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  1. Paul Wood says:

    Hi James & Jennifer, are you going to Tromso to visit the Artic Circle?

    • Yes, we are definitely going to Tromso but we have already crossed the Arctic Circle a couple of days back. We’re currently at 67 degrees 56 minutes north so 6 degrees closer to the pole than on any of our previous trips.

  2. Steven Coleman says:

    If you are interested in something to test “sockets” which I take to mean receptacles, this is a gives a little more information than a non contact tester. Although you do have to actually plug it in. This link is for one that will test GFIC’s however the one’s that don’t are only about 3 bucks less.

    • Yes, thanks Steve. I also have a pigtail that plugs into my international cord adapters to do this. I happen to use a UK device aimed at 240V but, otherwise, it’s the same as what you have referenced. Where there are issues I sometimes bring this tester our but I always use the non-contact tester as a quick verification that we actually have power at the shore power cord. The near instant results are appealing.

  3. Paul Wood says:

    Blimey, I’ve never seen a Twizy before, and I must say, it looks like a quad bike with enclosed body panels. Do they have a steering wheel or handle bars?

    Breath taking photography, too!

    • You are right Paul. A Twizy is essentially a quad bike with a steering wheel. But, I was kind of impressed with it. They are fairly inexpensive and, for many errands around town, the two hour charge would be more than adequate.

  4. Kim Nelson says:

    Long time reader of your blog. Thank’s for taking all of us along on your trip! Haven’t read any mentions but since you’ve crossed the Atlantic have you had any issues with bugs?

    • Bugs haven’t yet been much of a problem in Europe so far but it depends upon time of year, nearness to shore, weather and location. We expect we will see them in Norway at some point. We have seen some minor quantities of bugs in Scotland’s Outer Hebrides Islands but not much anywhere else.

      There was a similar thread on bugs in the comments section of the St. Katherines dock posting: The speculation was the overall bug density has decreased world-wide.

  5. Van Anderson says:

    James and Jennifer,

    Loving the pictures and descriptions about Norway. Thank you.

    Our new N68 is in the mold, finally, and we’re now deep into choices and decisions including really simple things such as the BBQ – electric or gas? We’ve decided to go with gas because we like the results much better than with electric. At least one other new 68 is going with an electric grill thinking that getting propane in the middle of the Pacific or Europe might be a challenge. You guys have been everywhere, what’s your experience with trying to find propane here and there? Or maybe you went with an electric grill, I can’t remember?

    Tracy says hello.


    • Van, it’s good to hear from you and Tracy. When we specified Dirona back in 2009 we went with propane stove top and BBQ because we didn’t want to have to start the generator every time we wanted to do something quick. We since put in a 240V inverter that will support any load in the house so we can do fast jobs on battery and, on longer jobs, we would start the generator. We can start the generator from any web connected device including mobile so starting the generator is pretty easy as well. In retrospect, we would go with electric on both the BBQ and Stove Top.

      The Advantage of gas is the control of heat and not having to start the generator. The big downsides are explosion risk and the difficulty of getting tanks filled in international locations. To mitigate the former, we have well designed storage areas that drain via through hulls overboard. To reduce the frequency of filling, we carry 4 20lb containers and only fill them every 2 years and sometimes longer. We filled in NZ which was technically not allowed but some operators are willing. We next filled in St Lucia. Then Again when we returned to the US. The last fill in the US was a big hassle because the person filling them had a real hard time getting the vent to operate correctly — not sure if that was an operator error or an aging valve assembly. Now that our Aluminum tanks are 10 years old, we will not be able to fill them in the US without re-inspecting and I suspect they might fail.

      I’ve been giving some thought to just replacing the aluminum tanks with steel tanks that we get in each country and just discard when used up. This would force us to get new adapters for each country but at least we would be buying a part that is normally available in that country. Another approach is to buy another set of aluminum tanks or go with the newer composite tanks (they were not looking safe enough at the time we last bought tanks 10 years back with recalls and explosion problems). Another more radical approach is to go electric — I suspect it’s just too much hassle to put in new 240VAC circuits for these new loads. I suspect we’ll move to the approach of buying local tanks and new hose connections every couple of years but we won’t likely face that for another year or so.

      We would recommend electric for your 68.

  6. Karl says:

    Hi J & J,
    Pretty simple questions if I may. I saw the lettering you were applying to your new tender and wonder what the type of material & source are. I have a hypalon tender that I need to re-mount a name on and lettering I’ve used in the past hasn’t held up very well.

    Also, in a few pictures I noticed you have aft-facing cameras mounted under the overhang of the cockpit. I’m assuming they’re weatherproof and wondering if they’re infrared/night viewing as well as type/source and if you’re happy with their performance.

    Very much enjoy seeing the pictures of your travels (and repairing Dirona in exotic places :). Continued safe travels.

    • The graphics are amazingly durable. These graphics appear to be an Avery printed film installed on 3M SCPS-2 Prespacing tape. Looking at the 3M page on the applications of the pre-spacing tape, they list the various film printing systems they support. The right approach is to find a sign company that prints Avery or 3M films. Here’s a link to the 3M SCPS-2 prespacing film that both 3M and Avery use:

      We have two generations of cameras on Dirona. There are some very old analog cameras that are used by the Furuno NN3DBB system. In this system we have a Flir forward looking Infrard Camera mounted on the forward edge of the lower RADAR support on the stack. In addition, we have an engine room camera and aft looking camera. Both of these are Raytheon bullet cameras which are surprisingly durable but certainly just generic cameras rebadged by Raytheon.

      The second generation of cameras are Reolink 4 megapixel cameras and we use a combination of dome and bullet cameras. So far we haven’t had any failures so these cameras appear to be very durable. We have a forward looking camera above the PH window, an aft looking camera on the stack, two side looking dome cameras on the stack, and two dome cameras in the ER, one looking forward and one looking aft. These cameras are remarkably good quality for the price and can be had on for only $60.


      We use a Synology DS416 central file server on Dirona

      The DS418 is the current version of this product:

      On the synology we use Surveillance Station which is a Synology product to acquire multi-channel video from IP cameras. It comes free with 2 licenses and you can get 4 more for $199:


      The Synology is wonderful, Surveillance Station is good value and works well, and the Reolink cameras are amazing price/performers.

  7. Kamal Rij says:

    Hi James,
    Long time follower, first time commentor. Great blog.
    What type of (US) bank account do you have. I see Jennifer and you withdrawing funds directly from ATMs in most of the countries you visit. This would be a great tip for US travelers who want to rely just on ATMs for local currently.


    • We’re actually using our Citibank Australia account which has no foreign transaction fees and works well just about everywhere. We also have a Citibank US account and it works in the same places and also doesn’t have a foreign transaction fee. These days most cards from large institutions seem to work all over the world. It’s rare when we find a bank machine that won’t accept our card and, when that happens, there is almost always another bank machine in the area that will.

  8. Jan Martin Hodne says:

    Hi, Ylvingen is a nice island just west of Brønøysund.

    ( googel translator)

    • Ylvingen looks beautiful on Google maps. We’ll keep it in mind for a visit on our way north or returning south later in the year. Thanks for pointing it out to us.

      • Karen says:

        May be too late for you now…but Tromso has the world’s most Northern botanic garden. It is lovely. The blue Himalayan poppies were out when we were there (June).

        • Hi Karen. I incorrectly figured in Northern Norway we had a shot at being somewhere you haven’t already visited :-). You and Gord do travel an amazing amount.

          Thanks for the tip on the most northern botanic garden.

  9. Asgeir J says:

    Velcome to Langøysundet. Nice boat! 🙂
    Right now You are stopped in «Ellingvaagen». (12. Mai 2018 kl. 18.40). Hope You have a nice stay in Norway! Remember our national-day 17. Mai. You must see it on-shore in Kristiansund og Trondheim. 🙂

    • Thanks for the hospitality. This looks like a beautiful stop and, wow, we have been loving Norway so far and we’re really only just getting started. It’s nice enough we might be able to eat outside this evening.

      • Asgeir J says:

        I dont know how much You know Norway, but I recomend to experience the 17th of May, Norway`s national day. It is more like a childrens day as they marching in the streets with Norwegian flag and singing national anthems. Highly recommended! 🙂

  10. Larry Martin says:


    Wanted to add my thanks to you and Jennifer to the legions of others for your willingness to share your hard earned knowledge. Electrical has been a knowledge weakness of mine and even as I build a land-based offgrid system I refer to your design work often. I have no need for frequency conversion and am putting off solar to the future so it’s amazing how much what you have done is instructive to me. Again, my thanks and appreciation.

  11. Rodney Sumner says:

    James and Jennifer
    Sadly my travels to the UK did not coincide with yours!
    If I read your personal tracks correctly it seems that you have been giving the new tender a good work out.
    As always thoroughly enjoy the blog – a must daily read!
    Just curious, with your hectic maintenance projects/schedule if you ever plugged that cable pipe in the aft Glendinning locker?

  12. Trond Saetre says:

    Welcome to Norway! I have been following you since you were in the Pacific, and I see you are heading to “my area” now. I live in Bergen and do my boating in the western and southern parts of Norway.
    On your way northbound, passing the area “Jæren” south west of Stavanger, it is recommended to have at least 100-200 meters depth. Closer to shore, it can be more rough sea conditions. I would then take the “Karmsund” fjord north to Haugesund. A few miles south of Haugesund, there is a reconstructed viking farm, based on archeological findings several places in Norway. Worth a visit. Also on the west side of the island Karmøy, in the village Visnes, is the old copper mine where the copper for the Statue of Liberty is from.

    Further north, the village Espevær might be worth a visit. Even further North, in the middle between Haugesund and Bergen, the village Bekkjavik is worth a visit. A popular and good restaurant there.

    Feel free to ask if you have any questions.

    • Trond,

      To ensure we do get as far north as we plan, we’re going to run relatively directly north to Tromso as the weather allows. We’ll then work our way slowly back south, exploring in more detail as we go. So we will save Haugesund and Bekkjavik for the return trip. Conditions in the North Sea right now are excellent, with less than 10 kts wind, but the wind is predicted to pick up from the north a bit tonight and more tomorrow as a small weather system passes. So we actually are planning to stop and anchor in the inlet on the west side of Espevær tomorrow and wait for that system to pass before continuing on. We’ll be there for a couple of nights so definitely plan to visit the village.

      Thank you very much for the advice and suggestions. A lot of the best places we’ve been to come from recommendations.


      • Trond Saetre says:

        In that case, I would suggest that from Espevær, you can take the “inshore” sheltered route northbound all the way to Måløy. This route can be done in almost all weather conditions, and is well marked and easy to navigate, day and night. It is used by the high speed passenger ferries as well. Then you need a good weather window to cross the Stadt peninsula.

        When passing the “Sletta” between Haugesund and Espevær:
        If the wind is between south west and north west, it is recommended to stay away from the shore, due to confused seas. Northern part of this area is usually the worst, with currents often coming from 3 directions.

        • That was super useful Trond. We hadn’t noticed that we could stay mostly inshore when heading north. That looks both more interesting and more sheltered. Thanks very much.

          • Trond Saetre says:

            Please see the link for a route suggestion, beginning south of Haugesund, and ending at Måløy, where you can wait (if required) for a weather window to cross Stadt.
            The chart can be used for navigation planning, as it is taken from the official Norwegian map authority.
            Haven’t any personal boating experience further North than this.


            • Thanks Trond. We just spent the last couple of hours studying your recommended route and it looks excellent. We plan to follow it. Thanks for the welcome to Norway and for sending us the trip planning ideas.

              Conditions continue to be excellent and we should be in Norway Tomorrow morning.

              • Trond Saetre says:

                Glad I can help. I have learned a lot from your technical info/blogs, so the help goes both ways. 🙂

                You should check out the website Barentswatch, for wave forecasts along the most exposed parts of the Norwegian coast. It is a government/ official service:

                For winds (and sea) forecasts, I find the most accurate.
                The Norwegian is not reliable enough, especially for winds, which at least for the west coast, is double compared to the forecasted. But the weather radar they have, is pretty good.

                You probably already know, but the official Norwegian pilot guides, can be downloaded for free here:

                • Sorry for your comment not appearing immediately. We get 100s blog spam comments per day and they are just about 100% removed automatically. We need to deal with the odd one that gets through and occasionally a note gets flagged for administrative approval. That’s what happened to your posting and I just approved it.

                  We’re “enjoying” a Norwegian ride out here with 30 knots of wind right on the bow creating short, steep waves. We’re currently pitching 17 degrees and rolling 8. An hour ago we did a 22.5 degree pitch cycle. I’m just glad we’re not in shallow water.

                  We’ve used in the past and like it although it’s currently under-estimating our wind conditions by a fairly large margin. Thanks for the reference to Barentswatch and the Pilot as well.

                  • Trond Saetre says:

                    With the wind you have now, you might want to follow this route, which ends where my first route begins. It is a few NM longer than the direct route, but is worth it if the seas are rough.
                    Notice the start point, which should be at least 0,5NM W of the YBY light buoy at “Jærens rev”. It is important to keep this distance, to avoid potential breaking waves. (Warnings in the pilot books)

                    Also, from your current position until the beginning of this route, it is recommended to keep enough distance to shore, that you have at least 100-200m water depth. This area, called Jæren, is one of the roughest ocean areas in Norway.

                    • Well, this body of water is definitely living up to it’s robust reputation :-). The winds are averaging 30 kts, gusts to 35, our 5 min max pitch is 17 degrees, and because of the heavy pitching, we’ve slowed down to the 6.0 to 6.5 kt range. We won’t be at the buoy that marks the start of the route you suggested for 6.5 to 7.0 hours in current conditions. Hopefully conditions will improve slightly but, if they don’t, it’s good to have some options. Thanks again.

                    • Trond Saetre says:

                      I see you make good progress. Hope you enjoy the scenery along the route.

                      After passing Stadt, you may choose a more or less sheltered inshore route almost to the city Molde, and there you need to head out for the open ocean. Notice that you need a good weather window to cross the exposed Hustadvika. (Beginning at the village Bud. This is another of the most rough ocean areas in Norway. Never use the narrow route close to shore in rough seas!
                      Further north, an ocean area called Folla, must also be respected.
                      In this chart (see link), I have roughly marked the 3 areas I know of, where you want a good weather window to cross:

                      Have a nice and safe trip.

                    • Thanks again for you local experience Trond. We’ve been enjoying the relatively sheltered inside route you recommended and have been finding the scenery incredible. In fact, so good we were drawn into the Sogefjordn Fjord. We’ll visit the rest of the Fjords on the way south but we decided we just had to explore and enjoy one now while the snow is still on the mountains.

                    • Trond Saetre says:

                      Sognefjorden (the world’s longest fjord), is mostly avoided for cruising. Reason is very few (if any) sheltered anchorages, and few guest harbors. But I agree, the scenery is spectacular!
                      On your way south, when stopping in Bergen: Spend a day and take the “Norway in a nutshell” tour: Train from Bergen past Voss to a tiny place called Myrdal, then change train down to the village Flåm, from there boat/ferry to Gudvangen and buss to Voss, and finally train back to Bergen.

                    • You’ll laugh but many of the reasons we’re heading down Sognefjorden are the ones you mentioned. Our interests here are: 1) it’s the biggest one, 2) many boaters don’t even go down it, 3) long time blog reader Jacques Vuye recommended the Flam Railway so we’ll definitely spend a day with it, 3) we want to visit the narrow Naeroyfjord, 4) we want to visit the Glaciers, and 4) the scenery is extraordinary. Your right that there are very few anchorages in the area but, as long as it’s not crowded (and we’re not expecting it to be) we’re fairly confident we’ll find anchorages that can work. We have a 70 kg (154 lbs) anchor with 500′ (152m) of chain rode so we can often find locations that work well that are passed up by others. But, I agree it Anchoring looks more challenging than usual in this area and we may have some adventures in front of us :-).

                    • Trond Saetre says:

                      At least you will be seeing some of the most spectacular scenery of this part of the country. A crowded anchorage there would be one boat only, and yours is definitely equipped for the most challenged anchorages. Adventures is what makes boating extra nice. Have fun!
                      By the way, it is often cheaper to buy gas for your dinghy engine, at regular gas stations than marinas. Also you hardly ever need cash in Norway. Most people use cards for everything. But if you need cash, get it from grocery stores instead of an ATM: You can ask for up to about 1000 kroner in cash when you buy groceries. (No visa/ mastercard transaction fees then). It’s an arrangement the grocery stores have with the banks. (Some stores only accept debet cards, though)

                    • We need you with us on all our trips Trond! Thanks very much for the steady stream of ideas, thoughts, and well timed suggestions. We certainly owe you at least a beer. If you ever find yourself in the vicinity of Dirona, let us know. It would be great to meet you in person.

                    • Trond Saetre says:

                      Thank you! I will definitely get in touch if we are in the same area. Hopefully the chance comes when you are heading south again.

                      Here are links to the Coast Radio (Kystradio) VHF radio channels in Norway. They can receive distress calls/ be the link between the resque center and the vessel in distress, provide weather forecasts on request, in addition to the scheduled forecasts, ship to/from shore phone calls, and a lot more… They should be contacted on the working channels, instead of 16.

                    • Thanks for the radio references. We are currently anchored in what will certainly rank in our world-wide top 10 list of great anchorages. We’re anchored in Indrefjord surrounded by tower peaks and waterfalls! Sognefjord overall is a gem.

                    • Trond Saetre says:

                      Here is a scanned pdf of the harbor guide for Flåm. Hope you have a great time.

                    • GREAT! We have an online version of that book and it’s very good. Wow, what a great spot we have here in Flam. It’s really beautiful here. What a country!

                    • Trond Saetre says:

                      Good to hear you do well. Hopefully there aren’t too many cruise ships (and loads of tourists) there at the same time.

                    • We took the Flon to Myrdal railway yesterday on the recommendation of long time blog reader and railway buff Jacques Vuye from France. It was an excellent trip. Lunch at AEgir Bryggeri and a great dinner on the outside deck of our boat enjoying the great weather. Today we’ll rent an electric car and head up the Stegastein viewpoint and perhaps do some exploring by tender as well.

                      It’s a good thing it’s the off season. Even now there are a surprisingly large number of tourists. I can’t imagine what it would be like with 2,000 tourists descending on the tiny town from a cruise ship arrival. We’ll be safely further north by that time :-).

                    • Trond Saetre says:

                      That railroad is spectacular! Have taken it a couple times myself. It is also very popular to do that trip on bikes, all the way from the Finse railway station at 1222 meters above sea level, via Myrdal down to Flom. But the first part is not available before the snow is gone, usually not recommended before late July.

                    • We did ask about the bike option but, as you predicted, they said it was too early in the year for that one but we could walk.

                    • Trond Saetre says:

                      About 8-10NM NNE of your current position, is a place called Selje. A nice place to visit, if you are waiting to cross Stadt. (Looks like tomorrow will be a good day for the crossing.)

                    • Yes, we were thinking of going around Stadt tomorrow and continuing North. We really enjoyed Sognefjord but want to see the Lofoten group and other Norwegian gems but I suspect we’ll be back in the Fjords earlier than originally planned. We just love them.

                    • Trond Saetre says:

                      Agreed! Lofoten is a “must see” area. Also, if you stop in Bodø, a guided RIB-tour to the Saltstraumen, is an adventure. This narrow fjord/ passage has one of the strongest currents in Norway. (Don’t go there with Dirona!)
                      A friend of mine is working as a RIB driver for one of the companies offering tours, and it was great fun when I did it 2 years ago.

                    • Sounds like fun. We did something that sounds similar to the Saltstraumen adventure you described in Australia. The Horizontal Waterfalls:

                    • Trond Saetre says:

                      The horizontal falls in Australia looks similar, on a smaller scale. The link is a wikipedia article about Saltstraumen.

                    • You’re right, the Norwegian version looks even bigger than Australia’s Horizontal Falls. We’ll have to check it out.

  13. Don Magie says:

    Hi James and Jennifer, I hope you are enjoying the Netherlands (I finally caught on that you have moved on from the UK).

    I am looking to replicate your work on struts for lifting the base/mattress in the master (on our 47 which should be essentially the same as yours I think). I wonder if you can share your experience for the characteristics of the struts and your location for installation.

    BTW, I have also had to replace my strut on the floor in the main salon down to the engine room. Seems like the original spec was a bad choice!

    Thanks in advance and I really enjoy your blog with all of the details. I am looking forward to trying to replicate some of your projects on Home Free.

    • Hey Don. Congratulations on the new boat. You can always see where we are in real time at:


      What we used to lift the master stateroom bed were a pair of 120 lb gas struts designed for heavy pickup truck box covers. The the structs are only $17 each at Amazon:


      You’ll also need these as appropriate for each end:


      It’s a really nice addition that makes using the wonderful space below the bed much simpler and somewhat safe to access.

  14. Schröder Hans-Joachim says:

    on your way further east you might want to stop at Helgoland. Taxes especially on Diesel are reduced.

  15. Peter Lefroy says:

    Why is Harlingen your first stop in Northern Europe?

  16. Timothy Daleo says:

    Great looking new tender. Are you going to transfer your equipment over to the new one or buy new electronics for it? Hope the three of you are doing well!

    • Hey Timothy. The only electronics we have in the tender is a $100 depth sounder so we’ll leave that with the boat. As another act of partial craziness, I plan to install NMEA2000 depth, GPS, and even connection to the Honda 50. I’m not sure when I’ll get time to do all that work but we’ll get to it and I’m really looking forward to seeing that new tender next Wednesday.

      • jan-kees says:

        Since you are going to Harlingen to pick up the tender, enjoy navigating the Waddenzee. it is a great place to find a spot to dry out with low tide and check the hull.

        • This boat isn’t stable on it’s keel when dry so I wouldn’t want to intentionally ground it in a non-emergency situation. We’ll be careful on the way into Harlingen.

      • Timothy Daleo says:

        Good luck with the tender today. I look forward to seeing the upgrades in the future. I hope all three of you are doing well.

        • Got it as scheduled first thing this morning. It’ll do 42mph in open water with three people in the boat. I think we are going to really like it.

          We have a bit of a fuel pressure issue, I need to chase down but I doubt it will be challenging to solve. Otherwise, all good.

  17. Evan Bauman says:

    James – was reading about your NMEA network crashing due to low battery voltage. Curious to know why you have a separate 12v system when you could easily install a 24v-to-12v converter and power all of your 12v devices from your monster 24v system. Is there any significant advantage in having a separate bus?

    • I do have a 24 to 12v converter but there is also a battery on the 12V side to ensure that convert faults don’t take down the 12V bus. I screwed up and accidentally shut off the 24v to 12V converter. It’s easy to alarm on faults (or human error) and I’ll make that change so it doesn’t happen again.

  18. Tim says:

    Hi James:

    Looks like you are enjoying the British Isles!!

    On your Maretron I see you monitor battery state of charge, as do I, but separately for all four house banks and the start battery banks. As you know, the BSOC is a calculation from other parameters that the sensors measure. When we are at the dock, or in anchorages, the BSOC is working fine and moving up/down as it should during charge/discharge cycles. But when underway and the charge to the batteries is provided by the main engine alternators, the BSOC just declines till it hits zero. Maretron says it has to do with the charge efficiency setting, but I don’t think so.

    The main engine alternators are attached to the same bus as the batteries and chargers, and provide the charge to the batteries, as needed, depending if we are leaving the dock fully charged or exiting an anchorage with the batteries depleted requiring charging. However, once the batteries are fully charged, while they go into float condition with very little current going in/out as the alternators keep them fully charged (as noted by the voltage remaining steady in the 26.3V range with amperage fluctuating around zero on the house battery banks), the alternators DO NOT go into float as they are still generating power as required to fulfill the AC system demand through the inverter. As these components are all connected to the same bus, I am wondering if the four house bank current sensors are somehow sensing this load requirement to the AC through the inverters and assuming it is a draw on the house banks, therefore resulting in a calculated decline of battery state of charge, even though the batteries are fully charged and in float.

    Do you have this issue or have any thoughts on this?


    • Hi Tim. Good hearing from you. Yes, I recognize those two problems. They are both a bit challenging but both are addressable. Unfortunately, neither is a simple topic so this can’t help but be a bit longer than ideal for a blog question. I’ll answer it here but will end up filling it in and posting as a full blog entry.

      On the first question, battery State of Charge (SoC ), the best solution is not to use it. You are right that I display a state of charge in our system and I have invested quite a bit in getting a more accurate SoC report but it’s been a hassle and I’m pretty sure it’s not worth the effort. There are some proxies that are quite accurate and far easier that I’ll cover below. I’ll start with what I use instead and then we can circle back to why SoC is inaccurate and what I have done in an effort to get a more accurate reading.

      I use voltage and current as a proxy for state of charge when the system is discharging. The relationship between voltage and current is a complex surface (I’ll return to this below) but most of the time your boat is at a fixed, and not particularly heavy discharge rate. When there are no heavy, intermittent loads on your batteries and it’s just the steady background discharge rate, the voltage will closely match the discharge curves shown on page 34 of the Lifeline Technical Manual ( Of course, if you are using some other battery manufacturer, you must use their data but I’m using Lifeline as an example as they are a common choice and I use them on Dirona.

      If the batteries on your boat would need to be charged twice a day (likely) then you are on an approximate 24hr discharge cycle since they need to be recharged at roughly 50% charge. Assuming that you are on a roughly 24hr discharge cycle, you can use the 20 hour discharge cycle curve from that graph to get the relationship between voltage and state of charge when you have no big loads on your system.

      Of course the absolute most accurate approach is to disconnect the batteries and use the State of Charge vs Open Circuit Voltage on page 33 of the Lifeline manual. This is highly accurate but not practical on a boat during use. What I do is have battery voltage prominently display and learn to look when the system has no abnormal loads and the state of charge is a fairly accurate function of the voltage level with 24.2 to 24.3V being roughly 50% on a 24V boat and half that for a 12V boat.

      Why not just get SOC correct? The short answer is its really hard and every manufacturers SOC indicator that I’ve looked at measures the same things and has the same inaccuracies and these inaccuracies are so large under some circumstances that the SoC reading is close to valueless. What all commercial SoC calculators that I’ve looked at measure is the current leaving the battery and the current going back in. They know the charge efficiency (entered by the user) so they know how much extra current must go in to achieve a 100% charge. Just a bit more than what came out.

      Generally these systems are very accurate through a small number of charge/discharge cycles. But batteries are complex chemical systems and they transitions they are going through change over time and so the charge efficiency and, more important, battery capacity isn’t fixed and will change over time. Because they are tracking current in and out, even small errors become additive over time and the inaccuracies can mount quickly.

      The system can be reset by charging to 100% but the inaccuracies will creep back in as you go through charge/discharge cycles. You can work hard to tune the charge efficiency and you will get the commercial systems far more accurate but they will never be great. Consequently I use voltage at a known discharge rate as a proxy. It works well and is fairly accurate but it won’t work when the kettle is on (not the steady, background discharge rate you have calibrated for) and it won’t work when charging (not on the steady discharge rate).

      The voltage as a proxy for charge levels works fairly well and it works far more accurately than any commercial SOC measure I’ve seen so this is my primary tool. For generator autostart, I automate the finding of the fixed, background discharge rate by averaging voltage over 15 min and this works very well and yields a very precise generator start signal. In many ways, this completely solves the problem in that, if the generator starts when needed, I don’t have to worry about SoC.
      But, I couldn’t resist doing my own SOC calculations since I would like to be able to display that data accurately. If I display the SOC computed by using the 20 hour discharge curve from the Lifeline manual. This is wonderful and works very well but has a few issues: 1) it won’t show SOC during charging, and 2) it will not produce a reliable number if you are going through a prolonged heavier than normal discharge cycle.

      Since the data in the Lifeline manual appears fairly accurate, I decided to program not just the 20 hour curve but to also use the 1hr, 2hr, 4hr, 8hr, 20hr, and 120hr curves. I then curve fit the data to produce a 2 dimensional mathematical surface that returns SOC from current discharge rate and voltage. I implemented this and it mathematically worked fine but the Lifeline data at deeper discharge rates on used batteries is not accurate and ends up producing unstable results. My simple system of averaging voltage over 15 min and looking it up on the single dimensional 20 hour discharge curve actually worked better so I reluctantly ditched the complex multi-dimensional curve fit.

      But, I’m a sucker for punishment and I couldn’t leave SoC alone. Even though showing the function computed using the 20hr discharge curve and the voltage averaged over 15 min works very well, I still wanted to get a better SOC number. Clearly I should have left it alone but I would love to have accurate SOC even when charging and the discharge curve won’t help you under those conditions.

      I’ve invested some time in refining this and it is better than commercial systems I’ve looked at but the complexity wasn’t worth it. In this model I note that the commercial SOC calculation systems are very accurate at a few charge/discharge cycles but the errors mount over time and get less accurate. Once the batteries are returned to 100%, the SOC is re-calibrated, it again is accurate. Understanding this, I decided to use the commercial SOC number but calibrate it more frequently.
      Rather than just calibrating it at 100% charge, I use the 20 hr discharge curve and, since we know it is accurate when the boat hasn’t had any recent discharges, my automation waits until the discharge rate has been very stable for a long period of time and then corrects the SOC to match the 20 hr discharge voltage curve (actually a modification of it that slightly more closely matches the background discharge rate on Dirona). I then use this SoC bias to recalibrate the commercial SoC and report the commercial number with my bias. This combines the accuracy of the commercial SoC system computing current in and current out but corrects the system error that creeps into these systems over charge/discharge cycles.

      This synthetic SOC calculation is still not perfect but its good enough that I again show SOC in the N2kview display. The generator still is started on the 15 min averaged voltage which is simpler and seems very accurate but I display the SOC using the calculated bias as described above. Because I had a solution for the generator autostart years ago that works well and I’m used to reading voltage myself, it’s certainly not worth the work of trying to get SOC to work but that’s what I did.

      So, with that background, looping back to your question, should your state of charge be incredibly inaccurate? No, it should produce fairly accurate results for a handful of charge/discharge cycles if set up correctly. Make sure the Peukert function is correctly set for your battery type. Lifeline recommends 1.12. Make sure the capacity of your bank is set correctly. It turns out this is both very important to accurate SOC but they are also hard to get right. Bank capacity will fall slowly over time as the batteries are used. But, capacity will also fall somewhat more quickly as the system is taken through partial charge/discharge cycles. You eventually will need to equalize (Lifeline calls this “conditioning”) and, after each equalization, you will return more closely (but not quite) to your original capacity. The battery bank capacity is always changing and it’s very difficult to know what the current capacity actually is to accurate report SoC.

      As I said previously batteries are complex chemical systems that are changing all time so, if you get all these parameters right once, they will again be inaccurate sometime later. But, yes, you can get them right and get acceptable results for a period. I personally don’t find it worthwhile so just use voltage as a proxy and continue to work on the accuracy of my synthetic SOC calculation. Where I end up on this is recommending not to invest time in SOC and just use voltage with knowledge of the background, steady-state discharge rate. It’s a “good enough” data point and I find it’s actually excellent for driving our generator start signal.

      The second question you asked Tim was “Once the batteries are fully charged, while they go into float condition with very little current going in/out as the alternators keep them fully charged (as noted by the voltage remaining steady in the 26.3V range with amperage fluctuating around zero on the house battery banks), the alternators DO NOT go into float as they are still generating power as required to fulfill the AC system demand through the inverter.”

      It’s a great question. The short answer is that this can be “easily” solved by the charger and, for the alternators, the voltage regulator suppliers. If they measured the current going into the batteries then, with the voltage, they will know exactly the state of charge of the batteries and could fairly easily know the difference between supplying 75A to the house with the batteries taking nearly no current (high house draw with charged batteries) and the same 75A charge rate where 50A is going to the battery (Batteries nearing full charge but not yet there).

      However “easy” this might be, manufacturers of alternator voltage regulators and chargers don’t measure the current at the batteries and instead just measure the current output at the source (the chargers or alternators) and use this data as an estimate for what the batteries are consuming. For the reason you mention and I outline above, this often doesn’t work. A high house draw will look very similar to batteries still charging. I suspect that charger manufactures don’t like the installation complexity of measuring the current at the batteries so instead using the current at the source as a proxy for current at the batteries. In actuality, as bad as that is, most alternator regulators don’t even measure output at source. Instead they measure field strength in the alternator and use that as a proxy for current produced which is a proxy for current being sent to the batteries.

      Naturally, this approach doesn’t work well. It’ll work fine if the boat is just charging but if there are large house draws, it will compound the calculations. Some chargers like Victron Centaur ( use a time driven algorithm and run for 4 hours in bulk and absorption. These fixed time schedule approaches are a disaster and need to be avoided. Some like Mastervolt provide a vast number of parameters that can be changed but they essentially leave the problem up to you. This is not idea but, in the absence of measuring and using the current going into the batteries, this is best you can get and, although current isn’t known, voltage is known and this actually does give an accurate view of how close the batteries are to full charge. So, the data is there is get the system working right so if enough flexibility and tuning is offered, the system can be setup to work correctly and not abuse the batteries.
      On Dirona, we use a Balmar MC-624 ( to control each alternator and Mastervolt 24-100/3 battery chargers. Neither measure the current heading into the batteries but, since the voltage level goes up during the absorption phase, you can still tune these systems to use voltage as a proxy for charge level and get the behavior you want.
      What I did was reads the short Lifeline Technical Manual ( and program the Mastervolt and Balmar systems to deliver the closest match to what Lifeline wants under our usage patterns. I can share the configurations I’m currently using on Dirona as a starting point. It’s not quite as good as measuring the current flowing to the batteries but seems to work fairly well. The important thing is to not allow the system to go into bulk or absorption during high current consumption in the house and stay there for long periods on charged batteries. This is very bad for the batteries. Your two goals are to: 1) fully charge the batteries, and 2) back off to float and just feed your battery recommended float voltage the rest of the time.

      • Tim says:

        Hi James:

        Thanks so much for the response and detailed information. There is a lot to consume in your reply, but the jist of it is that I am likely correct in my assumption as to why the BSOC is not reading “correctly” while underway with the alternators providing the charge. I agree with you in that I use voltage and amperage as the proxy to ensure that things are working as they should an my experience over three years on the boat tells me that it is. I ran over this information with Lifeline and they concur. Like you say, without spending an inordinate amount of time on something that can be achieved in other ways, I will look at a few options before moving on to other issues.

        I will also take into account your comments on the other response related to Maretron for the ongoing management of the system. While I agree that spares can allow the system to get up running again quickly, some of the components are not cheep. For example, the one favorite that everyone seems to be having an issue with, the WSO100, is $1000. That’s not cheap for a chunk of plastic (I know there are some intricate things inside the plastic). Now I am up to three failures in three years, so I have you beat.

        PS….what are you doing up all night?!?!?



        • I agree that the Maretron gear is not cheap but it actually is relatively inexpensive compared to competitive monitoring systems. Your WSO100 at $1000 prices seems way high. You can have them for $566 on Amazon:

          I generally get 2 to 3 years from them. I took the last one apart to understand the failure mode and it was water leaking in between the top and bottom covers. I suspect they might last longer if nobody touches them when working up on the stack. I’ve been careful and it may make a difference. I’ve been told that the Airmar NMEA2000 weather sensor is more reliable but I’ve not seen it for less than $1,000 so I haven’t yet headed in that direction.

        • Chris Barber says:

          Hi Tim, as to your battery monitor perceiving constant drawdown while underway, are you saying that the current shunt that provides battery current to the BSOC is seeing the current provided by the alternator as battery discharge current? What I do is monitor current on the battery independently, so that if the alternator is supporting loads while the battery is in float and not asking for much current, the BSOC only sees the that tiny float current as charge (+) current to the battery and does not see any load current that is not coming out of the battery as actual discharge (-) current. i.e. it sees only the true charge and discharge current on the battery. Is that what’s making the difference for you?

          • Chris raises an excellent point. For battery SoC to have even a prayer of working the current transducer has to be between the batteries on one side and the charge source and house loads together on the other side. If the current transducer is between the load and the charge source, it’ll be almost random. And if there is load that doesn’t flow the transducer, the readings will be a mess.

            • Chris Barber says:

              Thanks James. I got the feeling that Tim’s current information was coming from the inverter or the alternator controller or something that wasn’t purely battery in / battery out. Tim, if we understand you correctly in this, this can be solved pretty easily.

        • Chris Barber says:

          I read “chunk” as “junk” three times before I got it right. Or did I have it right in the first place?

      • Chris Barber says:

        James, I couldn’t have said it better myself, with 30 odd years in the industry including a lot of hardware and software involved in BSOC!

  19. Sean says:

    From Falmouth: “The weird things is zinc life has been improving. They started looking good after 2 months, so we want to 3. Then they started looking great at 3 months, so we went to 4.”

    Is there any risk something else in the system has taken on the role of sacrificial anode?


    • The zincs are to protect the hydraulic heat exchanger. Since it’s not bonded or connected to other systems so I don’t think they can be protecting other components or other components can be protecting the heat exchanger. I suspect the reason the zincs are lasing longer is the boat has been underway less recently but it might also be the colder water.

  20. Mark says:

    Hi James, I am having trouble sourcing Lifeline batteries in Australia for our sistership to Dirona. I believe that you may have had a similar problem when you were in NZ. Your advice would be appreciated please?

    • Getting the batteries from the US will work fine for you but you will likely need to pay duty so you need to check on that cost as well. I strongly suspect buying the batteries from the US will still be a big win for you but you should check. When we were in New Zealand there was no duty since we were a visiting yacht.

      We bought the batteries from DC Battery Specialists ( Great company.

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