Options 1 to 3
So far in this series of chapters we have covered BMS requirements, balancing and monitoring, choosing voltage and peak current (amps), and fusing, so, in conjunction with other chapters in the Online Book, we have the tech stuff done.
Phew. Just thinking about all the stuff we need to know to install a good lithium system on an offshore boat makes me tired.
Anyway, let’s dig into the actual buy:
- Should we just pull out the credit card and get others to do the whole job, or do it ourselves?
- And if DIY, how far should we go with that?
There are nine different configurations to consider, so I have split this into two to keep it manageable.
In this chapter let’s examine the costs of the first three, fully integrated high-end systems, primarily from one manufacturer, so we can be sure everything will communicate and all charging sources can be properly controlled by the battery BMS:
Key points I’d like to emphasize once again here:
Hi Matt,
Good point on the cell cost not being what matters to the overall cost. This is particularly true with Victron’s recent battery price drop. I’m planning to explore that more in the next article.
is it necessary to replace an engine alternator used for wet cell when converting to lithium ?
Not necessarily, but you will not get the full benefits (and value for money) of your investment in lithium batteries unless you have an alternator capable of exploiting their high charge acceptance rate. There’s a lot more detail on this in the other chapters of this online book.
Hi Mike,
If it is the stock alternator that came with the engine, yes it will need replacing, as will the alternator regulator.
Virtually every new build project I’m currently working on (I’m in Taiwan as I write this inspecting three new builds, all lithium), and have worked on in the past three years, is equipped with LFP batteries, up to 96 feet. I’ve used Lithionics, MG, MV and Victron, and by far the greatest risk, in my view, isn’t the batteries themselves. Rather, it’s the installation/wiring and specifically wiring errors and faults. These are the same wiring faults I’ve been encountering for decades, however, the difference is LFP batteries and charging stresses the electrical system in ways it’s never before been stressed. Therefore, what was a minor fault in the days of AGM, now becomes a potential fire in the LFP world. Here’s are two common examples, one, heat shrink on cable ends impinging on the contact surface, in some cases reducing it by 90%, with consequent overloading of that contact surface and heat generation. Two, ring terminals that are not installed in order of ampacity, i.e., largest to smallest, particularly in high current scenarios. This causes high current to pass through the small ring terminal, which can exceed its ampacity, which in turn causes heating, and expansion, and that cycle causes the connection to loosen, and arc, and you have a potential fire. That will result in heat generation, a lot of it and quickly. Therefore, the onus is on installers more than ever, to practice good, meticulous and ABYC compliant wiring techniques.
Hi Steve,
Welcome back, good to hear from you again. And yes, I totally agree. In an earlier chapter in this guide I looked at the issues of high current: https://www.morganscloud.com/2024/03/21/lithium-battery-buyers-guide-part-4-fusing/
I also wrote this tip in the same vein: https://www.morganscloud.com/jhhtips/no-lithium-batteries-dont-burn-boats/
And more yet here: https://www.morganscloud.com/2022/03/19/8-checks-to-stop-our-dc-electrical-system-from-burning-our-boat/
All that said, as you point out, poor practice can cause a fire even if all of the above articles are followed to the letter. The devil really is in the details.
Hi John,
On hours needed for DIY on any stage of this, I think your hours estimates may be correct for the time it takes to do the actual job, but including the pondering about how to do it, and the buying of the right tools, the postponing due to worrying about what to do, and so on, I think the time estimate can be multiplied with a significant number. I work with this type of stuff and have the tools and much of the knowledge, but mostly others do the hands on. The hands on guys work 4 times as fast as me, at least, when looking at the whole job. Perhaps mainly because they remove the gaps of no productivity between each task.
Spending 4 times, or 20 times as long on getting something finished, means it’s really hard to justify doing it yourself. I sometimes ask people restoring boats how much money they think is the minimum they would accept per hour for the work they’re doing. If say a meagre 10 Euros/Dollars is the answer, the boat value really needs to increase by each hour spent to justify doing it ourselves. 1 000 hours is 10 000 Euros/Dollars we need to get paid in increased boat sales price. Especially high tech work, like the stuff discussed here, is perhaps not possible to justify DIYing, unless we have no other way to spend our time, making more than 10 Euros/Dollars an hour.
Interestingly, Victron Energy, MG Energy and Mastervolt are originally all from the Netherlands. The two first are still based there, but much of the actual production is in other countries, of course. I don’t know the history behind this, but MG seems very much like a smaller brother of Victron, and Victron may could perhaps be made as an improvement of the previously very closed systems of Mastervolt? Just speculations.
Hi Stein,
I figured about double the time for DIY, but you may easily be right that four times would be closer to the mark if we add in all the research time. I seem to remember I had at least 30 hours in designing the simple lead acid system for our J/109.
Very, very useful information, thanks.
where you are striking a raw nerve: the individual pieces aren’t soooo expensive it by the time you add it all up, the total blows you away …
at which point you might as well buy top of the line because doing the hours and small items make the majority of the project. In a way like there is no sense buying cheap tools …
we did quite a few comparisons, and everything Mastervolt sells turned out be quite a bit more expensive, last time we tried. They claimed some superiority in the converter chargers, that I didn’t quite get.
there is also Sterling Power from the UK, who appear to have really good kit and competitively priced.
Am I correct that this is a secondary alternator and you leave the one for the engine alone?
Hi George,
Thanks for the information on Mastervolt.
As to the alternator, I’m not a fan of adding a second alternator but rather recommend replacing the original OEM: https://www.morganscloud.com/2013/11/06/10-tips-to-buy-and-install-a-liveaboards-alternator/
On a small system all with the same voltage, I would agree. With a 24V house system, I’d rather keep it completely separately. But I can see the 24/12 transformer as a really good compromise.
Your final number is eerily close to the cost of a newly installed engine. A big ticket item which will probably require a degree of fettling. Something that might make sense to consider on a new build.
This subject is a source of endless interest to us readers but how much it contributes to the gaiety of nations I don’t know. Is the complexity and potential for time wasting setbacks in out of the way places really going to contribute positively to the experience of voyaging ?
To me the great benefit of these kinds of articles is to make one think more deeply than normal about what really matters on a far foreign boat. “Get thee behind me sexy new kit.” Perhaps this kind of innovation is best left to those who do their sailing in the first world – nothing wrong with that.
well, if you take all the plastic in a boat, the difficulty of recycling it and the fact the most boats are unused for 11 months of the year, gaiety of nations isn’t something that would come to mind in this context. any way you try to justify it, it is a luxury item and if things work out, it will help your gaiety and that of your crew but thats it.
furthermore, the cost of a raw engine compared to the overall cost, is, sadly, not very much.
is it needed? theoretically no; just as you can go hiking into the high mountains with 20 kg of kit. If that spartan style makes you, and more importantly, your spouse happy, cool. If you can still do it age-wise, also cool. i did it 20 years ago, I don’t think it would be my way of hiking any more. Hence, if not (that is after a while), then perhaps those 16K are a really good investment.
Or if it means being able to work from your boat.
and in the supposedly first (soon to be fourth world considering the actions of the political personnel) world with a plug in marine at every corner, it is much easier to go with little than in other areas without those comforts. So this kind of innovation is perhaps much more relevant anywhere but the first (soon to be fourth) world.
As an example, I had a long conversation with a fellow who spent last summer in Svalbard and was happily going through just on solar panels and a good installation. Said he didn’t start the gen set a single time and had all the power he needed (with a diesel cooker and a refleks, so less demand).
Hi Mark,
A very wise comment. While I can see the benefits of a lithium upgrade I would not have bothered if we had kept the McCurdy and Rhodes 56. Just not worth the money and aggravation given that we already had a good lead acid system. Rather I would have just added a couple of solar panels and called it good. Also I can think of many other things I would have spent $20,000 on way ahead of a lithium upgrade and that on a boat already well tricked out.
I am totally happy with the *tiny* lead-acid bank on my current sailboat. I wouldn’t even dream of converting it to lithium.
At the same time, I have a boat on the drawing board (and partly-built in the shop) that may well end up with 5 kW of solar panels and 40 kWh of lithium batteries, and no fuels, on board. (It’s spec’d for 100% solar electric propulsion.)
Horses for courses. There is no one-size-fits-all solution. The important thing is that you pick a system that fits your own needs and priorities, and then do a good workmanlike code-compliant implementation of whatever you pick.
your last paragraph is spot on
Hi Matt,
Word!
And I have to mention that John has said similar things on most topics here. Lithium is just another of the innumerable questions of this kind that we have to struggle with. “It depends…”
I’ve long held the belief that if you ask a good professional a good question, the answer will invariably be “it depends.” 🙂
Hi Nathan,
I totally agree. “Experts” who are certain about everything make me nervous.
Spot on, Matt. There is no perfect solution, but careful installation of whatever system you run is a necessity.
Hi John
These articles are fantastic and timely. Thank you.
I’m trying to wrap my head around all of your advice so I can make some high level informed decisions.
In my particular case I have 3 battery banks – domestic, engine & bow thruster all 12v. Main power users – fridge (12v or 24v), freezer (12v or 24v), bow thruster (12v), electric winch (12v), lofrans windlass (12v), 2 toilets. Domestic lighting can be 12v or 24v.
I have 3x 160AH AGMs for the domestic maybe nearing the end of their life (9 years old) and probably not big enough now me and my wife will move on full time. Keeping her supplied with lots of power and fresh water is priceless if we can go cruising!
Points I am pondering…
In the high end lithium article you suggest to consider 24v and have priced the lithium and AGM accordingly but this, if I have understood correctly, differs slightly to the ’12v or 24v’ articles. Here you suggest not to consider 24v if you are already set up with 12v.
Is it seamenlike to use eg Victron Orion to power some critical stuff inc NMEA and do without a 12v battery if converting to 24v? Is an Orion as reliable as an AGM battery?
When converting to lithium you must have a lead acid bank for the critical stuff. Why not have 24v domestic and 12v critical?
Space is not an issue on my multihull, but weight is, so adding batteries in the short term would be possible.
Therefore Im wondering if 24v domestic with 12v critical would be good decision and allow me to do this project over a period of time?
Ie 1st step would be new lithium to power the fridge, freezer, inverter and watermaker to keep my wife smiling. Leave the 12v in place and I gradually move non essential things over etc eventually removing 2x AGMs.
Any comments gratefully appreciated.
Thanks
Richard
PS I’m checking almost daily for the next lithium articles!
Hi Richard,
24 Volts is great, but, as I say in both articles, it’s expensive and a PITA to upgrade to. So there is no right or wrong here, it just comes down to whether or not you want to spend the time and money to make the change. That’s a long way of saying, “that’s up to you”. I have laid out what the tradeoffs are so that’s the place to start, but only you can decide if it’s worth it.
Would I change? I never did on the McCurdy and Rhodes 56. But then I probably wouldn’t have changed to lithium ether, at least not yet. But then I had a lead acid system that was doing a great job and on a boat that is not weight sensitive.
Loved the article and the comments.
A note to readers who are based in Australia: a commercial operator and friend mentioned to me a couple of weeks ago that AMSA (Australian Maritime Safety Authority) will not ‘survey-certify’ any commercial vessel that has a Lithium chemistry system on board; he had installed an Li-based system on his in-survey vessel, and had his re-certification knocked back. He replaced a $13,000 system (LiFePO4) with AGM batteries, and the certification was granted immediately.
Clearly there is a lag between best-practice and what-the-certifying-body-will-accept, at least now.
Hi Kit,
Thanks for the heads up on that, sobering indeed. Andy Schell got a lot of push back in England about lithium too. In the end, after much debate, the classing authority allowed it, but only with a lead acid serial backup as we recommend.
I will contact that skipper and ask if he had suggested this option (lead acid serial backup). I am guessing not as he is not a particularly ‘technical’ guy. Your approach is a genuine systems one, one that reduces risk and maximises rewards, IMHO. Excellent article, thanks.
Hi Kit,
Thanks for the kind words. Yes, it would be interesting to know if that would satisfy the authority. It should, but then again these inspectors are notoriously conservative, with good reason, so who knows.
Thanks for the response appreciated!
How would the NMEA in the high end system priced above be powered? With a DC to DC charger as the power source?
Hi Richard,
That would be the best way. I did not put it in since that’s intrinsic to any 24 Volt system so not really a cost of upgrading to lithium. Do note that if you plan not to have a 12 Volt battery, it’s important to use a DC/DC power supply, not just a DC/DC charger. The two are different, although many (maybe all) the offerings from Victron can be both.
What about lightning? My 38′ Morgan was struck and I lost all electrical and electronics, presumably from induced currents. That was $15K worth of stuff (she had lead-acid batteries). I haven’t seen any mention of potential problems to lithium-based systems, and ways to mitigate them. That’s a lot of money to fry, at best, and potentially catastrophic if a BMS fails, at worst. Lightning is a real concern to us Florida sailors.
Hi Oscar,
That’s a good point. If we have an expensive lithium battery system the loss in a lightning strike will be higher and the chances of damage higher too given that lead acid batteries don’t have any directly associated electronics.
I don’t know of any amelioration measures that are specific to lithium and would be surprised if there are any. So I think lightning strike risk is just another thing to think about when making the decision between lead acid and lithium.
Some years ago Matt wrote an article about lightning strike protection: https://www.morganscloud.com/2014/02/23/protecting-against-lightning-strikes/