the newer Multi inverter, the CCGX can’t control the shore side amperage amount. It was in Victron’s manual and I tried it before connecting things together. The setting in the CCGX remains blanked out. Maybe you have an older Multi or non LiFePO4 BMS?

  4. Steve I have just implemented a very similar all Victron setup to yours, my diagram is in the Facebook group. I feel that having a Lead Acid starter battery is a fairly important part of the design. It acts as a permanent connection for the alternator in case the LFP disconnects and for me it’s something I switch In when the boat is laid up and unattended as in this case I physically disconnect the LFP with a SOC of around 60%.
    I had a slightly different approach to the BMS in that I wired it direct from the LFP bus through a switch so in working use it is always live. My Venus GX and BMV are powered from the load disconnect terminal of the BMS so they switch on and of with it.
    It’s early days for me yet but I’ve found the biggest challenges with LFP are when permanently hooked up to shorepower and when leaving the boat unattended. When on shorepower I’ve only connect power to the Multiplus for about 90 mins a day.

    • Hi Tim,
      Thanks for the notes. I agree about the standard starter battery, and is why I have wired my system a similar way so that the alternator always has something to charge. I have never reached a state where the boat is laid up – I always have a DC load of some sort and will often times disconnect shore power and let solar top things off, letting things discharge as well.

      I have a functionally similar setup – BMS, BMV and GX are on a panel directly powered by the LFP bank, each with a fuse that can be removed if I wanted to shut everything down. I also have a master battery switch from the LFP bank going out to all loads of course.

      How are you only connecting shorepower for 90 minutes a day? Manually? Or have you figured out some way to program things to do this?

      • I only have the shorepower connected whist onboard. Right now the boat is on the hard in Trinidad and I’m in UK. The solar is floating the Lead Acid Battery. Switching off the BMS is really the equivalent of disconnecting the LFP but I sleep better knowing it’s physically disconnected, 2000 miles away!
        The idea was that I monitor the boat using Victron’s VRM whilst I’m over here but unfortunately the way I wired up my bullet WiFi device means that it got powered down when I shut down the boat. The Venus GX will buffer all the data on an SD card and upload it next time it’s connected; not that seeing a Lead Acid battery floating for 5 weeks will be very interesting.
        I’m looking forward to using the new system for real when we get back to full time cruising in October. Not quite sure how my wind generator will be with the new battery, I’ll have to experiment a bit.

  5. Hi Steve:

    Again, I’m starting or cloning another one of your projects! I have decided to replace my aging Freedom 1000 Inverter and Link 2000 monitor (both 32 years old and still working!) with Victron equipment. I have decided to keep the flooded batteries for now, but replace the Freedom with the Multiplus 12/3000/120 and the Link with BMV-712 Smart. I also bought the Digital Multi Control, however, I really wanted the CCGX and will probably add that in the future.

    The purpose of this post is two fold. Firstly, I’m wondering if the reason for the CCGX to blank out the setting to adjust the shore amperage amount was due to the Digital Multi Control being present in your system? I ask this because the Digital Multi Control has at least one maybe two analogue switches that could not be changed digitally? I have also seen a number of Youtube videos that show the CCGX controlling the shore side amperage (e.g. ). I ask this question, because I only have room for one monitor and I would really prefer the CCGX over the Digital Multi Control. Maybe you could test my theory by unplugging your DMC remote?

    Secondly, when I asked about purchasing the NMEA 2000 cabling for Victron, I received blank stares and quotes of $300+ per cable. Would you please share your experiences with this aspect of your installation?

    Thanks again, Steve, for sharing your project on Sailbits.

    • Hi Bryan,

      Sounds like a great project!

      In terms of the DMC and CCGX, I read in several spots in Victron manuals that the CCGX was not capable of controlling shore side power amperage if you have those components combined with a MultiPlus, AC restart monitor, and the VE.Bus BMS for LiFePO4 batteries. I believe the BMS is the chief reason for this being disabled, as it is supposed to be in control of more things. I seem to remember the Digital Multi Control also being required for the BMS for other reasons.

      I can unplug my DMC and see what happens.

      NMEA 2000 cables are quite confusing with Victron. You can get one for just about every module they make, and they do different things. They also can disable some functionality between Victron components on their proprietary busses as well, which was a surprise for me. I currently have the cable from the CCGX to my NMEA 2000 network only, which only allows the CCGX to listen to info from the bus, and not transmit. Victron has said they’re working on bi-directional communication for the CCGX.

      In the interim, I use Scott Bender’s wonderful SignalK library for Victron and a dedicated SignalK server. It connects to the CCGX over Ethernet and grabs a ton of info, putting it all on the NMEA 2000 bus.

      Depending on what you want on your bus, you could get the NMEA cable for the BMV and have your current SOC, charge/discharge rate, voltage, etc. on the bus very easily. Same with the MultiPlus, but it can disable some functionality when cabled that way (frustrating).

  6. Perhaps there used to be a limitation but I have a very similar set up and I can absolutely control the shore power current limit from the CCGX.

    • With the LiFePO4 BMS that was required in my system, it disabled the ability to change shore power without the add on panel. It was called out in the manual for the BMS, but perhaps they have changed that in newer software versions.

      To be clear, it had to do with the specific combination of the MultiPlus, BMV, LiFePO4 BMS and CCGX. Configs without the BMS work just fine.

      • I find that really surprising. I have the same set up, only difference is I have a non-Victron BMS (Orion Jr) as I built my LiFePO4 pack myself. However it integrates with the CCGX pretty much the same way as the Victron BMS does so I don’t really understand why the shore current limit would work with a non-Victron brand BMS connected to the CCGX, but not with a Victron brand BMS connected to the CCGX. Shouldn’t the Victron branded stuff integrate *better*?

        • You would think they would, but this was directly out of their manual. Victron’s BMS integrates using their proprietary busses, so I doubt a 3rd party BMS would work quite the same way. The main reason I had their BMS was because I had their batteries, and you have to use their BMS for those…

          • Oh, I see why now. Their BMS uses VE.Bus instead of CAN Bus. I find that surprising given the CCGX offers out of the box support for a wide range of BMS control over CAN Bus, and a lot of Victron equipment uses CAN Bus now instead of VE.Bus.

            All of the non-Victron BMS units integrate over NMEA2000 (CAN Bus) which as far as I can tell, provide the same capabilities without the need for a 2nd control panel. It’s kind of ironic that Victron charges a hefty premium to use their batteries and then make you buy more control panel equipment on top of it.

          • Correct. It is one of the reasons on my new boat, I will not be using Victron batteries, BMS, or BatteryProtect devices. It seems like a lot of this tech on their end grew organically – case in point the three different bus types involved in this system (at least!). They are working to make everything NMEA 2000 / CAN Bus compatible, and deprecate the other busses.

            I don’t have the CCGX right now (on the old boat) but the last software version still did not even allow you to see data that the CCGX was collecting from all of the Victron devices on the NMEA 2000 bus. The CCGX could read data from N2K, but it never sent anything out. I used SignalK and a plugin to connect to a modbus port and put it on N2K, but you shouldn’t have to….

  7. Using your setup as the basis of my own new Lithium installation. How do you program the voltage regulator on your alternator as is will be charging both AGM ( your starter bat) and your Lithium house bank?

    • If I remember correctly, I set the Balmar regulator I originally used, and the Electromaxx that was in this configuration to the LiFePO4 voltages and requirements. Since the start battery was very rarely ever discharged much, other than when starting the engine, the Cyrix relay was mostly charging the LiFePO4 side, and even though the voltages were different, they still matched in the range of what the AGM battery needed.

      • Thanks for the info. I would have guessed that if I had been forced to guess but it is good to know for sure when dealing with expensive things that can catch fire if abused.

        • Yeah, this is the downside to having a mixed chemistry set of batteries. The AGM/start battery was also the “relief valve” for the alternator, so that if the LiFePO4 bank decided to close the Cyrix relay due to overcharging or another condition, the alternator wasn’t left without a charge source, thereby potentially destroying the diode/charge circuitry in the alternator. The Cyrix relay was what really made this even better – it detected the voltage on both sides, and was an additional point where things could be controlled.

          I am upgrading my current boat to LiFePO4 in a month, and have been going back and forth on the design. For this one, I may choose to have the engine alternators (I have two engines) connected ONLY to the house bank, and have the regulator (likely Balmar 614’s) use a control wire connection to the BMS for the batteries, that way the BMS can control the alternator more gently. This means the alternators wouldn’t ever charge the starting batteries, and could be tuned just to LiFePO4 chemistry charging requirements. I could then put a small trickle charger between the house batteries and the start batteries that converts the voltage and charge rates to something AGM-style (which is what my start batteries are) so that they could be maintained when I am away from the dock.

  8. Steve, have you written more about the Electromaax system? I personally have the generation before the one they are selling now and have some strong views but wanted to get your take.

    • I have not written more about Electromaxx for a couple of reasons. First, I sold Grace last year and have a completely different system on my new boat. Second, I had a moderate amount of difficulties with the system, and was able to correct almost all of them after a lot of back and forth with the manufacturer. There were still a couple of items that I was never able to resolve, and ended up having to work around in different ways. However, the system did provide more charging amperage than any other system I tested on Grace, albeit with some quirks.

      This whole area of alternator control is one that I am surprised has not had more innovation for smaller sailboat motors. There are some new products out, one that I am testing now, and some that are looking very interesting that could help.

      Always interested in hearing other folks opinions on a system as well!

      • First, thank you for your extremely well put together articles. My office is right next to Peter Kennedy’s in Annapolis and I look forward to working with him on my LiFePO4 upgrade next year once my pockets have a bit more cash in them.

        With regards to Electromaax, I got on board with them about 5 years ago with the promise (as stated on their website and discussions with them) of an integrated system that would be able to be monitored via my onboard computer as well as over NMEA network. I had issues from the start including faulty temp sensors as well as a mis-wired alternator. I just learned that they are now in the BETA phase of a system that can be monitored through the onboard computer but not on NMEA network (5 years after them advertising it). I have had great technical help but had issues in other departments of the company. I love their ideas and motivation but I have found execution is well behind their vision. I also just went on their site and saw they are now advertising LiFePO4 batteries. I wish them well for they may now be producing a great product but based on my experience, I would never go with them again.

        • Thanks for the kind words! You’re lucky to live near Peter Kennedy – he’s a great resource for power systems, in particular Victron systems.

          One of the reasons I was attracted to Electromaxx was the same interconnectivity that was promised – NMEA 2000 links, computer data, etc. This is an area, as I mentioned above, that I am surprised around the lack of control and data we have over the power system, especially given it is one that ie used more than almost all of the other systems while underway and out on the water. The promise of NMEA 2000 was a big draw as well.

          I also had mis-wired alternator, and have heard from one other person that they had the same problem. This does not make me feel comfortable in terms of quality control.

          I agree on their ideas and motivation, but the execution leaves something to be desired. I noticed their website change as well, and I hope they are eventually able to deliver on their regulator promises. I would not recommend their equipment right now, and hopefully that could change if their execution improves over time.


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