The Offshore Voyaging Reference Site
Tips, Tricks & Thoughts:
We are all aware that in yacht use the Achilles Heel of lead-acid batteries is that only about 50%1 of the rated capacity can be used on a daily basis.
But now Trojan, a well-respected brand, have released their AES AGM Battery with a claimed life of 1200 cycles to 100% discharge. These batteries are also purported to be able to withstand being left in a partial state of charge for long periods, repeatedly.
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Well, that was quick. It was just last week that I shared that the WS500 Pro was on time, and today what should turn up here at AAC World Headquarters, but a fully functioning production unit.
Al put on his red suit and slipped down the chimney to put it under the tree…wait, that’s not for four months, so I guess it was Fedex.
Anyway, thank you Al and Dragon Fly Energy for the evaluation unit.
Of course, being a cool calm guy who never gets excited by new technology, I put it aside and might get around to installing it six months from now…not.
The reality was that I had it out of the box and my iPhone connected to it within 10 minutes1—yes, it’s that easy.
And that highlights one of the features I like the best on the original WS500 and the Pro: both can be powered up on the bench so we can program them before installing on the boat.
As you can see, the Pro is being powered by a standard USB cable using an old Kindle wall wart, and my phone is connected to it via Bluetooth and showing the regulator monitoring screen.
See this Tip for why that’s a way cooler feature than you might think, as well as more information about the Pro.
I also verified that I can fully program the regulator from my iPhone over BlueTooth2.
By the way: the Pro automatically detects that it’s being powered by USB, instead of the harness, and so does not throw an error because there is no battery or alternator connected, like the WS500 does3.
Before I close, one other cool feature of the Pro I have not mentioned before:
The first time we connect a phone to a new Pro it insists we change its password before it will let us change any parameters.
Smart…do you want your brother-in-law playing with the configuration? Or maybe some super-smart but vindictive 14-year-old on the boat next door?
But wait, what happens if you forget the password, or maybe buy a boat with a Pro already installed? Not a worry, if we connect directly to the unit using the USB cable we can reset the password4.
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Late September
In April I hinted about a Bluetooth-enabled version of the WS500, our favourite alternator regulator, and in late June I confirmed that the WS 500 Pro had been announced, for shipment in “fall of 2024”.
That said, I always worry that products announced before they are ready to ship will be late, often horribly.
Anyway, the good news is that Al Thomason, designer of the WS500 and Pro, tells me that the new unit is on time:
And further good news, I just received a notification that the Wakespeed app updated for Bluetooth is ready for early access testing on Android and iPhone (I’m on the Beta test list).
And if you just can’t wait to play with a WS500 Pro, Al himself will be at the Port Townsend Wooden Boat Festival with a bunch of fully powered-up units during the first week of September.
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As I have written before, (needs updating) most shore power chargers are far less smart than they claim to be.
The problem is that unless chargers are connected to and compatible with monitoring systems like Victron Cerbo with Distributed Voltage and Current Control (DVCC) enabled, or Victron BMV with VE Smart Networking, they have no way to know when a lead-acid (or lithium) battery is fully charged, which requires measuring the charge current into the battery, exclusive of loads, (amps not volts), using a shunt1.
To get around this most shore power charger default programs tend to drop out of acceptance (typically 14.4 volts2) way before a lead-acid battery is properly charged and that can lead to sulphating and reduced life.
So what’s the answer? Well that depends on how we use our boat and the charger, but here are a couple of examples:
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As we hinted a few months ago, Wakespeed have announced a new alternator regulator, the WS500 Pro.
Here’s the scoop based on an in-depth email conversation I had with Al Thomason, chief designer at Wakespeed.
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Do you know why so-called “fail-safe” ABYC Galvanic Isolators are much more expensive than the Galvanic Isolators that are still allowed here in Europe?
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I’m not sure how many times over the years I have beaten some variation of this drum here at AAC. Here and here come to mind, but I’m sure I have written it, or something like it, many more times.
And yet, when a new cool piece of gear comes out, what do we all often do, me included, but get all excited about all the awards it’s won and its cool new features and run right out and buy it.
Hell, I have done this more than once:
Let me see if I can be gentle about this…that’s a really stupid thing to do.
Oops…I guess I kinda failed the gentle test on that one. The good news for me is that, unlike with full articles, my editor does not see Tips before they are published!
Whatever, here’s why buying newly released products, particularly electronics, is…unwise:
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I recently received a link to this forum thread on lithium batteries that includes a concerning quote:
Another note, during installation, there is a yellow and black wire on the Zeus alternator harness, “ALT GND” which is for a ground of the Zeus to the Alternator.
In some installations, this has caused a ground loop, so we are advising to not connect this wire during installation and simply tuck it away.
This is a serious smoking gun. Designing any electronic device with two grounded lines—connection to the negative in the case of boats—is poor practice and, further, being advised not to connect a wire that was provided for in the design is an indication of potential problems that will, I’m guessing, only get fixed with a hardware redesign of the Zeus.
Read on for why.
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The above is a graph of battery voltage on our J/109, currently still out of the water but uncovered.
As you can see, each day shortly after dawn our solar panel starts charging and since, other than the first day when I was aboard and using power, there are no significant loads and the batteries are fully charged, the voltage rises rapidly to ~14.4 (temperature dependant): acceptance for our AGM lead-acid batteries.
And, after a predetermined time, and because the batteries were full anyway, our solar regulator drops the charge voltage a bit, and then at dusk it shuts down.
This is absolutely wonderful for lead-acid batteries because that chemistry is:
We might even say that solar makes lead-acid batteries wonderful again.
But this same pattern would shorten the life of lithium batteries because:
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In this Tip I’m building on the last Tip in which I concluded that huge battery capacity makes little sense for most usage profiles.
It’s tempting when replacing a lead-acid bank with lithium to simply default to installing all the lithium capacity that will fit where the lead-acid batteries were. And indeed that might make sense if the boat had far too little battery capacity in the first place.
But defaulting to that strategy without doing a bit of basic math could cause us to not only spend way more money than we need to, but also to forgo a wonderful benefit of lithium batteries.
Here are a couple of rules of thumb that will help when deciding how much lithium capacity we should install in place of lead acid:
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I’m working on the second part of the Adventure 40 electrical system specification.
One of the fun things about this project is that since we are starting with a blank page, rather than upgrading an existing boat, which I often write about, design fundamentals become more apparent.
Here’s one that just came to mind:
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I’m on the Beta test list for software Upgrades to the WakeSpeed WS 500 alternator regulator.
Not because I like testing new software—only marginally more fun than having a root canal, in my view—but because I’m a huge fan of the regulator and firmly believe it’s currently by far the best option for charging most battery banks on offshore yachts, both lead acid and lithium, and so I like to keep up with what my friend-over-the-phone and chief-of-all-things-technical at Wakespeed, Al Thomason, has been cooking up.
The latest release announced that the WakeSpeed will now work with Victron Distribution Voltage and Current Control (DVCC). This matters a lot more than it might appear to at first glance:
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One of the things I love about my job is that, despite having maintained and refitted boats for over 50 years, I’m still learning, often as the result of the discussions we have in the comments.
This has certainly been the case here as I think about reducing short-out risk on batteries, particularly lithium. One realization leads to another.
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The great discussion on my recent article about proper battery fusing and particularly the potential danger of MRBF fuses failing closed, instead of opening the circuit in the event of a short circuit, reminded me about another big downside of these kinds of fuses that actually negates the supposed advantage of being able to install them on the battery terminal.
Take a look at the graphic above. As you can see, the fuse comes with a little rubber cap that I bet is there to satisfy the ABYC requirement to insulate all battery positive terminals from possible shorts.
First off, having used these fuses on the small lead-acid bank on our J/109, I can tell you that little cap is pretty useless. It refuses to stay in place and does not properly cover the exposed parts of the battery lug.
Wait, it gets worse: The other problem is how the heck can we insulate the metal part that bolts to the battery terminal?
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There are now battery vendors advertising drop-in lithium batteries rated for engine starting.
If ever there was a solution looking for a problem, this has gotta be it.
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I have been deep into researching lithium batteries, and particularly how they charge, while writing new buyer’s guide chapters for our Electrical Systems Online Book.
One of the best sources I have read is a post by Eric Bretscher, over at Nordkyn Design.
Before you go read it, a few thoughts:
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Scuttlebutt have an interesting two-part story about upgrading the electrical system in a J/105. Worth a read, even though this is a racing boat.
To me the takeaways are:
All useful, but the biggest takeaways are:
Much more on electrical system upgrades:
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Anytime I write about batteries and charging someone is bound to bring up one of the clever gadgets that fool a stock alternator into charging at a higher current for longer without resorting to external regulation.
Some of these gadgets, particularly the VRC-200 from Nordkyn Electronics, are undoubtedly very clever—here’s another one I wrote about.
And I can certainly see using one of these as a quick and relatively inexpensive way to make the stock alternator charging a small battery bank on a boat used for weekends, and perhaps the occasional week cruise, charge more quickly and efficiently.
But for an offshore voyaging live-aboard boat, these things are not a good idea.
Most alternators that come with our engines will not last long if pushed hard day in day out, particularly if trying to charge a large bank (lithium or lead-acid)—stock alternators are simply not designed for that kind of duty cycle.
That said, the Nordkyn will extend alternator life by monitoring its temperature, but that’s going to mean that most of the time the alternator will not be putting out much because stock OEM alternators heat very quickly as soon as they come under load.
Of course you could use the Nordkyn with a heavy duty alternator, which would be a good combo.
But my thinking always has been, and remains, if we are going to the trouble of installing a high-capacity bank, we might as well do the charging right with a rugged alternator designed for the job, installed right, and with an external regulator that won’t be subjected to the heat inside the alternator.
And then if we are going to do the alternator right, we might as well go the whole hog and do the regulator right too.
By the way, Victron have a fun demo showing how fast they can burn out an alternator when charging lithium batteries. There’s a lot of good stuff to learn here, particularly the counterintuitive fact that low engine RPM will do more damage.
That said, we offshore boat owners should understand that even a big lead-acid bank can fry alternators too—our 800 Ah at 12 volts (9 kWh) AGM lead-acid battery bank on the McCurdy and Rhodes would happily lap up 250 amps for an hour, at least, if we had had an alternator that big, and regularly sucked 150 amps for two hours out of the alternator we did have.
Anyway, have a watch, it’s interesting:
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In the last few weeks I have been getting a series of emails from Battle Borne aggressively promoting sale pricing on their lithium batteries, see the above.
As far as I can see, these are batteries that don’t have any way to communicate with external charging sources or even a way to inform you that they are about to load-dump and turn your lights out.
In our opinion, this type of battery is:
And further, our advice is that only batteries that can communicate through CANbuss (wires), not Wi-Fi or Bluetooth, with charging sources and monitoring systems should be used on boats, particularly offshore boats.
Much more here:
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A few weeks ago I wrote an article on renewables in which I opined that the days of wind generators are, for most cruising usage profiles, over. Too much windage, too much noise, in return for less generated electricity, particularly when it matters, than many people believe.
The interesting thing is I got surprising little pushback.
Anyway, here’s another reason to think seriously before installing a wind generator: the things can be seriously dangerous, as this cruiser found out the hard way.
So if you do decide to install a wind generator:
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I’m as concerned about climate change as anyone, and maybe more than most, but obfuscation and pretengineering does not help us get to a sustainable future.
A good example is the way that electric-drive vendors use horsepower when talking about the diesel engine they want to replace and kilowatts when talking about their offerings.
You see, horsepower and watts measure the same thing: power.
1HP=.7457kW
It’s that simple,
I was triggered to write this by an electric-drive company claiming that installing their serial-hybrid drive—diesel generator driving an electric motor—in a long thin efficient motorboat would save 30% in fuel burn over the standard diesel engine that comes with the boat.
But here’s the smoking gun, they promised 8.5 knots top speed with the generator driving the electric motor, but with the standard diesel that boat can do 18 knots and cruises efficiently at 10.
Yup, all they have done is decrease the power, probably by more than half. Of course that will save fuel.
But here’s the thing, in most usage profiles for cruising boats, simply putting in a right-sized diesel engine and settling for say 9 knots cruise and about 11 knots wide open—still faster than the electric—instead of 18, would almost certainly save more fuel as well as costing way less (think less than half), and weighing less, than an electric motor, generator, and a huge lithium battery bank.
The latter to run silent for an hour or so…and then have to be charged with…the diesel generator, in most cases.
Wait, it gets worse, weight is a killer on a boat like this, making the hybrid setup an even sillier idea since it will weigh way more than the right-sized diesel and so make her even less fuel efficient and take up more space.
What fevered mind came up with the idea that burning diesel to create rotation (generator engine), and then turning that into electricity (generator alternator), and then turning that back into rotation (electric motor), is more efficient than burning diesel to make rotation (diesel engine) in the first place—conversion losses are a bitch (they compound)—one conversion always beats three.
Sure, electric is great, as long as we stay close to a source of renewable produced power, but staying close to the dock is not what people will use this boat for—and no, a practical amount of solar panels are not going to help much.
Which brings us a full circle.
It’s always a danger signal when a sales person talks HP one moment and kW the next. They are probably trying to hide something, and now you know what that is.
And no, there is nothing magical about a horsepower or a watt just because it was produced by an electric motor. The whole torque thing is most-all BS too when applied to cruising boats—great though if you want to get a heavy train moving from a standing start.
More about all this here, including a very cool calculator, which will let you see if your usage profile will benefit from an electric drive. It’s a bit out of date but the basic physics does not change…conversion losses are a bitch…wait, I already said that.
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There has been a lot of excitement recently about the release of a new alternator regulator that takes direct aim at the WakeSpeed WS500‘s position as the only truly smart regulator, primarily because it measures the current (amperage) that goes into the battery and then acts on that information, rather than making a bunch of guesses about the state of the battery that are usually more wrong than right, like, for example, the regulators from Balmar—I explain all this in more detail here and here.
The new regulator is the Zeus from ARCO, and both Panbo and Rod Collins, who advised during the development, are pretty excited—I recommend that you read Rod’s article for an insider’s view on how this new regulator came to be.
I’m super excited too since the new regulator fixes a problem that I have been beating on Al Thomason, inventor of the WakeSpeed, about since the WS500 came out: no easy way to program it and see what it’s doing over Bluetooth—Al and I seem to chat every six months or so about one thing and another and I’m sure he is getting sick of hearing it!
And the Zeus seems to be easier to install and program in a bunch of other ways; for example, the harness it comes with will work with both N- and P-type alternators.
But here’s the thing.
I know from our chats that since the WS500 was released, much, possibly most, of Al’s energies and smarts, which are prodigious, have gone into making his regulator work seamlessly, mostly over CAN bus, with the ever more sophisticated lithium battery management systems from companies like Lithionics and Victron, as well as many others.
Here’s an example of how tightly Al has integrated the WS500 with Victron’s products, including their system monitors.
We are talking close cooperation here. For example, in a multi-BMS multi-battery Lithionics setup, if one of the BMSs goes offline, the WS500 will know that and automatically adjust its charging profile accordingly.
The point I’m making is that it’s all very well for ARCO to claim that they have all this cracked on day one, and much more besides, but is that real when one of the smartest engineers in the business has a five-year lead on them?
And process control programming and communication, which is what this is, is an iterative process of try, debug, try again, debug…
And further, keep in mind that with this stuff one bad bug could take out thousands, or even tens of thousands, of dollars worth of equipment in the blink of an eye, or render your system down until sorted out.
And one of the things that I know Al has focused on, because he’s a deeply experienced process control engineer, is failsafe, so if his regulator ever gets confused about what’s going on it defaults to shutting things down, or at least switching to less potentially damaging charge parameters.
This is actually one of the reasons it can be a bit frustrating to get the WS500 working the way we want it to. The default configurations are very conservative.
So sure, if you have a nice simple and robust lead-acid battery-based electrical system, give the Zeus a try, if you wish.
But if you have, or are contemplating, installing a sophisticated lithium battery-based system, I suggest sticking with the WakeSpeed WS500 for a while while ARCO make the almost inevitable early-days mistakes on someone else’s boat. And also until the manufacturer of your battery and BMS tell you they are 100% happy seeing their batteries charged by the Zeus.
And one final thought. The Zeus page claims to make it super easy to change parameters with your phone. Sure that’s cool, but with ease of change comes the temptation to play around indiscriminately and changes can lead to big problems, so be careful.
All that said, don’t get me wrong, I’m still super-happy to see a competitor to the WakeSpeed WS500—bet we see that Bluetooth capability I have been bitching about for four years real soon.
I like Al Thomason and he has been good to me by tirelessly sharing his smarts in phone calls and emails.
On the other hand, I’m on record as more than a little sceptical about Firefly/Battle Born, the company that bought WakeSpeed, so I think those two kinda cancel out.
You should also be aware that Al has arranged for AAC to get two WS500 regulators for free, one of the early ones (now working on our J/109), and a month ago, one of the newer ones with a NEMA 2000 output that I will install this winter and play with next summer.
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Every so often, someone sends me a link to this article, originally published in Professional Boat Builder and repeated at Sailing Anarchy, that starts with the line:
Lithium-ion batteries start fires.
First off, the author does not differentiate between lithium cobalt oxide (the battery type in your phone) and lithium iron phosphate (LiFePO), the chemistry generally used for service batteries on boats, which is much safer and less volatile.
In fact, recently, ABYC tried to set one of the latter types on fire and had no luck.
Second, he goes on to say that a large number of boat fires are caused by batteries.
I don’t think that’s true.
What I would agree to is that a large percentage of fires on boats are caused by poorly designed and installed electrical systems, and that includes those installed by the “professionals”:
The electrical system on our new-to-us J/109, as installed by the builder in 2004, was a fire looking for a place to happen, mainly because of inadequate fusing.
And then in the years after she was built and before we bought the boat and rebuilt the electrical system, “professionals” had made the fire risk far worse with stupid changes and additions.
This is a distressingly common situation, and don’t make the mistake of thinking that just because your boat has passed survey that the electrical system is safe. Ours did and wasn’t.
And don’t get me started on the dangers of electrical systems designed and installed by boat owners who watch a few YouTube videos, source lithium cells from some vendor on eBay, and have at it.
So to me, the correct statement is:
Lithium batteries don’t burn boats, poor battery and electrical installations burn boats, regardless of battery chemistry.
Me
I have written a lot more about this in this Online Book, including how to decide if lithium batteries are right for your boat:
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We were on the boat for a couple of days last weekend and one evening I decided to check email and the weather on my iPad.
But when I picked it up, it turned out I had forgotten to charge it—it was as dead as John Cleese’s parrot.
Not a problem, we have a USB charging port on the boat and a USB C (it’s a newish iPad) cable.
I plugged in the iPad and, since this had reminded me, my iPhone 13, then at about 50% charge, into a different port.
The photo at the top of the Tip shows the total current draw before plugging in these devices:
The photo below shows current with both devices charging, and no other changes.
Yikes, these two handheld devices are drawing 3.5 amps at 12 volts, or 160% of what it takes to power a small boat at anchor at night.
Yes, I know, in a couple of hours or so both devices will be fully charged and only require a trickle of amps to keep them there.
Still, suppose Phyllis charged her iPad and iPhone, too, and then maybe we have guests with devices, and then there’s the iPad we use for navigation. And many boats have one or two laptops…
It’s stuff like this, albeit not by itself, but added to other sneaky users of amps, that push cruisers into expensive electrical system upgrades including: excessive arrays of solar panels and/or the clutter, noise, and weight of wind turbines; or a generator.
Worth thinking about.
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We fitted a MarineBeam LED Steaming/Deck Light on the mast on our J/109 a year ago, and so far I’m impressed.
Small, light, relatively inexpensive, and amazingly bright, with incredibly low current draw.
Of course we don’t know how reliable it will be over time, but so far so good.
By the way, I have never used deck lights at sea. Too dazzling and disorienting, and, worst of all, our own bodies throw shadows just where we want to see. Much prefer, and recommend, head lamps.
The primary reason we have a deck light is to reduce the risk of someone running into us because they did not look up and see our masthead anchor light. Yes, it happens.
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