This electrical system digression has had some unexpected benefits. Apparently, I’m not the only one annoyed by imperfect system integration. I can totally relate to his irritation.

I’ve been spending more time on YouTube (welcome to 2011). While I still feel like 99.9% of it isn’t interesting to me, there are still some great finds there. I may try some more videos, myself. Though, I’ll still be posting them on Vimeo. (These people are far more good-looking, though. I was born to communicate by the written word…)

I set the Max Charge rate to 90%. The charger specifications say that it will only pump a maximum of 125 amps into the batteries, but when we pulled into port and plugged in yesterday, there were 132 amps going in. The max charge rate (C/5) of 600 amp hour batteries is about 120. Now, the amp meter function of the inverter/charger (without the BMK) is only accurate to within 20%. Plus the solar charger may have been pumping in some amps. But just in case I bumped it down and it dropped to a much more battery-life-friendly 114 amps.

[EDIT – back in May I set max charge back to 100%. Per the specs, the batteries can take up to 300 amps during bulk, so 132 should be fine]

Next, I need to reconfigure the solar charger to match the charge profile of the shore power charger, and get rid of the monthly “equalize” function, which I think might be death for AGMs…

This is a bit of a long one, and I am still not done figuring it out. But, it was one of those issues that lead me down a rabbit hole, and when I came out the other side I knew a ton more about how the boat works. 

  • Thing #1 – When we were at anchor and the house banks were at 53%, the solar panels didn’t seem to be putting out enough charge. 
  • Thing #2 – After plugging into shore power at 77% SOC, the Magnum shore power charger just went straight to float (instead of bulk, as expected). The next day, the house banks were still only at 80%, but the charger said “battery full”. 

This lead me down a winding path of poorly-translated charger manuals, battery theory, and system integration philosophy, which I will mostly leave out here. But, here’s what I learned in the nutshell. 

When the batteries were low and I saw this on the charger:

I’m like, “Why aren’t the panels putting out as much as possible? Shouldn’t they be in ‘Bulk’?” The answer was, of course, that they were. “Bulk” charging just means that the charger is putting as much as it can into the batteries. In this case, the panels are generating 88.56 watts, which the MPPT charger is converting into something that the DC system can use, in this case 7.7 amps at 12.5 volts (though, how it’s converting it up to 96.25 watts is a question for another day). The voltage is determined by the resistance of the battery, not by some setting on the charger. So the charger cranks as much current (amps) into the battery as possible and the voltage builds as the battery resists the charge. In this case, the sun was still relatively low in the sky.

Lesson Learned #1 – The solar MPPT charger will push as much current into the batteries as it can up until the voltage hits the absorb setting (14.4v in this case). If the sun is low or obscured, it will be less than if the sun is directly overhead. I thought that the voltage of the system was a set value, but that’s only true when the batteries are charged enough that they create some resistance to the charging sources. Once that resistance passes the absorb threshold, the charger will hold the voltage stable and continue to lower the charge to keep it there.

Lesson Learned #2 – The reported voltage of the DC system is a combination of all of the load, all of the charge, and passive resistance of the various components.

In practice this means that the voltage I see on different components will be different. So, in this case, the panels saw 12.5v. But, the battery monitor saw 12.31v. So we’re seeing a .3v difference between the charge output and all of the resistance in the system (the batteries and any devices using power).

Since the battery monitor (BMK) is a shunt that is the last link between all of the negative bus items and the battery, it is the most accurate measure of the voltage on the negative battery terminal.

Note that the solar charger is bridged directly to the charging input on the positive side of the batteries.

So any current from the solar panels is combined with current from the charger.

Lesson Learned #3 – the reported current in the system will be different depending on where it’s being measured. This one really confused me. I was trying to do simple math – if the DC + AC loads are X (a negative number) and the solar panels are outputting Y, the the reported load on the battery monitor should be X + Y. Nope. While that’s generally true, there are so many devices on the system (all fluctuating) the numbers will not add up exactly. Ultimately, the battery monitor will tell you what is going into or coming out of the house bank. But, trying to add up the loads across the system is imprecise. However, it is directionally true. So, at one point, the sun got bright enough and the batteries were charged enough (we ran the generator) that the resistance (voltage) increased and we saw a net surplus on the BMK. This means the sun was charging the batteries enough to produce a small surplus (over the house loads).

Also, the components all measure with different levels of precision. From the manual: “The DC Amps meter displays the amount of current going in or out of the battery. A negative number shows the amount of current being removed from the battery. A positive number shows the amount of current delivered to the batteries. This meter converts AC amps to display DC amps, so the accuracy below one amp AC (~10 amps DC @ 12 VDC) is not detected. When the current detected is greater than one amp AC, the accuracy of this meter is ±20%.” I’ll trust the BMK more than the regular DC volts.

Lesson Learned #4 – There are race conditions between the three phase solar panel charger and the three phase shore power charger. Each are using different voltage levels and thresholds for absorb and float settings. Also, since voltage is a trigger, the charging volts from one system can cause the other to go into an incorrect state. In most cases, this just means that the chargers take turns doing what they can to charge the batteries, (backing off when the other one is working harder). In some cases, it can prevent charging.  This has been a problem for a while.

In our real-world example, we returned from a cruise at 77% SOC with tons of sun. When we plugged into shore power, the solar panels were producing enough current (20.9A) that the battery was resisting at 13.7v, so the shore power charger went right into float (13.3 volts at the shunt). This is by design! From the manual: “If the battery is >13.0 VDC… then the battery was already charged and the charger automatically goes to Float charging to keep from overcharging the batteries.”

The next day, the batteries were still at 80%, though the charger said “full” Once again, this was explained in the manual. “After four hours of float charging, the charger turns off and “Full Charge” displays (charger is now in Battery SaverTM mode). If the battery voltage drops to ≥12.6v… the charger automatically initiates another four hours of float charging.” But, what happened is, the solar panels + shore power float got the batteries to 80% (~12.7v), so the second float cycle was never triggered.

The best way to avoid this is to force a Bulk / Absorb / Float cycle when you first plug into shore power. There’s a function on the Magnum remote under CTRL to do just this. When I tried it, the charger jumped into bulk and very quickly hit absorb. Right now, the absorb cycle is set to run for two hours, which is about right to get from an 80% charge to float.

There will be other race conditions. This is exacerbated by the chargers having slightly different set points for their various modes and triggers.

Start Bulk IfStart AbsorbAbsorb timeFloatBattery fullSkip to float
Magnum<= 12.8v>= 14.5v2 hrs13.5v for 4 hoursafter 4 hours float*>=12.9v
Tracer<= 12.6 (?)>= 14.4v2 hrs13.8vNA – stays in float if possibleNA

*When in “battery full” mode. The Magnum will enter absorb if the voltage drops to 12.6 and bulk if it drops to 12.1. 

Lesson Learned #5 – System integration is hard. The Tracer MPPT Solar charger uses different defaults than the Magnum. The magnum was set to the “wrong” type of AGM (Lifeline) (though since these are OEM batteries, there are no specs immediately available). There are also a number of settings like maximum charge rate, Absorb cycle time, etc. that probably need to be optimized. Don’t rely on the default settings and don’t assume the builder/commissioner set it up right. Even solid boats with experienced owners get this wrong.

Also, for posterity, here’s the cheatsheet for charge level per voltage for AGMs.

  • 100% – 12.8v+
  • 75% – 12.6v
  • 50% – 12.3v
  • ‘25% – 12.00v

We just passed 100 hours on the main.

I’m not sure when the official one year anniversary is, since the way we did the financing we actually owned her before she landed. She splashed on 17-Jun-2020 and I first boarded her in Blaine on 20-Jun-2020. Commissioning was complete on 11-Aug-2020. Regardless, 100 hours in eight months ain’t bad for two people with kids who work full time.

Now that Turtle’s not a new boat any more, it’s time to turn my attention to the potatoes* of boat ownership – maintenance. I decided a long time ago to embrace boat maintenance (I still reserve the right to whine about home maintenance). I’ll quote myself from the manual I wrote for my old boat:

“The two happiest days of a boat owner’s life are the day they buy it and the day they sell it.” 

I hate that saying. Yes, boats need maintenance. The sea is relentlessly pulling her apart and it’s your job to make sure she stays together. How you address the need for this maintenance will determine whether you enjoy owning a boat or whether the old saw becomes true. You can either perform maintenance yourself, which requires time and patience, or hire someone to do it for you, which costs money…. But, ultimately, you’re the owner – and it’s not always easy to find someone to do the work. Someday you will be stuck somewhere with something broken (hopefully it’s something minor) and there will be no one around to fix it. Your goal should be to learn how do to as much as possible yourself.


This is part of why I fell in love with the NP: Everything is designed for maintenance. If it’s not stainless steel, it’s accessible and serviceable. Now, every NP is custom, which is really nice for BS-ing with other boat owners (“what’s she powered by?”). But, it also means they don’t really come with a manual. In fact, they come with several:

Note the stylish handbag…

Boat maintenance is a journey, not a destination. The more I learn, the more I realize I don’t know. I still make stupid mistakes all the time (last weekend I spent five minutes troubleshooting the outboard, only to realize I hadn’t put the clip on the auto-kill switch). This beginner mind is humbling, but it also leads to over-cautiousness and probably far more anxiety than it should. But, so far my approach of “do your best and ask for help” seems to be working.

So, what to do for maintenance? I have some experience with this on my old boat, but it’s hard to know when to follow the recommended intervals and when to disregard them. Cummins, for example, recommends checking the gear oil daily. The engine oil change interval is 250 hours or 6 months, whichever is sooner. So, these guidelines are clearly for a motor that is being used every day. But, the intervals can and should be different for one that sits for weeks at a time. This is one place where I feel like North Pacific could be a little more structured in what they prepare for owners. Even if every boat is unique, having some kind of guidelines – something like the book people prepare for putting a boat into charter – would be incredibly helpful.

Since that doesn’t exist, I’ll have to write it.

As with most big hard problems that I don’t know how to solve, the best place to start is probably with a simple list. For each system, I’ll crack the included manuals and leverage the community to figure out what the real interval should be (though asking for advice on trawler forum can be like asking a bunch of pre-schoolers who the best Avenger is…). I don’t expect I’ll ever be “done” with this. But, I expect in a few years it will stabilize.

  • Main Engine
    • Oil and Filters
    • Primary and secondary fuel filters
    • Inspect / replace pencil anodes
    • Re-torque engine mounts (there are no factory specs for this – any suggestions?)
    • Re-torque shaft couplings
    • Change gear oil
    • Flush coolant
    • Inspect belts
    • Flush aftercooler
    • heat exchanger (?)
    • Raw water pump (impeller)
    • fresh water pump (?)
  • Generator
    • Oil and filter
    • primary and secondary fuel filters
    • zincs
    • flush coolant
    • belts
    • heat exchanger (?)
  • Water Maker
    • clean /change media filters
    • change high pressure oil
    • change membranes (~10 years)
  • Dinghy
    • Change oil and filter
    • inspect prop (need spare pin)
    • charge / change battery
    • change plugs
    • anodes (there must be some in there)
  • Hydronic system
    • Fuel filter
    • Clean inside unit
  • Bottom
    • Inspect and replace zincs (2-3 x year)
    • Bottom cleaning (2-3 x year)
    • Bottom paint (~2 years)
  • Misc
    • Change fresh water filters
    • Inspect through hulls (open and close, look for rust)
    • Test bilge pumps
    • Test / Replace batteries
    • Thrusters (?)
    • Propane (fill and inspect)
    • Grease steering coupling
    • heads (?)
    • Grease windlass
    • Wax hull

*as in “meat and…”

I met some new North Pacific customers the other day and they reminded me that I have one of the most popular North Pacific Enthusiast Sites on the Internet. All four of my readers demand content! (Just kidding, it was lovely meeting you – hope your build goes smoothly!).

Turtle has float gauges in her fuel tanks. Also, the engine data is not currently bridged to the NMEA 2000 network. This means that my fuel levels are ballpark and the burn rate that I get from the engine only shows up on one gauge, and can’t be used for calculations on the chart plotter. So, if I want MPG or average burn at different speeds, it’s a manual calculation. Not a big deal, but kind of a pain, given there’s more than enough compute on board to record this. [Apparently, I can bridge the engine data to the NMEA 2000 network via the Mercury vessel view, but I just don’t care enough right now].

Anyway, there are also site gauges on the tanks. We did a fuel up trip to Des Moines.

  • 320 gallons total @ $2.659/gal
  • Starboard – 182 gallons going from 8.5 to 41 on the site gauge. Float gauge went from 1/5 tank to 3/5 tank.
  • Port – 138 gallons going from 12.5 to 38.5 on the site gauge. Float gauge went from 1/4 tank to 3/5 tank (I put more in the starboard to counteract the list caused by the dinghy motor – that’s a subject for another post).

While there, I noticed that the top of the site gauge was nowhere near the top of the tank. I gave Trevor a call and he sent me the following diagram:

Note that the actual size of the tank is 347 gal.

Regardless this means that:

  • When the fuel is at the top of the site gauge, I have ~87 more gallons to fill in the tank
  • When it is at the bottom, I have ~43 more gallons

With 694 gallons total, 25% of the total fuel capacity is above the site gauges and 12.4% is below. Said another way, at my typical 3 gph / 7 kt burn rate, 406 miles are above the gauges and 200 are below (with a total range of ~1619 nm). Currents, conditions, variable speed, generator, hydronic all notwithstanding…

I also know the general shape of the tank from early drawings.

Sizes are in mm. After some very back-of-the-napkin math to convert 347 gallons to cubic mm – in a tank with an upside-down parallelogram-trapezoid-ish shape, each tick on the site gauge is ~5.5 gallons – more towards the top and less toward the bottom. So, basically, the level will drop faster as the fuel is drained from the tank.

Ultimately, I should get some better fuel sensors in the tanks and bridge them to the chartplotter so I don’t need to futz with this. But, now that I figured it out, it hardly seems worth it.

We’re in the April 2021 issue of Passagemaker:

We actually purchased this picture from Noelle. Here’s the full version:

This is actually the second time we’ve been in Passagemaker. Oh, the paparazzi! They just can’t get enough of us. Here’s that moment from the other side (taken from my phone).

I always feel like I need to explain how we wound up so close to the Orcas. I explain it a bit in the video post, but to summarize again: we put the boat in neutral several hundred yards south of the pod. There was a south wind blowing us north. The Orcas were swimming back and forth (east and west) and slowing making their way south. Once or twice, we tried to reposition to the west, toward the shore, so they would pass behind us, but the pod wasn’t moving predictably and covered a lot of ground (they would disappear for minutes at a time and then resurface someplace new). It wasn’t actually easy predicting where they were going so we could be out of the way as they approached. So, we eventually just sat there and they swam right up to and past our boat. We would have had to run away from them to keep distance – and at a certain point they were close enough that we felt it was safer to keep the boat in neutral and let them decide.

Most people have been super nice about this, but there are always haters (someone accused us of feeding them). The one thing you can always rely on is people passing judgement on situations they weren’t present at to confirm their biases about human nature… and then posting it on Facebook….


We got AIS working. We applied through the FCC, which requires a station license as well, but this was necessary for international waters (Hello, Canada! Looking forward to hanging out after the virus!) There’s a post on Trawler Forum with step-by-step instructions. To the FCC’s credit, we got our number a couple of days after applying.

The MMSI needs to be programmed into each device separately. We have a Vesper XB-8000 AIS which runs headless, so you need to connect to it using an app over it’s dedicated WiFi network (why can’t boat electronics just be added to the ship’s WiFi network?!) So I added the MMSI and Station ID over the WatchMate app. You need to get this right since I think they only let you do it once or twice before you need to send it in for a reset. This is weird because MMSIs aren’t transferrable. Anyway. We got it added there and I also added it to the Pilot House Garmin VHF for DSC. I still need to add it to the radio on the flybridge.

After adding it, I was surprised to find we weren’t on Marine Traffic, even after several days when all of our neighbors were. I ran through the Vesper troubleshooting and it looked like everything was working. So, eventually North Pacific sent a Marine Electronics expert out to help. Turns out the NMEA-2000 bus is powered by the same breaker that the chart plotter is on. So, when the chart-plotter breaker is off, the whole NMEA-2000 network is down. Now, honestly, the AIS broadcast shouldn’t need the NMEA-2000 network to work. But, once we powered it on we showed up on Marine Traffic.

My leading theory here is that it wasn’t actually the NMEA-2000 bus. It was just that the AIS data on Marine Traffic is crowd-sourced, and it took several days to get all of our information uploaded. Regardless, it’s good to know that we need to keep that breaker on for anything to go across the NMEA-2K network.

Duncan from Puget Marine electronics went over a few other things – mostly getting our engine data onto the NMEA-2K bus so we can access it from the multi-function displays. He also priced out some fuel tank gauges for us, since we only have dumb floats in there now, and I’d like to use one of the built-in boat computers to calculate MPG and other data for us (we only have live burn rate right now).

Regardless, here we are on Marine Traffic, if you want to follow along.

We went for a nice overnight in Manzanita Bay. Being moored in Kitsap is providing some unexpected advantages. While Shilshole is a better location for just about any trip, you have to deal with the open Sound, making weather windows a bigger issue – even for overnights. Liberty Bay and Port Orchard are part of the more sheltered western side of the Sound – protected by the islands and Kitsap peninsula. When there are 4′ rollers on the East side of Bainbridge, the West side can be relatively calm. So, we cruised 3.5 miles from our marina to drop anchor 2.6 miles from our house (as the crow flies) for a lovely, sheltered night (weather was from the S/SE, so we were sheltered by the bay).

This gave me a chance to gather some data on power consumption during the “worst-case scenario” – hydronic heat running 24/7 and no sun for the solar panels. We dropped anchor at 2:20 pm with 100% charge in our 600AH AGM house bank. Over the course of the day, we did zero power conservation – we ran the hydronic heat, left the navigation electronics on, (so we had the anchor drag alarm), and we even streamed a movie (the Dark Knight – our little cellular connection really struggled). Depending on whether the heat and/or fridge were running, we were consuming between 12 and 20 amps at any given time. The solar panels were putting out less than an amp.

At 7am, the banks were down to 53%, meaning we’d used about 280 amp hours over 16.5 hours, or about 17 amps per hour. We ran the generator for two hours, returning the banks to 73% – about 60 amps per hour (or 10% charge per hour). This seems a little slow for bulk charging, but isn’t that far off from what I expected.

All-in-all its about what I expected. A few thoughts.

  • The solar panels can make a huge difference. During our summer cruise, on bright days, I saw them putting out 18-20 amps at 14V, which would pretty much run the boat and recharge the batteries. Realistically, they do about 6-8 amps for most of the day, which is enough to run the fridge.
  • The 24V charger was drawing a surprising amount – this system transfers power from the house bank to the windlass/thruster banks via the inverter. It was hard to get a precise measurement, but I’d say 3-5 amps.
  • The hydronic + fridge drew between 6 and 10 amps.
  • TLDR; in winter at anchor, we’ll need to run the generator for 2-3 hours per day. We can probably optimize this a little, but not much.
  • In summer at anchor, we’ll need to run the generator for 1-2 hours every-other-day. With a lot of sun, the panels put out plenty of power and – coupled with not needing the heat – there’s a chance we could go for several days without needing the generator.

Chris from North Pacific came out to our marina in Kitsap for a maintenance day. While he couldn’t find any obvious leak, he reassembled all of the connections to the boiler. Since it was only leaking a small amount, we’ll have to run it for a while to see if this addresses it. He also replaced a faulty heater fan and a couple of broken ducts. He also re-bed the screws in the pilothouse horn and replaced the gasket on the port fuel tank site gauge.

While on the trip, I got al little frustrated with all of the little bugs and hassles, but these are truly minor shakedown issues compared to some boats. We have about 80 hours on the main now – and ran the hydronic for 10 days straight – so it’s not surprising that things are settling in. Most of my stress was because I was doing the work… but the boat is under warranty. Trevor told me to just write everything down and send it to him and he would take care of it. And, he did! Very pleased with the service by Chris and North Pacific.

We got our MMSI from the FCC and I programmed it into the AIS transponder and one of the VHF radios. I still can’t see us on Marine Traffic, though it says it’s broadcasting.

The Christmas trip was wonderful.

We’re prepping for our big Christmas trip. We take one every year (except last year, when we were “between boats”). There’s still a long list of bugs to squash and small inconveniences to remedy. Onward!

Hot Coolant Smell

North Pacific has been working with me on the smell coming from the hydronic heat. First they arranged to for a visit by a tech from Seattle Boat Works (the local dealer for ITR, who makes our Hurricane Chinook hydronic system). In a weird twist of fate he was anchored just outside of our marina in Liberty Bay. Alex and I swapped out a couple lengths of hose and both of the heat exchangers under the bed, but the smell was still there. So, Trevor sent in the big gun: Dave Rasmussen, who did the original install, came down from Blaine to help troubleshoot. (Trevor has been adamant about fixing this before our trip). As Alex and I came to suspect, the smell was coming off the fiberglass wrapping around the exhaust elbow, which is just under the galley. There’s a fairly large air gap, which allows air from the engine room and bilge to flow into the space under the bed in the midship cabin; and, the fans on the heater cores were pulling in the air from the compartment with the exhaust elbow (not to mention some furnace exhaust, which was coming back into the engine room vent, along with some “bilgy” smell).

Dave replaced the insulation and gave me some preservation tape to seal up the air ingress points under the bed. He also cut a second intake port in the closet to make it easier to draw in inside air. The smell is totally gone now!

It’s too bad Alex and I replaced all of those parts for no reason (I liked the old blue hose better – it’s thicker). But, I’m glad we got it solved. Kudos to Trevor, Dave, and Alex (and Marcello from ITR) for getting this resolved before our vacation. I sent the old parts (still all good) back to North Pacific (but kept some spare hose).

I also love learning about the boat – and have a much better understanding of the Hydronic system, airflow, etc. We never did figure out why the wrap smelled that way. Hydronic boilers are often installed in the laz, so maybe they always smell like this but the air isn’t pulled into the cabin.

TODO: The preservation tape I used will last a year or two. If I replace it with something more substantial, it will last 4-5 years. Ultimately, I should get some door plank and screw it into the wall plywood to close off those gaps, and then caulk it for a more permanent seal.

Diesel Leak

I found about a teaspoon of diesel fuel under the site gauge on the port tank. There’s a cracked gasket on there which looks like the culprit. Since it’s on the outside of the ball valve, it should be easy to replace.

Loose Emergency Tiller Hatch

There is a round port in the swim step that allows access to the rudder assembly, so we can attach an emergency tiller, if we ever lose steerage. It came from the factory loose and sea water has been getting into the laz. There’s some rust on the rudder assembly and salt on the diamond plate. I cleaned up the hatch and tightened it down, but there’s still a little sand in there. I also didn’t use any lubricant, so the O Ring (which is really quite thin) may have gotten damaged when I tightened it.

The lazarette is filled with electronics, so it’s really important to keep it clean and dry.

TODO: (after vacation)

  1. Clean rust off the rudder assembly with FSR.
  2. Clean salt and corrosion off the diamond plate with Salt Away.
  3. Rinse and clean the deck plate and replace the O-ring. Tighten down with some lubricant. 
  4. Coat the rudder assembly with WD40.

Bubbling Dash

The material on the top of the dash in the pilothouse has some gaps beneath it, which are causing some discoloration. It looks like there is a problem with the adhesive. Fortunately, this is just cosmetic, so there’s no hurry to get it fixed. Unfortunately, it’s a fairly major job to remove this stuff and reapply it.


I got the last blinds installed in the master stateroom. They look great, but are a little awkward on the bottom (something only I will notice, I think). We weren’t able to fit blinds into either head or the kids room. They either blocked the ability of the portholes to open, or just didn’t work with the curve of the wall and the hull. For these, the XO is making some custom sunbrella covers we can pop on and off. The ones below are prototypes.


This is something that’s long overdue. We have stuff randomly scattered through the boat storage compartments without any logic behind it. There’s a lot of storage on the NP, but we’ve been totally wasting it. I brought home stuff we don’t need to keep there (the blinds that don’t fit, a sheet of extra teak, spare shelves for the refrigerator, etc.), sorted the stuff we do need to keep (dinghy spares, engine spares, tools, electronics, etc.), and started putting things in places that make sense, instead of whatever cabinet I happen to be standing next to (Binoculars at the helm!) We’re also making a bunch of small quality of life upgrades, like non-skid shelf liners, hose couplings for making the dinghy outboard flush easier, and a sun cover for the dinghy electronics.

I think we’re over the hump with the pre-trip maintenance. Now we’re moving on to provisioning. We’ll be out for 7-14 days and with the lockdowns, we’ll need to be a bit more self sufficient than usual. Really looking forward to our trip. It’s going to be a completely different experience than the Christmas Cruise on our Bayliner.