The Offshore Voyaging Reference Site

Living In A 12-Volt World

When we built Pèlerin we were determined to stick to the KISS principle—Keep It Simple Stupid. That included our determination to keep her a 12-Volt boat. We didn’t want the cost, weight and complication of a built-in generator, although this did cut us off from some things that we would have liked such as a microwave.

But you can’t have everything, and in our view we have an acceptable compromise, and I can assure you we don’t lead a hair shirt existence on board. And please bear in mind that ours is a live aboard boat—we have to live with the consequences of our choices every day. We have chosen our way of life—others may differ…

Start Right

We started by building in a big battery bank (6 x 95 = 570ah) of only good quality lead/acid batteries. We replaced these during 2013 in Brazil, after 5 years of constant use living aboard, and even then they weren’t dead, just past their best. And we hardly ever run the engine to charge the batteries, and motor as little as possible when on passage as I’m almost allergic to it after so many years of working on boats where you spend an inordinate amount of time motoring to keep to deadlines.

Renewable Energy

We invested in solar and wind, a powerful alternator (110 amp) on the main engine, and a back-up petrol generator for emergency use. This set-up has never failed us, although on passage we are short of charging power when the wind goes aft of the beam and our wind generator slows down as a result. This is particularly true at night, when we have navigation lights and instruments on and the solar panels are of no use.

The NAPS solar panels (90 w total) on the arch can be articulated and continue to work well, but the two 45 W Sunware semi-flexible panels that we glued to the deck had begun to delaminate before our Atlantic crossing to Brazil in 2012, and have now both been consigned to the dumpster.

Not good when you consider that they were less than five years old when they began to fail, had been mounted in a sheltered position where they were unlikely to be damaged, and cost nearly £1000 (US $1500) for the pair.

At the moment we haven’t decided what we shall replace them with, although we like the look of the high output Solbian SP panels, but we’re naturally wary after our less than stellar experience with the Sunware flexible panels. But we certainly miss their output, and have a noticeable shortfall in their absence.

The wind generator we installed was the Superwind, a choice we’ve never regretted. After changing the blades to the factory upgraded ‘silent’ models, it’s been a quiet, powerful and utterly reliable unit, definitely one of the best pieces of equipment on the boat.

During our Atlantic crossing we were close reaching for nearly a week in the SE trades and never ran the engine once thanks to the Superwind that did most of the work of charging the batteries with only a little help from the solar panels. We were even able to make water from wind—that’s performance worth having.

12 Volt Watermakers

Our determination to stay with 12 volts also dictated the choice of watermaker, and we installed an absolutely basic Spectra Ventura 150, a model that has no electrical complication, bar the feed pump. This has performed flawlessly until this year, when one of the O rings that seal the check valves cracked and developed a leak.

We carry a complete spares kit with all O rings, etc., but I checked with Spectra and they steered me to the very helpful people at Watermaker Services (as we were in Antigua), who confirmed my diagnosis and told me that there were now improved Viton O rings available and sorted me out with a full set at little expense.

As we installed the watermaker ourselves in our aft services cabin so that we can get to it easily, two hours later it was out, repaired, reinstalled and running again. But I suspect that once one set of O rings goes, others will soon follow, and given the age of the unit and the amount of use it has had we’ll soon end up rebuilding it.

DC watermakers often get bad press, but in my experience most of the problems can be put down to poor installation—inadequate cabling, too far from the batteries, difficult access for maintenance, etc.; lack of servicing; and an over-reliance on gizmology—all of the wonder add-ons that promise to do it all for you (but seldom do).

I check the water quality every time I run the unit, flush after every usage, check and change the filters regularly, and store it properly every time we leave the boat.

Being able to get to the unit makes all of this easy, and performing daily checks allows any fault to be identified well in advance of it becoming serious. Remember the old adage: ‘If a job’s easy, you’ll do it’.

Pic 3 Make your water maker accessible

Sadly, it’s becoming more difficult to buy such a basic unit, as all of the manufacturers seem to want to offer more dubious ‘convenience’ features to out-do the competition. It’s no longer possible, for example, to buy the very basic Spectra model we have. I think this is a backward step, and wish they would stick to simple models, or at least offer them as an option.

In fairness, Spectra have been faultless in all my dealings with them, and offer excellent customer support via their website, and I have no complaint with their product.

I understand that in January of this year Spectra were sold to Katadyn, Swiss manufacturers of watermakers, and one of the few to still offer a really simple model range (their Power Survivor models), so it will be interesting to see what they do with their new acquisition, range wise. I also hope that the new owners have the wisdom to ensure that Spectra continue to offer the same levels of technical support.

LED Lights Come of Age

When Pèlerin was launched in 2008 there were few legal LED navigation lights available, the sole one for our boat (>12m LOA) being the Danish Lopolight, so we installed one of their combined masthead tricolor and anchor lights. We didn’t suffer from any of the problems that others seem to have had with ours, and up until last year it was working well. But it rapidly began to fade then, and soon was far from adequate.

Pic 4 Davis anchor light

So while we looked for a suitable replacement we bought a neat little Davis Mega-Light Utility anchor light, which comes with a choice of LED or incandescent bulb. It has an internal light diode to switch itself on after dark and a decent length of cable to allow it to be suspended in the forward part of the rigging, where it can best be seen in a crowded anchorage. We use the LED bulb (surely that’s the point of having one?) and it’s bright, legal and effective, and so far has performed well.

But we prefer a masthead anchor light for remote anchorages, as we believe it is easier to see against a dark backdrop. We also prefer to use a masthead navigation light when on passage, as it is energy efficient and affects night vision less, so we wanted a replacement for the Lopolight.

New masthead light

We eventually opted for the Orca Green Marine unit, which also has a photodiode, to turn the light on and off automatically.  It even has a flashing option should we want to pretend we’re a hovercraft. So far we’re very pleased with it:

  • it’s easily visible over the legal distance,
  • it’s USCG approved,
  • and the current draw is minimal (c. 0.3/0.4 amps).

However, we had always wanted to change our Aqua Signal Series 41 navigation lights to LED bulbs, but as no legal versions were available at the time we didn’t bother, reasoning in any case that as we tended to only use them when motoring, what did it matter anyway, the alternator would easily cover the power required.

But I’d always had in the back of my mind the comments of a Master Mariner I knew who told me that he wished that yachts would not use masthead tricolor lights, as he said that bow and stern lights made it far easier to ‘read’ what the yacht was doing.

Last year we learned of the MAST range of LED replacement bulbs that would fit our lights, so we bought a set. In the old days most people who made the change simply bought white LED bulbs and installed those, but I had heard from several sources that these were in fact illegal as the colour was incorrect, and outside the permitted parameters.

The MAST bulbs come in red, green and white, and apparently are colour corrected, and claim to meet the regulations for vessels up to 20 m. They’re not cheap (around £49.00 in the UK) but they are super bright, the colours look right and, once again, the current draw is massively reduced. As a result we’ll certainly use them when under sail in busy areas.

Interior lights

Moving below, we’ve changed nearly all of our bulbs to new generation LEDs which deliver clear, bright white light with no downside at all—they are a huge improvement over earlier offerings.

So the only bulbs we have on the boat now that are incandescent are ones that we simply can’t get LED replacements for. As a result of all of the above changes we’ve substantially reduced our daily energy requirement, which in turn means less charging time.

But we have probably reached the limit of ways in which we can further reduce our daily consumption, so we still have work to do on the supply side, perhaps starting by replacing the solar panels that we’ve ditched.

What else might we do?

living off grid means wind and solar

We’d love to try one of the impressive looking and powerful hydrogenerators as this would seem to be the perfect answer to our energy shortfall when on passage. (We have no space to fit a prop shaft alternator due to our engine configuration, which is a pity as it is a neat and effective solution.)

But the price is still prohibitive, and the only people we know with extensive experience of the Watt and Sea unit, report that although the output is impressive they had recurring problems with the mounting bracket cracking during their recent circumnavigation.

Alternatively, there are newish offerings from innovative company Swi-Tec and SAVE Marine, or the established Eclectic Energy unit. None of them are cheap, especially once you add in ancillaries, regulators, etc. Maybe one day…if we win the Lottery!

But it seems logical that we’re going to get far more bangs per buck with a really effective new solar installation that will work for us every day, bearing in mind that we spend the vast majority of our time at anchor, not on passage. Solar works just as well on passage, too, so that’s almost certainly the way we’ll go next.

KISS—You know it makes sense

Our adherence to the KISS principle hasn’t caused us any grief or discomfort, far from it in fact. Keeping the boat simple has saved us much money that has been put to better uses during our travels.

And it has meant that we’ve wasted far less time on maintenance or sitting around waiting for parts to arrive when we could be out enjoying ourselves on the water. Simplicity 1, Complexity 0 in our view.

Further Reading

102 Comments
Oldest
Newest
Inline Feedbacks
View all comments
Tim G

Colin, so with the flexible panels you total 180w of solar overall? I’m surprised. I’m sure there is a good and practical a reason you haven’t doubled up that setup but I’d be keen to hear? I plan to get 300w on my arch this year from my existing 100w but that is based on the fact I can easily do it rather than practical experience.

Colin Speedie

Hi Tim

part choice and part lack of choice!

We didn’t want too much weight and area on the arch, and figured that if we had the panels articulate (and we could be bothered to move them through the day!) they’d outperform fixed panels. And we had a ‘wasted space’ ahead of the dodger, so it made sense to use it for the semi-flexible panels, even though it wasn’t an optimal site.
The second part was we had to go with what was available at that time (2007) – panels today would give us far more output per sq.m.

Best wishes

Colin

Martin

Hi Colin, I had a similar experience with semi flex solar panels delaminating – 4 years on top of my bimini, so almost no mechanical stress and certainly no footfall. This year they got replaced by hard panels – higher output for a given surface area and lower cost.

Re hydrogenerators, have you considered the Aquair? I use it all the time on multiday passages, and it has been reliable so far (6 years). It is simple and inexpensive, and although I carry spares I haven´t had the need to use any. Output is 5-6A and it slows the boat a little (at a guess half a knot). The output covers most of the daily power use underway (incl electronic autohelm) and so it runs directly to the batteries unregulated, with solar and wind regulated on top. I find the set up works well.

Colin Speedie

Hi Martin

sorry to hear of your panels delaminating – it seems we’re not alone, which is disappointing to say the least.

We had an Aquair towed generator, but for some reason it never worked. They seems to think I’d wired it wrong (I hadn’t). It was prohibitive to bring it back to the UK for repair so we threw it out in Trinidad. I don’t think the fault was with Ampair who made it, as I’ve never heard of anyone else having a problem, and they have a good reputation as a company. I think I know what may have happened, but as it’s pure speculation I can’t go into it here.

A pity, though, as we had great hopes for it. Good to hear yours works well. You do hear of people losing props, but that’s it. And they offer good value for the output.

Best wishes

Colin

Henrik

Hi Colin
Thank you for another well written article. We have the same configuration as you, except of the fact that we have 24V 600Ah and at the moment no solar panels. Now we are in the thinking of a relocating and new installation of a solar system. The main question is how big (watt and size, two big ones or four smaller ones) and of course where to place the panels. Gluing flexible panels to the deck or doghouse roof will make the panels exposed to shadows from the rig. We have a targa, but that’s occupied by the wind generator, gps compass and Iridium Pilot antennas. One possibility we see others do is making an arrangement on the rail, and spread out the panels when condition permits, but we´re not convinced that being a good place either. Any recommendations?

When it comes to the Watt&Sea hydro generator we´re very pleased. We choose the large propeller (you can choose between three sizes depending of your boat speed) and at 7 knots it deliver enough power to run all navigation and communication equipment, and still charge the battery. At 10 kn boat speed it performs very good, making us able running all systems onboard whit out discharging the battery. That said, I must admit it´s not that often we experience 10 kn boat speed. We agree that the mounting bracket should be made more sturdy because huge forces is made on the bracket when the boat speed increases. Looking at the manufactures website, it seams like the generator now comes with a new type bracket appearing to be made of aluminum. Ours is made of some plastic (acryl) like material, but we haven’t had any failure on it, yet.

Colin Speedie

Hi Henrik

I wouldn’t rule out putting semi-flexible panels on the deck where you suggest. We had no issue from the output of our panels, and it was easy to simply move the boom to one side with the traveller to avoid too much shade. The problem was the durability of the panels. And until such time as we hear good reports of semi-flexible panels lasting as promised, that would be my concern.
Putting solid panels on the guardwires is popular here in the Caribbean, and it’s easy to rig up some means of adjusting the angle through the day to achieve maximum output at all times. My concern there would be the risks of damage in bad weather – I don’t like anything on deck that doesn’t have to be there, and avoid additional windage like the plague.

We have one good quality solid panel that we put out on deck when we’re in harbour. It’s long and slender, so that we can stow it in a surfboard bag when not in use. Cheap, simple and safe, it works really well.

Thanks for the update on the Watt and Sea, and it does sound as if the bracket has been modified. I see more of these around all the time (our current neighbour at anchor has one), and price apart they seem to highly attractive.

Best wishes

Colin

John Harries

Hi Colin,

I agree entirely that the trend that we are now seeing to festoon boats with lightly mounted solar panels is not a good thing. One wave strike and off they come, doing a lot of damage on the way. And that damage could be to a person. The thought of a large solar panel full of sharp edges mounted on the lifelines next to the cockpit that could come hurtling at you propelled by a big wave is really scary.

I know I have said it before, but large poorly mounted solar panel arrays are one of the most unseamanlike trends I’m seeing lately. More here.

Matt

40 kilos of glass and metal, held to the stanchions with a couple of 18-gauge stamped clips, being hit by a breaking wave? No thank you.
For fixed installations on shore – like on a house roof – building code requires solar panels to be braced with hefty mounting racks, tied into the main structure at multiple points. I can’t imagine why anyone would think you can get by with less on a boat.

Re. flexible panels:
So far, I’ve only come across two encapsulation systems that (a) can use reasonably efficient cells, and (b) are durable enough for a long lifespan: Sunkat ($$$$) and Gochermann ($$$$$!). I’d love to hear about alternatives.

Pat Kelly

Hi Colin
Thank you for a Very useful article. As Thoreau wrote: “Simplify, simplify.”
(within reason, of course!)
Pat

Colin Speedie

Hi Pat

Thoreau was a very wise man!

Best wishes

Colin

Ted simper

We have 380 watts of solar on a stern arch. This coupled with the Duo Gen from Eclectic Energy meets all of our power needs while on passage. We would like to add about 100 more watts of solar as at anchor in the tropics we fall a little short of our daily usage. Many boats we have met on our transpacific voyage have 500 watts or more.

We do not have and have not needed a backup genset.

Colin Speedie

Hi Ted

solar is so good at anchor – silent, always on duty. It’s finding space for it! But with far better output in terms of area it’s getting better all the time, and with lower prices it’s hard to see why people don’t use it more – what’s not to like about solar?

Good to hear a good report on the Duogen – we see a lot of them, certainly more of them than any other external hydrogenerator.

Best wishes

Colin

Scott

Colin, nice article, however, other than your discussion of LEDs, you didn’t say anything about the load side of your equation. When underway, do you use an autopilot or wind vane? Do you have refrigeration? Any other major load centers?

Colin Speedie

Hi Scott

we have an utterly useless fridge (not enough insulation), which uses far more power than it should, and we use the autopilot very little. Only for motoring and occasional use close to land where a wind vane isn’t at its best. Other than that we have a 12v water maker – those are our three ‘big ticket items’.

If there fridge was better we’d have no problem meeting our energy needs at anchor if there was a trade wind breeze and reasonable sunshine. We’ve been at anchor here in Culebra for over a week and not run the engine once to charge the batteries.

Best wishes

Colin

Marc Dacey

Aside from the obvious suggestion that you make your boat unliveable by tearing apart the cabinetry and redoing the insulation, we have approached this issue from the opposite side: the fridge less opened is more efficient. We have a fairly typical and reasonably insulated NovaKool Danfoss-type compressor that’s enough to make ice-cubes when set to “one” on all but the hottest days, suggesting sufficient isolation of the box from ambient heat. But it does have one of the bigger draws. How much better, we reasoned, if we only opened it a couple of times per day? We are considering therefore an well-endorsed Engel drop in fridge/freezer (which could live in the pilothouse in an unused pilot berth). This would hold drinks, snacks and fruit for “on watch” or casual noshing, but in a smaller space with a far lower draw (we estimate 25%) of the main galley unit. Round bottles and cans being less efficient of space than cube-sized, stackable parcels, we would get a better use of space, as well, I would think. Lastly, of course, if one unit goes on the fritz, we lessen the likelihood of using our cold food stores within 24 hours. While these units are used on boats fairly frequently as old-style “icebox” replacements or as a step up from the portable Koolatron or Igloo-type 12 VDC “camping coolers”, I have heard very few instances of them being used as “auxiliary coolers” in the fashion I have described, but if you open a galley fridge less often, physics suggests it will require fewer amps to stay cold.

David

Hi Marc,
We had something similar from a different manufacturer. The trouble we had was caused by the refrigeration unit being attached to the drop-in unit. That means the hot air coming off the unit is trapped in the same compartment as the insulated box. The compartment got very hot, and therefore the box struggled to stay very cold and was inefficient. It was like having a freezer located in an oven. It can work, but it has to work very hard. You may want to consider moving the refrigeration unit a short distance away from the cooler box, into another compartment that can be vented. That way the heat won’t end up in the same compartment as the box. We ended up separating the refrigeration unit from the box it was attached to and building a partition between it and the cooler box so that the box wouldn’t be exposed to all that heat.
Hope that’s helpful.
David
svTigress

Marc Dacey

Yes, that is helpful, David, and thank you. My only question about this unit was that the cooling unit was on THE BOTTOM of the box to be cooled, which struck me as counter-intuitive as you point out. The solution would be to do as you did (and there might be sufficient hose installed on this unit to do that); to pick a model with the moving parts on the side and to keep it just secured in a shady spot; or to vent adequately the area around the compressor. In my case this would be a beam-spanning engine bay that would have powered, switchable ventilation for the fresh air exchange to benefit the diesel, which might suffice. But it certainly is a consideration. I have a place adjacent to my heat pump and the two units could share a Venturi-equipped pan to shunt condensation overboard.

David

Hi Marc,
Replying to your comment below, my unit had the refrigeration unit on the side, and there was even a vent near it, but that wasn’t enough to keep the compartment ventilated. Even after we added the partition to keep the warm air away from the cooler box, with a vent right next to the unit, it got so warm in there that the unit would run almost all the time, very inefficient, and the box still didn’t freeze very well. We ended up having to add a low power 12v computer fan as an exhaust near the vent in order to keep the area ventilated, wired in series so that when the refrigeration unit cycled on, the exhaust fan would come on also. Amazing how much heat those units generate, even just ta iny little cooler/freezer unit. After all that, the thing worked fine, but whenever we had it on it would use as much electricity as our main fridge, really increasing our daily energy budget. In the end, we decided that the extra power requirements weren’t worth having the separate freezer. I ended up removing it and selling it, leaving that compartment as a convenient locker which we use much more than we used the freezer. Now we have just the tiny freezer in our fridge, the size of two hardbound books. The tradeoffs we make for freedom…

Eric Klem

Hi Marc,

A while ago, I had someone who was fairly knowledgeable tell me to relax about trying to save energy when opening the fridge door at home. This got me curious and I started looking at the numbers for it and discovered that he had a point. It doesn’t take much energy to cool down air it turns out. Air has a specific heat of around 1 kJ/kg/K (or C). When compared to water which is around 4.2 kJ/kg/K, it seems like it is definitely lower but in the same ballpark. What makes all the difference is that air is not very dense. If we assume an icebox is 300L (10.5 ft^3), it takes 0.38kJ to cool all that air down a single degree celsius (this is at 100% efficiency but I am looking for relative numbers). If we compare it to a single 1L Nalgene of water, that takes 4.2 kJ of energy to cool it down that same degree which is 11 times the amount of energy even though the Nalgene is much smaller.

I still think that you are very wise to try to limit the number of times that you open the icebox but I think that a lot of people really discount the amount of energy it takes to cool down a large mass. Freezing is even worse as it involves a phase change and a larger temperature decrease. What this means to me is that you should try to bring food aboard as cold as possible and make sure that stuff you take out goes back in the icebox asap so that it doesn’t have a chance to heat up. In your case, you might save a lot of energy if people are happy drinking drinks out of your drink fridge that are 50 or 55F instead of 35F. Also, there might be something to be said for putting all the drinks in on a sunny day when you have excess power from solar instead of putting a few in each day regardless of solar output.

I hope this is helpful.

Eric

John Harries

Hi Eric,

That’s really interesting, and has certainly taught me something useful—as usual, nothing like an engineer’s numeric approach. No question that top loading fridges are a royal pain.

I do wonder though about frequency of opening. I would love to tell you that at the beginning of meal preparation I get everything out that I will need in a very organized way, but the truth is rather different. I would guess that for a typical dinner I, being a bit absent minded, probably open the fridge 5-10 times, so I’m thinking for the more drifty among us, a top loader is still a better solution?

The other thought would be that even if I was super organized and got everything out at the start and put it back at the end, maybe that would not be a good thing since all of those unused foods that went back in the fridge would have warmed up while I cooked?

Anyway, all academic for us in that we have a good fridge/freezer system and the work to change to side loading would not be worth it.

Eric Klem

Hi John,

I think that you are right that leaving food out while cooking is going to use a fair amount of energy for re-cooling it. We figure out exactly what we need, get it all out in one opening and cut off whatever we want to cook and then put the remainder right back into the fridge. Like mentioned elsewhere in the comments, we tend not to do cold drinks which makes a big difference. This may seem like a bit much to some but it allows us to get by with very little power generation for people who have refrigeration.

And I agree that a top loader is still more energy efficient. With a top loader, I would suspect that you exchange less than 10% of your air (complete guess) which would make the math above another 10X so that cooling the 1L nalgene would be the equivalent of 110 openings.

Eric

Marc Dacey

Yes, it is helpful, Eric and thank you for the science.

On some level we already know this as we use a relatively inefficient Koolatron box on our smaller boat (it uses a Peltier-type fan/motor). We have learned that if we pack it with cold food, or with frozen ice packs, we can keep everything colder longer. We also unplug it and wrap it in a sleeping bag when purely sailing, and keep it covered (but with the fan vent clear) when motoring. Items frozen, such as blocks of cheese, can remains so for a couple of days with this method. So it makes a lot of sense to shop at night!

Marc Dacey

David, that’s an interesting conclusion, both in the sense of how hard the “portable” compressor works and ultimately its affect on your energy budget. By chance, I stumbled across a Craigslist posting for a Pelican cooler won in a contest: a local sailor has never used it and wants less than half the price when new. Perhaps a good solution is to go passive and make ice while the sun shines in the form of self-contained freezer packs, and then just to transfer cool beverages and fruit to a really good unpowered cooler. Might get several days out of that at zero amps! This is a great place to hash out ideas, by the way.

Ann

We’re heading for warmer climes soon and are considering adding refrigeration to our boat. Does anybody have any experience with solar refrigeration? We’re looking at SunDanzer (www.sundanzer.com) which is based on NASA technology. They have a battery-free, plug-and-play solar option BFR105. There is no information on the BFR105 model on the sundanzer website, but, dealers have it.

Colin Speedie

Hi Ann

it’s always good to see innovative products coming to the market, and this is obviously one. But i think that (at present) this is a domestic only arrangement – look at the weight (230 lbs) for example.

But it’s something I’ll try and find out more about – thanks.

Colin

Dick Stevenson

Dear Colin,
Another fine article. Thanks.
A couple of thoughts: I wish manufacturers would realize that not insulating reefer/freezer boxes sufficiently is going to be a constant annoyance in the years and decades to come and reflect on the company.
Your comment about nav side lights being preferred by ship’s crew over a tricolor seems to me well taken. I have often thought that a masthead light seen from miles ahead on a sailboat in a seaway pitching, yawing, rolling etc. must present a confusing picture. On the plus side, since installing an AIS transponder, I have noticed that, 4-6 miles out, ships shift their course just a bit allowing them to clear us without drama. I have suspected it is a relief for their masters to have clarity on our average speed and course that a masthead light can only suggest. (This is such a boon to our safety that I would take this opportunity to urge all to turn off their AIS output when it is un-necessary for safety. Our crowded areas (Solent, Long Island Sound, Narraganset Bay etc.) are so cluttered with signal returns that I worry that ship’s crews will filter out their class B receive capacities because of the annoying clutter and not turn them back on when offshore which is when I really want them to receive my signal.
Finally, I would be hopeful about Katadyne taking over Spectra. We have used a Katadyne 160e for years for all the simplicity reasons you mentioned and have been very satisfied. For those largely dependent on watermakers, I often recommend having 2 of the smaller Katadyne units (makes for very easy installation), exchanging daily use and promoting redundancy in essential systems. Their only down side for us was so-so amp/gallon ratio. Maybe that is why they acquired Spectra? One hopes.
My best,
Dick Stevenson, Alchemy

Colin Speedie

Hi Dick

thanks for the kind words – as always.

You raise many good points. The saving builders make by using 5cm over 10cm insulation must be so insignificant as to be derisory. Why ‘spoil the ship for a ha’porth of tar’? The worst of it is that it has damaged the joinery around it beyond repair.

I totally agree about sidelights, and could understand what he was telling me, so I’m glad we now have that option without a big amp penalty. And I, too, have noticed just how ships make early, small alterations for us. Much better than the way things used to be. And we never put the AIS on except on passage – and I think you’re right about ships filtering out Class B transmissions – there’s simply too much information in some places.

I like the super-simple water makers, and hope that the marriage between Spectra and Katadyn will be a very happy and successful one. Our Spectra is away having surgery and we miss it – not least because muggins is having to lug jerry can of water everywhere – just like the old days!

Kindest regards

Colin

Marc Dacey

Colin, we appear to have very closely aligned feelings about ship’s power and sources of generation, as well as best-practices watermaking. Your setup mirrors our plans, save that I have yet to install a roughly 1100 Ah battery bank. I can carry this weight low and centered where many cannot, and my rationale is that I want to store volts while the sun shines/wind blows and yet I want a greater “working range” of useful power, which of course is no less than 50% state of charge, and better if it is more than that. Like you, while we will carry one or two Hondas in the “companion” format for backup and using stock power tools for short periods, we didn’t want to have a separate diesel genset. By the way, we have 4 x 135 Kyocera hard panels on a steel pair of braced arches feeding into an Outback FX-60 MPPT. Results even at 44 North in March seem promising.

Thanks for the field report/reality check on our own thoughts.

Colin Speedie

Hi Marc

that’s some battery bank! I thought ours was big enough. Ours is well situated close to the engine, water maker etc. in a custom made aluminium box. The weight is a pain, and I’ve had to do quiet a bit of trimming with gear to balance it out. Roll on Lithium batteries.

Your reasoning mirrors our own – lots of capacity saves the batteries from deep discharging. We’ve never had ours below 75%, probably one of the reasons that the old ones lived so long. And apart from a test run we’ve never used the Honda for charging. Power tools yes, though. But it’s always good to have back up for your back up!

Best wishes

Colin

Marc Dacey

Not to seem entirely agreeable, Colin, but I agree that not dropping below 75% SOC (and hydrocaps and monitoring and temperature sensing and equalization and the whole not onerous but easily deferred care and feeding of a big bank) is the way to get maximum time out of what is a big investment in cash, proper securing and raw space and weight.

We plan to shunt all charging inputs (two alts, externally regulated; solar and wind) to the house bank; relays will send the “spillover” to starting batteries and a 12 v near the windlass forward. Switches will be able to isolate/divert power flows should maintenance or defect require it. It’s not as complex as it sounds. The goal is to run fridge and comms at anchor for five cloudy, windless days if needed without using the engine to charge the bank. Realistically, that will be exceedingly unlikely to happen in the tropics, but that’s how we get to fully exploit a more narrow band of charge capacity than is typical.

With our full keel steel boat, the weight is simply not the issue if we are sensible. In fact, I expect our plans to put six L-16s 6-volt batteries nearly directly beneath the center of effort to go some way to stiffening matters. There are very few parts of the boat, which was custom-built, I am unable or unwilling to modify, which helps enormously. If I had to put AGMs on their sides under settees randomly, I would have an entirely different approach. I can see that in a fast, capable boat such as yours is, the weight savings and flexibility of lithium batteries would be persuasive; in our case, we already know that a 4 knot SOG around the world would be a pretty good average, and so the ubiquity of forklift/floorsweeper/golf-cart style lead-acid batteries is why we are sticking with them. On the other hand, AGMs for start and windlass 12 VDC make some sense. We’ll see.

While we have an inverter in hand, a nice pure sine one at that, it will be used for brief periods of microwave and coffee making, and in those situations where DC-DC charging is not practical. The Honda or Hondaesque portable gensets can be used singly for power tools up to 10 amps of AC draw, emergency charging, or even to go ashore in distant lagoons to make friends and earn taro by an afternoon of impromptu contracting. It’s not implausible that I will be able to do light welding and fabrication aboard, which I could trade for diesel and rum in the cruising community. All will be revealed in the fullness of time.

David

Hi Colin,
Thanks for a great post. If you are considering replacing the delaminated panels, we’ve been impressed with our semi-flexible panels from Aurinco. They are monocrystaline (highest efficiency commercially available), only 1/8 inch thick, and can be glued or screwed to the deck and walked on. One thing I like especially is that there is no electrical box raised above the panel, just two little wires coming off them, with an entirely flat surface. You can also sew fabric to the edges so they could be attached with zippers to a canvas bimini top setup rather than adding the metal racks that most panels require. We glued (3M 4200) and screwed 7 of them (4x100watt+3x25watt) to a slightly curved section of cabin top. We walk on them when unfurling and furling the main. After four years of full-time live-aboard, they look new and work great, supplying all our electrical needs unless it’s overcast. We also had great service and support from the company while buying and installing them. It’s a small company owned and run by the inventor and his wife. He answered all my questions personally and was a pleasure to work with. They are not cheap, but worth their cost in our view, as we rely on them every day and they should last many years.
Highly recommended.
Fair winds,
David

Colin Speedie

Hi David

thank you very much for the recommendation, which I’ll definitely look into. Sounds very promising, and maybe just what we want.

Best wishes

Colin

David

Regarding simple watermakers, Spectra does still offer the Cape Horn Extreme, which has no computer gadgetry to break. It’s just manual valves plus two simple electrical switches for the pumps. It runs on 12V and has two identical pumps, either one of which can power the unit independently for 7GPH watermaking at 7 amps, or running both together gives you 14GPH at 14 amps. It was designed for non-stop round-the-world racing where a watermaker failure would end a whole campaign. We use one pump during the day when living at anchor with solar power, and both pumps if running the unit when we have plenty of power like while motoring. The two identical pumps provide comforting redundancy. It’s also designed to not have problems with aerated water when used under way. We bought a used unit, which has been mostly trouble free. The Cape Horn is also cheaper than other models because of the lack of the computer controllers. What you give up are things like remote control from a convenient panel, automatic salinity testing with electric valves to switch to the tank when ready, automatic flushing every X days while you’re away, automatic pickling, etc. You need to go directly to the unit and flip a few valves and switches to start it up, same to shut it down. We don’t mind, and prefer the reliability that comes with the simplicity. The biggest issue we’ve had is with parts availability, as Spectra closed down their online store, and the parts distributors don’t seem to carry good stock. Really hoping that Katadyn puts the parts online again, as that allows easy ordering and shipping to wherever we may be.
David
svTigress

Colin Speedie

Hi David

I know the Cape Horn Extreme and have in the past recommended the unit to owners going off the beaten track. It was, however, too big for us, and we have the old (no longer available) Ventura 150 that has none of the electronic gadgetry you list – it’s like a baby Cape Horn, totally manual. As such you have to do everything manually, but I’m fine with that – you can see problems coming before they become serious.

People who work with water makers all the time tell me that the biggest problem reliability wise are the electrical add-ons, and in my view they are not worth having – KISS again!

Best wishes

Colin

David

Agreed that it’s no big deal to operate manually. It’s nice to have a feel for how it’s working.
One thing we may end up adding is Spectra’s new ion purification gadget. While flushing the unit after making water, it uses a small current to ionize the fresh flushing water, making it into something like low grade preservation fluid. What that would mean is we can leave the unit for up to a month or more without flushing it, without the need to pickle it. Frequent pickling greatly reduces the life of RO membranes, so that would help longevity and eliminate the hassle of pickling the unit or finding someone to flush it every 3 days when we leave the boat. I’ll bet these things get quite popular, as they would work on any watermaker. The big drawback is price, almost $1000, which stings a lot.

Marc Dacey

FYI, Colin: the Spectra Ventura 150/200 unit seems to be available here and perhaps elsewhere: http://www.marinewarehouse.net/spectra.html#Ventura

Colin Speedie

Hi Marc

that’s the one we have – I was told it had been withdrawn. Thanks for pointing that out.

Kind regards

Colin

Steven Schapera

Thanks for the article. I am a long-term subscriber to the KISS principle, and love the way it gives me more confidence knowing that I can fix almost everything that could reasonably go wrong.
One thing I haven’t yet worked out…I have a small Honda EU10i (1kw) petrol generator which I use on the odd occasion. I would love to know if anyone has had any success feeding using a small generator to provide charge to the batteries through the shore power charger? I think if I just plug it in it would stall as too much current is drawn at the start. Is there a way to do this “softly”?

John Harries

Hi Steven,

I can’t see that your battery charger would stall under the load of your charger unless it was quite large. For example, a 40 amp charger at 12 volts would draw 40 x 12 = 480 watts or half of the capacity of the Honda. Now that assumes 100% efficiency, which is not the case. But lets say the charger is 70% efficient (I’m guessing here) that would result in around 700 watts, so still good. Also I don’t think that the start surges on chargers are very high. Anyway, that gives you the arithmetic to work it out for your situation. The point being that watts are watts regardless of voltage and are calculated as amps x volts= watts

One issue. I think I’m right in saying that those Hondas don’t put out a true sign wave, but rather a square wave and some chargers may not like that.

And finally, forgetting the theory for a moment, I know several cruisers that do exactly this. I even have first hand experience since when we took care of a German boat for a month in a Greenland winter, that’s exactly how we kept the batteries charged.

Colin, I think this is what you are doing too?

Steven Schapera

John
Thanks for taking the time to reply directly, much appreciated. The cause for my concern is that when I plug into shore power and begin charging, I see the amps momentarily scoot up to about 65 or even 70 and then it quickly drops back to (say) around 30. Its that “surge” that has me worried as I know that if I hook up a big power tool to my generator it can stall the generator with its startup current requirement. Anyway – I will give it a try, as it would be a wonderful backup. Again, thanks for taking the time to advise me – that alone is worth my annual subscription fee.

Colin Speedie

Hi Steven, John

yes this is what we’ve done. BUT – John’s right, not all chargers like the square wave output, and some won’t handle it at all (I’m told). Ours does – just.

I can’t say for certain, but I’d suspect that the larger 20i (the ‘inverter’ model) would be a much better bet of you plan to do this regularly, and has more power output in any case. And the best ones are Honda and Yamaha – quiet and reliable.

Best wishes

Colin

Marc Dacey

I would concur that the output of the Honda EU 2000 model gives more “breathing room” for the purposes of charging; I have yet to attempt it, but I am told that I can even get past the 17 amp draw of March pump and Marine Air start up with a single EU 2000 in order to have heat and cooling at anchor. You (Steven) asked ” Is there a way to do this “softly”?”, and I would say very much that the answer is “yes”, although on general principles I would do it with a Honda 2000. The Dometic “SmartStarter” which I suspect is just a bunch of rectifiers and capacitors packaged attractively, but which is supposed to reduce or eliminate those spikes in draw that can stop your generator. This isn’t an endorsement as I am still researching, but I can’t fault the principles in play.

Eric Klem

Hi Colin,

Thanks for the update on how your system is doing. Your experiences with your flexible solar panels sound very frustrating. If you do end up replacing them, I would be very curious to hear what you decide on and then how they hold up. Our single 140W panel is marginal for keeping up with our loads and I have been thinking of putting 2 ~50W flexible panels on top of the dodger as it is an unused space and there is good airflow under it to help keep them cool. I see that you can buy clever snaps now that go on the dodger fabric and make the panels easy to remove but fairly secure at the same time. I actually just built a new articulating mount for our 140W rigid panel today.

Eric

Colin Speedie

Hi Eric
we’re actively looking for replacements (the old ones are snoozing in a dumpster).
There are some rurally interesting new ways to attach semi-flexible panels to things like dodgers and bikinis, not least with zips, so that they can be removed ahead of bad weather, or when the boat is on the hard.
Weight remains an issue, in my view, and the poor record of reliability of these panels – if and when they get that right it will represent a major breakthrough.
Best wishes
Colin

Dick Stevenson

Eric & Marc,
There have been knowledgeable marine systems guys who have argued just that: opening the frig to air is not a big deal current wise as air is cooled so easily, but I do not remember at this time who they were. For myself, I believe this to be accurate and is an argument in support of the front opening reefers that seem to be more common nowadays. Marc, if yours is a top opening reefer, I especially think that you have little reason to be concerned. Following this, I would suggest delaying the second portable cooler until you have time living aboard under your belt. It can always be added later with relative ease. I personally would not want a heavy piece like that around if in a seaway and wonder whether it would be more of pita than it was worth in day to day living, installation and electrical usage-wise.
As to cold drinks, I still like beer cold, but many of our other drinks we have migrated to warm or cool. And we have not bothered with ice for years, even though we have a large freezer.
My best, Dick Stevenson, Alchemy

John Harries

Hi Dick,

So true on ice. We have not bothered for years and don’t miss it. In fact I think one of the biggest and simplest ways to save energy on a liveaboard boat is to ween ourselves off cold drinks and ice cubes. Has health benefits too in that sugary drinks are pretty foul when warm, bur water with a little lemon in it is fine that way, even on a hot day. And of course whisky is always better without ice!

Colin Speedie

Dick, John
ice? We should be so lucky!
Best wishes
Colin

Marc Dacey

Dick, thank you once again for the sage counsel. Our “domestic” shake-down cruise (Toronto to Halifax and then overwintering before crossing the Atlantic) is intended to “reality test” some of our assumptions. In terms of installation, I have a pretty wide open engine bay, and the runs are not complex, nor is the weight (that of a small child) onerous in the places available. But yes, if we do not suffer in terms of amp draws once clear of the shore, I would rather have the grand in my pocket. Ice is nice, but not essential. We don’t drink sugary drinks, but fruit, fruit juices and cold water are good to have to hand, just as is hot coffee and soup on watch, for which we have a Forespar gimballed stove we can use as needed.

Bruce Savage

Thanks Colin, as always a really informative post embellished by excellent comments from the AAC community. My preferred approach has been to forego the wind generator and to concentrate on maximising solar. A good friend is a sailor, an electrical engineer and also has a domestic solar business. His advice to me was to use 24v domestic panels. His reasoning being that the right domestic panels:-
Will be robust enough as they are obviously made for outdoor use.
Are a lot cheaper because of economies of scale, competition and no marine label.
You should be using a controller anyway which will easily step down to 12v.

We now have 3 x Winaico monocrystalline 29o Watt panels mounted on a structure on top of our semi-rigid Bimini. This array is connected through a Morningstar MPPT controller and we now only need to run the generator or alternator on rainy days. In Aus the sun shines often so this system works amazingly well, and anyway we have no plans to travel anywhere where this is not the case. Battery bank is 800 amp hours.

Im not entirely confident of the panels (and Bimini) surviving a big storm at sea, but in general my advice is to absolutely maximise the solar area and use a MPPT controller.

Bruce

Colin Speedie

Hi Bruce

I’ve heard that about domestic 24V panels before, and your experience endorses it – thanks for passing that on.
My only concern would be that the average monohull would struggle to mount that much solar area.
And not everyone is lucky enough to live in sunny Australia. Here in the trade wind belt a good wind generator is an absolute must. Here in Vieques this morning our battery bank is showing 99% full after a breezy night.
A mix of wind and solar is the best bet for many people.
And thanks to you and others above, who have remarked on how important it is to have a good quality MPPT regulator.
Best wishes
Colin

Dick Stevenson

Colin,
I wish I could cite sources, but I have read some well presented testing and field data which suggests that the coddling of batteries is a bit of a cruising myth (especially the more robustly built modern batteries: flooded, gel or AGM). They suggest that, within reason, you get about a similar amount of amps out of a battery over its life span whether you coddle it (such as the 75% recharge level you adhere to) or whether you push them harder. Like sails never used in over 20 knots of wind, the less challenged battery bank will certainly last longer, but that does not mean that it has given more service.
If the above is correct, and my field experience does lead me to believe it is, then there are a number of implications. Most immediate is that charging by many means is far more efficient when batteries are more depleted. Trying to throw significant amps into an only partially depleted battery is frustrating. In ½ hour an alternator, genset charger, etc. will throw many more amps into a 40% depleted battery than it will into a 75% depleted battery, even with smart regulators.
I hope those with real knowledge weigh in. It is my take on the docks of the world that the coddling of batteries has become writ in stone. I will try to locate my sources.
My best, Dick Stevenson, Alchemy

John Harries

Hi Dick,

You are correct. In fact the latest thinking from, and testing by, Lifeline batteries indicates that the best way to get good life out of all lead acid batteries (liquid, AGM, and Gell) is to charge them with every amp they will accept, as long as you do not exceeded said battery’s acceptance voltage (typically 14.4 volts at 70F).

In fact charging batteries slowly may in fact decrease their life due to sulphation.

You should also have a temperature probe from your charging device, since as temperature increases appropriate acceptance voltage decreases.

I suspect that the reason that many sailors (and boat yards) found that charging slowly increased battery life was that they were using older chargers without temperature compensation and in this case fast charging could kill a battery very quickly, particularly Gell or AGM.

Much more on all of this in our battery Online book.

Marc Dacey

John, I will read this more closely. Frankly, if I have four instead of six L-16s (370 Ah x 2 at 12V), all I do is lose 220 pounds and the need to weld up a bigger battery box frame. The actual reduction in reserve power is not huge with my assumed daily draws. I’m aware I tend to overthink these topics, which is why AAC conversations are such a helpful tonic.

John Harries

Hi Dick,

In rereading the thread, I realized that I should clarify my comment above. While you are right that “coddling” batteries by charging them slowly is a myth, Colin is right that a starting recharging at a higher percentage of charge is the biggest thing you can do to extend the life of your batteries.

Somewhere Lifeline has a table showing battery life in relation to the typical level that the battery is discharged. Below 50% things don’t look good at all, but there is no question that average levels above 50% (like Colin’s 70%) are beneficial too.

That’s why our generator start battery, a cheap no-name brand that we picked up in a garage in Norway, has lasted 14 years: It is never discharged more than about 10% (our generator starts very easily) and is always immediately recharged to 100%

Marc Dacey

One of the reasons I had a possibly erroneously high opinion of Trojans was that we bought our boat in 2006 with *original* T-105s dating from 1988 (!) I later learned that a boat never off dock charging and regularly watered with an atypical discharge pattern, such as your bog-standard generator start battery, can in fact appear immortal. We ditched the ancient Trojans when they couldn’t hold 13 volts despite watering or charging of any regime, but it did underline how exceptional conditions can produce exceptional results. By contrast, I can get six or seven good years out of Canadian Tire batteries used as a combined house/start bank on my other sailboat, irrespective of charging regimes and electrolyte-minding. I suppose one difference is that I do not have the ability to equalize the cheap batteries with my “dumb” ferro-resonant charger on the smaller, older boat.

mike h

One thing that I have discovered in owning a residential array with individual panel monitoring is the detrimental effect of partial shading. It is truly surprising how even a small amount of shade on a typical panel can decrease its output to almost zero.

Given the obstructions around sailboats, I would suggest that sailors look for “shade-tolerant” panels. They may be a little less efficient in full sun; however, in typical usage they just might shine.

mike h

Colin Speedie

Hi Mike
quite right – polycrystalline panels have more shade tolerance, and there are other technical advances that make shade tolerant panels a good choice. A good average is in many ways better than peak power output.
Best wishes
Colin

Dick Stevenson

Hi John,
It is no surprise that your genset starter battery is still doing its job after 14 years. It is like the sails that are never employed in winds greater than 15 knots and are protected from UV. They will last forever. Batteries that have little asked of them and are re-charged completely upon minimal usage will last a long time. For me the assessment criterion of import is the number of amps delivered over the life of the battery bank and not that a bank lasted xx amount of years. Then the charging criterion becomes what regimen produces the most amps from a bank and not what charging regimen makes the batteries last the longest. For me, this is what is important in a house battery bank.
The cruising myth that I am referring to is whether the service (amps, not years of life) you get out of your batteries is really enhanced by coddling them. Some of the reports I have read (and my own experience) leads me to believe that, within reasonable usage, one gets a similar amount of amps out of batteries in a wider range of usage. In other words, letting your batteries get depleted to 50 or 40 % before charging is not going to make much difference than letting them only go to 70% when your criterion is the number of amps delivered during the life of the battery. Most people talk about the life of the battery bank in years as important when, to me, it is the total amount of amps that you get from a bank that should be the assessment criterion.
So, if the myth is just that, a myth, total amp output can be similar and your choice becomes: do you wish to charge in small increments more often or do you wish to charge in greater increments, less frequently.
My best, Dick Stevenson, Alchemy

John Harries

Hi Dick,

Yes, I agree. We are saying the same thing a different way.

However, what we should not lose sight of is that mainly solar boats with low loads (no freezer) like Colin’s have a huge advantage over us with our generator based boats:

With a generator we must discharge our batteries to at least 50% because otherwise the batteries won’t take enough charge to load our generators. Further, we tend never to fully charge the battery (except on shore power) because the amount the battery will take tails off with charge and so we would need to run our generators for 4-6 hours to top off.

The solar boat, assuming enough panels in relation to load and battery size, quite often reaches full charge. For example if Colin and Lou go out for the day and turn everything off, when they return the battery will be fully charged.

The result is longer battery life and less cost any way you cut it.

Of course, the other side of the coin is that they don’t have the 100 lb of great frozen food that we carry. Not a big problem if the boat is near the shops, but we (and I suspect you and Ginger) would get very tired of eating out of cans and dried food in remote places. As I write about here, the equation is simple: appreciable amounts of frozen food = generator. (Although that may change soon with better insulation of freezers and more efficient solar panels.)

The best of both worlds would be to have a generator for the heavy lifting and solar for topping off the batteries when the loads are low.

For others who are following his discussion: All of this is explained in detail in this Online Book.

Dick Stevenson

Good morning John, Agreed an on the same page. Dick

Colin Speedie

Hi Dick and John
Interesting discussion, and I’m glad you both agree on John’s hypothesis of solar vs generator, because it’s right on the money!
Just up and about here in Ensenada Honda, Vieques, to greet the first swallows of the season, and our batteries are at 94% charge and wind/solar currently charging at around 6 amps. This despite a windless night and sitting up to watch a film for hours.
As John suggests, you have to start with a different approach to go all 12V with no generator. And it does take more input in other ways (moving panels etc), and it isn’t without its costs (extra batteries and solar and wind) nor its inconveniences (no microwave, freezer, weight penalty etc) – but – it suits us.
Our decision was largely based on having run charter boats for so many years, especially as the boats I used didn’t have gensets. Batteries were ‘consumer durables’ to us, i.e. we beat them to death, huge discharge every evening, hours of engine running every day with high output alternators, and we were very lucky if we got two years out of a domestic bank. In my experience, deep discharging and then crank charging murders batteries.
We wanted to get away from that, so that’s why we went down this road.
And, currently, I agree with your assessment that a mix of generator and solar/wind would be perfect, especially if your preferred way of life aboard would be more sybaritic than ours (wouldn’t be hard!). But, I’m firmly of the opinion that it won’t be many years before renewables (of various types in combination) coupled with high tech batteries will make generators redundant for yachts up to 50ft, and maybe more.
We’d love a freezer though…..

Best wishes to you both
Colin

Fuss

All sounds good to me, however the 2 changes I am about to mention will help you when/if you have solar panel trouble again in the future.
Put some decent insulation in the fridge, I guess its got foam in it so rip it out if possible and put some aerogel matting in, while not perfect, it should make a difference.
Ok, so I know you don’t run your engine much but I guess you have some electrics that get switched on at engine run time. This reduces the alternators 110a potential output to the batteries. You are probably now going to say that normally the batteries are over 80% charged so the full amperage potential is not needed anyway. I would suggest to get yourself an industrial 150a alternator, charging at 14.8v so every charging opportunity is maximised. My experience is that quite often I see 140a of acceptance after not running the engine for a while.
Maybe you could buy one as a spare and try it out.

Colin Speedie

Hi Fuss
I agree that we’re going to have to look at the fridge, but it’s not the easiest of jobs as it’s a top opener with a solid internal structure, so no foam is exposed. We’ll certainly look at the aerogel matting, amongst (no doubt) other options – thanks for the suggestion. Once we’re in the US mainland I’m sure it will be like Aladdins Cave for such options!
The alternator I’m not sure about. We already have a 115 amp alternator (although it’s machine sensed) so I’m not sure how much we’d gain. I have extensive experience of using industrial type alternators (Leece-Neville, Balmar) some with adjustable output voltage levels, and it’s easy to go too far with them and damage batteries. I’d like to try a Balmar of a similar output to our original through a Balmar smart regulator, though.
As you’ve identified, our batteries are never allowed to fall to levels below 80%, so we simply don’t need to crank charge them. But a battery/temperature sensed alternator/regulator set-up could only help.
Best wishes
Colin

John Harries

Hi Fuss,

While I agree that better insulation and a better regulator are always a good idea.

You really, really don’t want to be charging batteries at 14.8 volts, except when equalizing. That will ruin gells and AGMs in very short order and even liquid filled batteries will have their lives significantly shortened and will require frequent water top up.

But wait, it gets worse. If you charge at that voltage and the batteries get hot, you risk a thermal runaway eventually ending in fire and even explosion.

And finally,charging at such a high voltage is all downside with no upside. The reason being that all that happens when we increase the voltage over and above the batteries acceptance is that the internal resistance rises so there is little or no additional current (amps) going into the battery from the increase.

I have simplified a bit here, but all of this is explained in detail in our Battery Online Book, which was written with the help of a major battery manufacturer who checked all of the recommendations therein for accuracy.

Terje M

Good article

We have gone through the same project on-board Maud when we upgraded her electrical systems. My plan was to keep to the KISS principle when we have refurbished and upgraded her. Within a year on two she is going to be a live-on-board boat.

This is not a 12 v boat. With modern technology I think I have found a very good compromise and still keeping things simple.

What have I done differently?

Advanced charger / inverter

I installed an advanced or eight generation charger / inverter. The Struder is just fantastic – it is a high quality Swiss product. The Struder is a very advanced charger and inverter with a “smart-boost” that provide a seamless supply of AC power, acting a charger when there is a source of main available either from shore power or from a generator, it mange any peak loads. It was expensive but have transformed the live on-board.

Some people will say that it too complex. Too use it is dead simple. It never fails.

Diesel Generator

The Paguro 3000 Compact generator keep charging the batteries when needed. It save the engine for battery charging. It also keep it simple – since I got one source of fuel on-board.

12 v Watermaker

The 12 V Dessalator D60 Freedom water maker gives me 60 litre of water every hour. It draws about 32 amp when running. It is energy hungry.

LED Lights

I have done what I can to reduce the battery usage. Navigation and tricolour lights are now LED.
Several of the cabin light are replaced with lights from Alpenglow. Their products are expensive. Looking back it was one of my better investments. The light from Alpenglow is not like any other LED lights. They give a warm light and you got a night light switch.
http://www.alpenglowlights.com/

My next upgrade
– Solar panels.
– Watt & Sea Hydrogenerator.
– Quooker hot water tap

Quooker Hot Water Tap

Quooker now got a new hot water tap called Quooker Fusion. They have been on the marked for some time with hot boiling water. They new got a tap that is used for cold / hot water and boiling water. Their 3 liter compressed tank for their boiling water is perfect for a yacht.

~Terje
Yacht Maud

Colin Speedie

Hi Terje
everyone has their own idea of what ‘simple’ is. Our idea of simple seems like ‘crude’ to some people, but it’s what works for us.
There are some very interesting products there that you’ve brought to our attention, and that’s the positive benefit of having so many interested and experienced people commenting on this site – and we can all decide what degree of ‘simple’ suits us best from a position of being well-informed.
Thanks for your helpful comment and best of luck with ‘Maud”.
Best wishes
Colin

Henrik

Regarding the discussion on “green” energy sources.
Why not use the water which we´re sailing on, to cool our fridge?
Anybody out there having real time experience on this type of fridge/ freezer cooling system, especially its energy consumption, compared to air-to-air cooling?
John; How will it be to install this kind of equipment on our aluminum boats, taking in to consideration that the trough hull item seams to be made of bronze?

Even if we try to stay whit out a genset onboard, a new technology from Whisper makes us in great doubt. Several of you have probably some sort of gasoline (Honda) generators as backup if wind and solar power let you down.
What about a relatively cheap, low consumption generator? It’s “green” taking in consideration it being a small, effective, low consumption, low noise generator. With its 60kg /120 pound, it’s a very small and neat back up charger. Its easy to find a good mounting place for it on board due to its neat size, and you don´t have to think about where, and how its stored or secured, compared to a 30 kg/ 60 pounds Honda petrol ”emergency” generator which you have to find a good and remote place to store on board, dealing with gasoline which you can´t keep “down under”, not mentioning the hassle bringing it out on deck to work on a rainy day, creating the well known brrrrrrrrr to all your neighbors.

Colin Speedie

Hi Henrik

very many of the boats we see here in the Caribbean have water cooled fridges, and it seems like a good idea indeed. I can’t see why the through hull has to be bronze, and it may well be possible to adopt a different fitting that would be more compatible.
Neat little Whisper generator you’ve put forward, and as you say at that weight and size it would fit a much smaller boat OK. I note that it’s oil cooled entirely. so no need for any extra plumbing and ‘yet another hole in the hull’ presumably.
It would be interesting to know whose engine they use.
Thanks for the heads-up.
Best wishes
Colin

Terje M

Henrik,

We got a water-cooled fridge; it is massive, and we love it! I changed the water pump a few years back; the compressor is more than 20 years old and still going strong. Except for the water maker, the fridge is the most energy-hungry item on-board. The compressor and water pump is using 7.7 amp when running. According to the manufacture, we should be able to bring that down to around 5 amp with an updated compressor. Our compressor and condenser is 12v from Frigoboat.

Our fridge is well isolated. When the fridge is running, we can hardly hear it. At times, we turn the fridge of at night just to save some power.

The exist for the fridge cooling water is the same as the bilge pump. I think water-cooled fridge is not that common in Europe? On a regular basis, we got other yachters knocking on our hull telling us that our bilge pump is running!

I do think we uses less energy than an air-cooled fridge of the same size. Number of water intakes and outlets on-board are more than what I ideally want. I am currently replacing all the seacocks with stainless steel seacocks.

~
Terje
Yacht: Maud

Marc Dacey

Have you considered a standpipe? It reduces the intake holes in the hull to exactly one, and all seacocks come from this pipe in one central location (usually in the middle of the boat beneath companionway steps). There are other, less obvious cleaning and servicing advantages to a standpipe as well; please see here: http://alchemy2009.blogspot.ca/2013/10/the-real-sea-monsters.html

Henrik

Hi Terje
To me it sounds like your water-cooled fridge is a similar system as water-cooled air-condition systems, which as you describe, are very power consuming.
What I have in mind is the Isoterm Asu 3751. https://www.indelwebastomarine.com/us/
The system utilizes the patented SP thru-hull fitting which incorporates a built-in passive heat exchanger-giving you the cooling power of water without the need for a troublesome seawater pump. It also replaces the galley thru-hull, so no new holes are necessary for installation! The system is nearly silent in operation and very efficient-even in tropical waters. Advanced electronics monitor available battery power and adjust the three-speed compressor for greatest efficiency. This stainless steel holding plate system will refrigerate a box up to 7cu.ft. SP systems for larger or smaller boxes are available by special order. Chilling Medium: Holding plate Power Requirements: 6A 12V DC; 3A 24V DC

Enno

Hei Henrik
I have got one of the selfpumping isotherm units. I find energy consumption with water temperatures in Norway (Nordland) almost insignificant. The same goes for noise.

Dick Stevenson

Henrik, I have been all over the site you url’d and I am unable to find a 60 kg unit at Whisper Power. Can you help? Dick

Henrik

Hi
Yesterday I was speaking to one of the engineers at Wisper, and he told me that their smallest generator, until to day only delivered in the All-in-one PowerStation, now is delivered as a ”stand alone” generator, weighing 60 kg. The generator is presented at a boat show here in Norway this week, and it is so new that they haven´t had the time yet to make a flyer to hand out or updated their web site I was told. Some technical details is to be found in the flyer for the All-in-one PowerStation:
https://www.whisperpower.com
The guy told me that the generator is based on a Wisper produced 300cc, one cylinder engine, having a variable throttle making it possible to tune the rpm from 2400 to 3000, giving a fuel consumption between 0,8 l/h to 1,5 l/h depending on the charging load. The power production will be reduced in accordance with the rpm, and if I got it right he claimed it would deliver 70ah 24V at 3000rpm if delivered with a 24V charger.
The generator can be delivered with a 220V AC inverter or a 12/24V DC charger, but due to the size and relatively low power production, its main purpose is to charge your battery bank, not supplying a heavy duty AC consumption. The noise made from the generator is 53 decibel.

John Harries

Hi Henrick,

Very interesting. Thanks for linking to this. I guess my feelings are mixed. I like the idea, but have an experienced based scepticism about that level of automation and integration: see this post. Still, I hope they can make them work reliably. The track record of small DC generators is abysmal to date, but there is no question that the fundamental concept makes a lot of sense. As usual, it will all come down to execution and after sales support.

John Pedersen

Since I’m living on a small catamaran, keeping weight down is especially important to me. So I decided to go without a stern arch for my solar panels. Instead, I have the panels on long cables of 4mm square section, and have fitted sockets so that I can plug the panels into the stern or near the bow. This enables me to put the panels anywhere at all, and I’m always able to find somewhere with no shade. A bit of shade reduces the output of a panel by a lot – avoiding all shade allows me to get away with 2×80 watt panels. Recently, my laptop has been giving me problems (very hard to start) so I have left it on continuously for the last few weeks – no problem at all.

Of course sometimes it’s a pain having to move panels to somewhere sunny, but very often, like here in the Caribbean, I can just leave them on the starboard side and they get full sun all day at anchor. And after a very cloudy week mid-Atlantic when I was getting low on electricity (I’ve got low on electricity only there, and the cloudy anchorage at Las Palmas, where I had a family of electricity-gobblers on board), it was great to be able to put the panels into such a position that whenever the sun did peep out, I was able to take full advantage of it.

This is not to disparage panels on arches – I’d have one if I could accept the weight penaltty but having a panel or two that can be easily mounted anywhere could be quite an asset to some. Even with an arch, I think I’d like to have a movable panel in addition. In dodgy harbours and storms, I bring the panels inside, where I have a place they can be safely stored.

Marc Dacey

John, a solution I’ve seen used with some success is to mount the panels securely on the lifelines so that they are vertical when not in use and can be angled with a notched wooden lever or strut when in use. Now, this wouldn’t work well in a spot liable to take a sea, but a catamaran is more level and dry than most and there might be a good idea here for your setup.

Enno

Hi Colin
A very interesting article and as usual very interesting comments. For what it might be worth, here is what I am doing:
The last years when we were mainly sailing short passages I focused on saving energy by installing the following items:
This combined with an alternator regulator and our 240Ah battery bank was sufficient for sailing in northern Europe. Especially the fridge is using very little energy in arctic Norway where water temperature is almost at fridgetemperature (actually lower right now). It will be interesting to see what useage will be in the tropics.
Now that we are preparing for a trip to the Caribbean, and we decided that we want a watermaker, I had to install something more substantial. Since my boat is only 31ft and I did not want an arc there was not enough space to permanently install sufficient solar power. We do not want to use the engine to charge so I am installing a 2 part power generation system:
When underway we will be using the smallest of the Watts&Sea units. This will probably generate more power than we will ever need. So when not charging we can just lift it up. I installed the unit removable so it will disappear down below when at anchor.
When at anchor we will be using 2x100W mobile solar panels that can also double as sunshades. The Watts&Sea comes with a 600W MPP regulator that also accepts solar input when not hydrogenerating. So solar can easily be upgraded when necessary.
Concerning the water maker we chose simply the smalest model we could find. The choice fell on the Katadyn PS-40E witch will be using about 4-5A. and producing about 5L water per hour. This model does not have any fancy electronics but a milspec number. It should be rugged enough for us I hope. Especially it is small enough to be used daily.
OK this system might be overkill for our small boat but it will make us almost selfsufficient. I’m still in the installation phase so I do not have any real word experiences yet, – but for now that’s the plan.

Dick Stevenson

Hi Enno,
I am sorry to have missed you in Norway last season. What is the name of your boat?
It sounds like a wise electrical plan. One question: Will your 31 foot boat be able to generate enough boat speed to make a W&S generator work. It was a few years ago, but I remember thinking that, at lower boat speeds, their output was fairly marginal. Maybe things have progressed?
The Katadyn should be a good choice. We have had a 160 for up to ten years now and been quite pleased For those with 2 water tanks and a bit larger boat (and $$), I recommend 2 of the smaller Katadynes such as you bought rather than one bigger unit. Use one one day and the other the next. Water is then good from the first drop generated. They are compact and easy to install and provide redundancy. The may use a bit more amps per gallon, but make up for that in their simplicity.
Good luck and let us know how the W&S works out when you have some mileage on it.
Dick Stevenson, Alchemy

Enno

Hi Dick
My Boat is called „Inua“ If you ever see her on AIS don’t hesitate to call us up. This summer and autumn we hope to be sailing south to the North Sea, and on via English channel, Biscay and Portugal towards the Canaries.
Theoretically the W&S should produce more energy than we can use. You can buy different propellers, optimized for different boat speeds. We bought the 280mm model for low speed boats. According to the specs we should get 120W (10A) at 5.5kn and 200W at 6.5kn. To reach full power (300W) we would need 7.5kn which is about hull speed. These are manufacturer specs. I am going to find out soon enough what it will be in reality. Should be enough though.
Why would you install 2 watermakers instead of one? I always thought that watermakers should run  as frequently as possible. Having two would put less usage on every single one, wouldn’t it?

Dick Stevenson

Enno,
I did not know about the different props for W&S. Makes sense. I look forward to your field reports.
I have cruised your proposed grounds and make harbor notes: info of interest and help to cruisers not generally available in the usual guides. I would be happy to send you a sample, and if interested, could send relevant notes which include many of the usual harbors on the Atlantic coast of France, Spain and Portugal in addition to most coastal spots in the UK.
I am happy to share. Write .
Dick Stevenson