Recently, we have published two articles on lithium battery systems for voyaging boats, the first on why load dumps matter and the second on how to avoid them.
Thing is, I totally got the cart before the horse.
Before I blathered on about all that stuff, I should have taken a big step back to think and write about this exciting technology from the seamanship perspective that guides, or at least should when I don’t screw up, everything here at AAC.
So let’s do that…better late than never.
And to make it even better, let’s think about a seamanlike framework for selecting any gear, particularly stuff that’s complex, rather than just lithium batteries.
Then, after defining the problem in this article, I will share my thoughts on building a truly seamanlike lithium battery system—putting the horse firmly back in front of the cart.
Let’s do it.
#1 The Mission
When thinking in a seamanlike way, we first need to define what the mission is for the boat that we are thinking of equipping with whatever the new gear is.
After all, if we are just going to do a bit of coastal cruising in benign conditions and weather, where we can stop in a secure place with good resources any time something goes wrong, we can probably indulge our inner tech fanboy as much as we want, or at least as much as our bank manager and personal tolerance for STDW¹ will tolerate.
At the other extreme, when we are planning to take a boat into serious harm’s way, as Phyllis and I did in the high latitudes, we have to think in a seamanlike way about every detail.
The uncharted rocks, storms, and ice around the East Coast of Greenland don’t give a shit how cool the gear on our boat is. All that matters is how reliable and fault tolerant the boat is and how competent and in control the skipper and crew are.
And in between those two extremes there is the more typical coastal cruising with occasional ocean passages, which will require calibrating our thinking somewhere between the two.
That said, if we are considering making any ocean passages, it’s important to realize that at least the first few will be just as challenging as cruising to Greenland was for us after we had well over 100,000 miles of voyaging in our wakes.
Bottom line, taking a yacht across an ocean, while not particularly dangerous, at least if done right, is still committing ourselves to going into harm’s way, so having a reliable and fault-tolerant boat is still vital.
So for this exercise, let’s assume it’s today, but I’m 55 again—I’m liking where this article is going already—and Phyllis is even younger than she is now, and we are planning to take our 56-foot expedition McCurdy and Rhodes cutter back to Greenland for the sixth time, but the lead-acid batteries are at end of life and need replacing.
And then let’s vary that scenario to see how less challenging, and more common, plans affect our gear decisions.
And let’s crank a rigging option into our thinking, too, to demonstrate that this kind of seamanlike thinking can work over a wide range of gear choices, not just lithium batteries.
¹Shit That Doesn’t Work
In essence, it seems that you’ve nicely illustrated a philosophy that’s served me well over the years.
A lifetime of working in conflict or crisis zones where ‘workable system’ is akin to an oxymoronic nightmare taught me always to ask ‘what effect do I want to achieve?‘ before considering any sort of solution to any sort of issue. I always briefed my staffs the same way, permitting them to focus on the issue itself with the only constraints usually being time, money, logistics and capability. If you can articulate the ‘why’ well enough it will certainly help you come up with the most effective ‘how’.
This approach works just as well on boats with the multiplicity of systems and issues, either when just thinking of changing a routine or when considering a costly purchase – and most particularly when looking at shiny stuff at a boat show or when surrounded by the ‘good ideas’ club.
Effectively, you’re ‘cutting out the cr@p’. I think that’s why I like this site so much.
Hi Iain,
That is, I think, a very similar, but subtly different, way to look at the issue, which is great, since more ways we articulate these basic concepts, the more likely they are to be adopted. Thanks!
Hi John,
Just a very nice article with wise and useful tips and ways of thinking about going offshore safely. The following was written for another venue, but pertains to your article.
I sometimes get interested in what I think of as a meta-picture, the ripple effects if you will, and it seems to me that the shift to labor-saving devices has a largely unacknowledged ripple effect in the emphasis for the crew away from the muscular (acknowledged) and toward requiring more mental (unacknowledged). Our modern devices are not an unequivocal mixed blessing they look to be at first blush. There is a ying and yang that must be accounted for and it seems to me that these labor-savings modern gear/devices often go hand-in-hand with demanding more personal discipline: personal discipline without which disaster might occur. And where dangers were not a potential with the replaced system.
Possibly, the best example are winches and the proliferation of powered winches on new vessels and retro-fitted on older boats. Those of us with ordinary strength would have to work hard to do damage to the boat or self with conventional winches. muscle power always gives one feedback. Power winches, on the other hand, hold danger to the boat (pulling the clew out of the headsail) or worse, trapping/losing a finger in the line wraps on the winch. And it may be quite easy to work the powered winches properly and safely in everyday sailing, but when it is a midnight fire drill, and you are wet, tired and a little seasick or the crew is inexperienced and scared: mental discipline is harder to come by and forgiving, fault tolerant systems are appreciated.
I could make the same comments about in-mast furling systems as well as in boom furling (a well-set-up slab reefing system is hard to beat for ease of reefing and fault tolerance). We could go on with chart plotters and electronic navigation (just a few years ago an experienced navigator used the zoom feature of his navigation system improperly and ran aground on a race). *
In essence, I am suggesting that we trade ease of muscular effort for an increase in mental discipline and that we need to pay attention to the trade-off. It seems like, in some ways, a different sort of skill set is necessarily emerging as for these devices to mesh well with good seamanship: a mental discipline that allows these labor savings/ modern devices work safely for us: not something often talked about in the sales brochures.
My best, Dick Stevenson, s/v Alchemy
*Another example: It used to be that I mapped out any kind of tricky or low vis passage on paper, writing down the AtoNs, lights, turns, courses, distances etc. and then took this into the cockpit with me. Now I have a chart plotter under the dodger and I do far fewer of these “crib” sheets mentioned above.
Having a cockpit chart plotter is a wonderful thing and I would not go back, but I have to be more disciplined and push myself to review the courses upcoming, think about the lights I expect to see, if at night, and not succumb to “winging-it”. A couple of times I have been caught short, fog descended or things looked different in “real” life than they do on the plotter and it is always impressive how one small discrepancy or confusion can cascade into something bigger.
Or take roller furled mains: a night-time fire drill with a conventional main with slab reefing is certainly a challenge but one is unlikely to do damage or get into trouble. With roller furled mains, a hurried skipper, an inattentive new crew, a wildly slatting main are all recipes for the main becoming jammed and unable to be doused or furled and the cascading problems resulting from this.
Hi Dick,
Great comment. I agree with all of it. I particularly liked the idea that in reducing the need for physical effort we increasing the need for mental understanding and discipline. Thanks!
Great article John, and particularly valuable coming from one who we know is no Luddite!
One of the worst situations I’ve been in developed from that easiest of mistakes: letting a jib furler line slip out of my grasp. The ensuing train of events left me with a jib that couldn’t be furled and a bent extrusion that wouldn’t let it come down, inches off the rocks. It wouldn’t have happened with a hank-on sail. Yet when I think of all the times a furler has kept me off a wave-washed foredeck and saved my bacon with a quick removal of headsail leaving a clear foredeck i realize it’s a piece of gear I wouldn’t be without for shorthanded sailing: but maybe not if I were truly going in harm’s way. Eventually that sail was wrapped round the forestay, I set a jib on a removable inner stay and could sail again, but it was a continuing potential disaster until it was fixed.
An old salt at my marina told me something like this happened to them once (jammed jib furler). They ended up letting the sheets fly, and motoring in circles to let the wind wrap the jib around the forestay.
A nice trick to keep in your back pocket for next time that happens! (of course, you need to be clear of any rocks to try this…)
Nice one! Worth a try for sure.
Hi Jim,
I agree, jib furlers are an interesting trade off, just as you detail. I have always felt that from a seamanship point of view the advantages outweigh the downsides. I have written about that a couple of times:
https://www.morganscloud.com/2017/01/28/three-tips-to-make-your-cruising-boat-more-reliable/
https://www.morganscloud.com/category/rigging-sails/book-sail-handling-rigging/
But here’s a well argued opposite view:
https://www.morganscloud.com/2012/03/08/hank-on-sails/
I am just getting ready to change out my 10 year old 800 Wh system on my bestevaer 56 with a victron lithium system so this conversation is quite relevant to me. I will have a 1000 mile coastal shakedown prior to crossing the atlantic in january. I attached a schematic of the new system. feel free to poke holes! I’d also be curious within this system which spares you would carry.
I’m guessing the standalone Li battery is going to critical loads? Does the 24/12 charger allow the Pb battery and alternator to flow power into the distribution system?
Hi Jeremy,
On spares: sorry, but I just don’t have the band width to advise on individual systems, but what I would say is that if going trans-Atlantic I would carry a duplicate of every item the failure of which could bring the whole system down. That should be fairly easy to determine.
And, if it were me, I would be adding the backup I will detail in the next post on the subject.
Hi Jeremy.
I also write about spares for lithium systems here: https://www.morganscloud.com/2018/05/05/battery-options-part-1-lithium/
As an amusement ride engineer I learned the hard way that inherent reliability is inversely proportional to system complexity. We spent a lot of late night and early morning hours overcoming improvements, many of them in controls software, but to be fair mechanical and electrical equipment also contributed to the fun.
Hi William,
Now there’s a profession with no room for error! Loved the way you put it and so true: “overcoming improvements”
I love this site–it’s a continuing education program for small boat sailors. Worth every penny. Keep up the great work, John!
Hi Ben,
Thanks for the kind words, much appreciated.
Hi John,
An insignificant note first:
It’s true that lithium is not happy about charging below freezing temps. Actually it might be smart to limit the current a bit over that. Some LFP variants claim chargeability down to minus 10 C, but that’s at very low current and can easily cause shortened cell life. Same goes for high temperatures. Max 30 C is a good rule, but much higher will work fine too. However, lead acid batteries are even more sensitive to low and high temperatures. They mostly don’t really charge if far below room temperature, and at freeing temp will give a fraction of their power. If not fully charged, they will crack when freezing. Lithium gives full power even far below freezing and prefers cold storage. Both battery types are still perfectly fine for high latitudes, since they are kept inside the boat. As long as the humans inside that boat are ok, the batteries will too. 🙂
Now what I wanted to say:
An essential topic, and I agree on all points. I might be even more critical to some of the “normal ways” on modern sailboats. In-mast or in-boom furling systems are a forever no way for me. For me they have zero benefits and huge disadvantages. As I’ve mentioned in other contexts, I’m even quite critical to normal roller furling sails. (I don’t entirely condemn them). Many would conclude that I’m a gaff rig, wood and tar traditional boat type of guy, which is great. However, I’m rather the opposite. I’m a speed freak carbon fiber addict with roots in extreme racing. That’s why I trust vulnerable “comfort” installations about as much as used car salesmen.
As I’ve also discussed in other contexts, and as mentioned by others here, when making our choices we cannot expect ourselves to make rational good decisions. We have to organise for a really stupid version of ourselves. If not, that’s the version we will certainly get, at the worst possible moment. Not because of Murphys Law, but because when stressed, we think we make rational decisions, while they’re mostly emotional decisions in camouflage. That’s ok. We’re humans, not machines. We just have to organise for that fact, so we don’t bite our own behinds.
The moment that made me acknowledge the above was during a 3 day race in the English Channel in -86. We were 6 experienced sailors on a 35 foot pure racing monohull. At the time that was a big boat…. 🙂 Late at night, 30 knots pitch black and rain, flying a heavy spinnaker, surfing waves and leading the race, I was at the helm and wanted a guy to have a look on deck to make sure we were ready for a gybe in a while.
He stepped out of the cockpit, but the motion of the boat and lots of water continuously flushing the whole boat made him nervous. He went down to put on a life vest and ventured out on deck. This was a 27 year old guy, but he had 20 years of racing under his belt, 8 years ocean racing, and was totally aware of the dangers. Still, he didn’t immediately find a harness, so he “didn’t need it”. Nothing I said helped. If he went in, he would be gone, as if falling off a cliff. It went well, but…
Another example, not from myself: In the early sixties, the American car industry was in a golden age. One brand (I don’t know which, as I have this from an old marketing book) wanted to know what was the one most important factor to influence the choice when a customer made the actual decision to buy a car. Was it car configuration, practicality, number of seats, engine type, power, styling, suspension, etc? They spent a lot of money on this market research, made by psychologists and others.
The answer: The colour of the car models present in the shop that day was the biggest influence, by far. The customer could change from the intended 3 seat pickup truck to a 6 seat saloon, only because of the colour. The customer wouldn’t admit that reason to himself, of course. Rational reasons were found, to justify the purely emotional choice. The car company didn’t believe the result, so they did it again with an even more advanced scientific setup, to guide responses away from that answer. The answer remained the same. Colour. We’re totally emotional beings, living in the illusion that we mostly follow logic. Reality is that the best we can hope for is: Logic can gradually aim some of our activities in a direction we, at the time, believe is useful.
In the right situation, if we get a nudge, we can make mindbogglingly stupid decisions. The only way to avoid those decisions is to make sure we don’t experience any temptations or resistance at the wrong times. Having more advanced equipment on our boat isn’t always that type of negative influence, but in my experience it’s close to always. We need to be suspicious and think through how the equipment might influence our mind set and behaviour. When we understand that side, we need to know how functionally vulnerable it is in itself, of course, and how it might practically influence the other routines on the boat.
May point is probably clear by now: I think we should understand and adapt to the worst of our own emotional functionality. We should evaluate equipment in that context before we look at any other side of it. The boat must have no traps for our inner idiot. If somebody now quietly thinks: “I’m no emotional wuss! I’m practical. This isn’t relevant to me.” I can only say: “Good luck when reality drops by.” 🙂
Hi Stein,
So true on how irrational we really are, no matter how much we think the opposite of ourselves. As you say, we have to do everything possible to avoid that irrationality. These days, one good step, I think, to limiting our irrationality is to limit our consumption of YouTube!
Hi John and all,
For those interested in us human’s capacity for illogical decisions and our likelihood to have bias creep (or actually dominate) our thinking, there is, to my mind, no better book than Daniel Kahneman’s “Thinking Fast and Slow” (with suggestions as to think more clearly). It is easy and fascinating reading and I got a lot out of it.
My best, Dick Stevenson, s/v Alchemy
Thanks for the recomendation Dick, it’s on my reading list. After watching Kahneman talk about his book, it has moved to the top of my list! https://youtu.be/CjVQJdIrDJ0
That was a great read.
I’m pretty happy with these.
However, I’d like to suggest a #10 which is to consider the impact of the choice on the environment and others.
It seems to me that unless we actively consider the impact beyond the use on our boat we cannot progress towards a sustainable future (probably obvious, but anyway, I think this applies to everything, not just sailing).
This impact assessment would need to include:
People might also want to consider the impact on our finances (eg In Boom furling has a significant impact on our budget at purchase time but onward with servicing, repairs and later replacement.
With your examples I suggest this would add weight to the argument choosing slab reefing.
With Lithium batteries it would be a more complex balance, I’m not sure which way it would go if using Lithium while still having a diesel engine/generator (if they are used to allow an electric motor then that would move it more in their favour).
This is a brilliant article. Being of similar age to you I have more or less decided to trust the battery replacement to to lithium set up to a younger cruiser neighbour to obtain and design new electrical system. I am in Fiji which presents challenges. One can either make the right decision, wrong decision or no decision.
Hi Ian,
Thanks for the kind words.
One suggestion for you, while it’s fine to take advice from a more techie cruiser on systems like lithium batteries I think it’s really vital, from a seamanship point of view, to have a good overall understanding of the system and how to manage it when stuff goes wrong, as it inevitably will.
So, if you decide you don’t want to dig into how lithium systems work—not a thing wrong with that—and how to trouble shoot them it would be better to stick with lead acid which is at least an order of magnitude easier to understand and trouble shoot.
I write more about that trade off here, although about marine electronics: https://www.morganscloud.com/2016/01/08/marine-electronics-system-recommendations/
And more about lithium here: https://www.morganscloud.com/2018/05/05/battery-options-part-1-lithium/
I have been considering the idea of having two battery systems. Well, three, if you count the engine batteries. The critical systems would be traditional and the reefer-watermaker-type stuff would be lithium. Obviously you buy complexity, but what you get is the advantages of both systems, and you are a couple of switches away from complete redundancy. I’m sure that this is a stupid idea, but I’m just not sure why. Please turn me to the light.
Hi Ashley,
Not stupid at all. I will be publishing my solution early next week.