At what Amp not worthwhile

[geem]

"typically 30-40% of time "sailing" is under motor"

Wow! You live in a very different world to me!
We are a sailing boat first and foremost. If I was motoring 40% of the time I would pack it all in. Sailing without a motor is one of the great pleasures in life. Being independent of a marina for me is an absolute must.

 

[Buck Turgidson]

Wow! You live in a very different world to me!
We are a sailing boat first and foremost. If I was motoring 40% of the time I would pack it all in. Sailing without a motor is one of the great pleasures in life. Being independent of a marina for me is an absolute must.

And it's absolutely impossible for most sailors who do not live on their boats and in some case not even in the same country as their boats ?

 

[Tranona]

Wow! You live in a very different world to me!
We are a sailing boat first and foremost. If I was motoring 40% of the time I would pack it all in. Sailing without a motor is one of the great pleasures in life. Being independent of a marina for me is an absolute must.

Exactly!. This estimate is drawn from many coastal cruisers log experiences. Some simple sums to help. Typical annual engine hours are between 100-150, so based n 100, annual hours under way is 300. 6 hour passages a day equals 50 days. Clearly some people do more but that is only a 2 week holiday and 13 weekends in a 6 month season.

Yes, a different world but that is more the majority regime rather than your sailing life, and perhaps why very little related to your boat and the way it is equipped that is relevant to most people on this forum - although not all and it is always interesting to read about other peoples' experiences.

 

[Neeves]

Exactly!. This estimate is drawn from many coastal cruisers log experiences. Some simple sums to help. Typical annual engine hours are between 100-150, so based n 100, annual hours under way is 300. 6 hour passages a day equals 50 days. Clearly some people do more but that is only a 2 week holiday and 13 weekends in a 6 month season.

Yes, a different world but that is more the majority regime rather than your sailing life, and perhaps why very little related to your boat and the way it is equipped that is relevant to most people on this forum - although not all and it is always interesting to read about other peoples' experiences.

Interesting

Not entirely relevant but:

Josepheline is a production yacht (catamaran) but they were building them one at a time when we contracted, we are hull No 10. Because the yachts were built individually there was opportunity for customisation, we had another head added in the other hull. We could have had dagger boards, we have mini keels. There were engine options and the added equipment, galley etc, was our choice. We have an inner forestay and a storm jib (I decided I was never going to have the courage to attach a trysail so we had a monster 3rd reef instead). We later added other equipment, desalinator etc. We were lucky as our build incorporated the reinforcing in the cabin roof to add Genoa tracks and extra winches (which we retrofitted - finding a self tacking headsail a waste of time unless its blowing 30 knots! (and who needs to sail in 30 knot winds and 4m seas - if you are cruising).

However in terms of safety we had her built to Cat 1 standards, not because we were going to race but because the specified safety equipment seemed sensible if we were going to cross Bass Strait or head up into the Coral Sea. Reading my links on storms, in the Med or the Scilly Isles (I know focussed for people at anchor) people do get caught out.

This was all a personal choice - even cruising yachts (or their owners) can be caught out and Biscay is a larger undertaking than Bass Strait - so I have to wonder why others don't have similar demands for their cruising yachts. Geem has equiped for long term living aboard and for crossing oceans - just move to the live aboard section of this forum - there are lots of owners in a similar position, or contemplating same - Geem is not alone. I don't see Geem's requirements for his yacht are much different to ours, or some of the other liveaboards.

A forum member making a circumnavigation contacted me 8/12 weeks ago - because he knew of me through YBW and I arranged for him to have a new, lightweight, high tensile rode made., 130m x 8mm instead of 10mm. He will collect it on the 4th July up north in Cairns. My ideas on lightweight rodes are shared Geem's ideas, to me, are not unusual, my ideas on lightweight rodes are not unusual. What might be unusual is the attention to detail.

Geem's ideas work - he does not run his engine to charger his batteries. My ideas work - I've supplied 5 rodes in the last 12 months (no - its not a commercial venture - I make no money - my wife reminds me - it costs us, but only pocket money which I lack the incentive to collect).

If someone wanted advice on kitting out a yacht to cross an ocean, or oceans I'd suggest they contact Geem (though I'm not sure he would welcome the attention). But if you kit out for an ocean - you are going to be equipped to cross the North Sea or Biscay (or sail round Great Britain). If you follow Geem's ideas on self sufficiency you will not need to run your engines - and annoy the neighbours. If you read and implement Cat 1 regs - you can have reduced fears over the safety of yourself, and maybe more important (your crew).

I read this thread and was left incredulous

Manslaughter Waiting to Happen

There were so many failures - were not doubts raised by scrutineers. It reminded me of Teignmouth Electron and/or Donald Crowhurst. It reminded me of lives lost on Clipper yachts possible because the equipment being used was inadequate and untested - don't people go on shake down cruises and test systems.....a lack of attention to detail.

Apologies to the OP - rather too much thread drift.

Take care, stay safe

Jonathan

 

[noelex]

Running engine for charge for battery. Sometime down to under 5A,(sometime over 40A) when do you decide not worfh running the engine for a paltry charge.

Adding even a small amount of solar is a help if this is feasible. The solar may not be enough to power your electrical demands, but solar and alternator charging complement each other. The alternator can supply a large amount of current quickly, but as the batteries reach around 80-85% SOC the acceptance drops off. The engine can be stopped at this stage and the remaining 15-20% is completed by a small solar array.

This way the batteries reach 100% SOC frequently, which helps their lifespan, but without a long engine run time where the batteries are only accepting a small fraction of the potential alternator output.

 

[noelex]

Especially if your charging is predominantly via the engine, fitting an external alternator regulator is worthwhile.

 

[Daydream believer]

Wow! You live in a very different world to me!
We are a sailing boat first and foremost. If I was motoring 40% of the time I would pack it all in. Sailing without a motor is one of the great pleasures in life. Being independent of a marina for me is an absolute must.

You might be a sailing boat, Mine is as well. However, I see no reason NOT to use the engine. Mine is quiet & helps avoid some difficult passages through lost tidal gates. It is there & I use it. Why ever not?
As for keeping away from marinas; I have anchored 5 times in 18 years & 4 of those were emergencies. The joy for me is not totally about the sailing ( Especially as I spend so much time being sea sick). I mostly enjoy the navigation The best bit is the departure & arriving. The visiting & exploring the places I go to. I still spend lots of my time tweeking the sails. But my biggest thrill is at the harbour entrance after a satisfying trip; whether it be under engine, sail, or both.

As for the percentage motoring. I was looking at 2 cruises to Camaret from the Thames estuary. On the first I only managed 14 hours pure sailing without the engine. The next was exactly the opposite. Quite by fluke I ran the engine the same 14 hours & that included entering & exiting ports. It was all down to the direction & strength of the wind. But both trips were memorable & I had no worries about using the engine. Who cares, I had great fun walking & cycling the French coast & Guernsey on my folding bike.

My round part of the UK trips , I totalled approx 30% engine use. Most of that was in the Caledonian canal & entering & exiting ports. With nearly 5000 hours on the clock, I may soon have to get a new engine. If i do I might upgrade from a Volvo 2020 to a 2030

 

[fisherman]

Seems to me that engines became useable when small diesels came along, before that it was a Stuart Turner, Brit minor, Morris Vedette, RCA Dolphin, or a socking great Lister, Petter, or a chuffing 1908 Kelvin. Carrying enough petrol for meaningful passage making was a problem, paraffin as well for the Kelvin. Much more useable now.

My first post here in 2005 was to ask if yachts passsing me off the Lizard could possibly fly a motoring cone, as I hardly ever saw one under sail alone. (That went well, cue seventeen fishing signal rants).

 

[Tranona]

Interesting

Geem's ideas work - he does not run his engine to charger his batteries. My ideas work - I've supplied 5 rodes in the last 12 months (no - its not a commercial venture - I make no money - my wife reminds me - it costs us, but only pocket money which I lack the incentive to collect).

That was my point. When I specified my Bavaria everything was focused on making it usable for me, hence the bow thruster, additional winches, upgrades for sail furling, remote controls for windlass and thruster. Keeping a boat in a marina means no excuse for the batteries being neglected - just plug in when you get back from a trip. If on a swinging mooring a solar panel does a similar job of keeping the batteries topped up during the week.

It is all about identifying what you need to achieve your sailing objectives and equipping your boat accordingly. I mentioned the small number of solar equipped boats in our club. Was not always like that, but five years ago all the pontoons were replaced and electricity added. All the plug in solar panels many people used disappeared overnight and replaced by shoreower leads!

With my first boat in Corfu, even though there is lots of sun we had no solar. The boat was on charter and in the main season there is no wind in the morning and a few hours in the afternoon and early evening. So every morning meant 3-4 hours motoring to the lunchtime stop - just right to keep the fridge and beers cold and heat the water for the post swim shower and top the batteries up for overnight usage. 200Ah bank was more than enough. at the end of the week plugged into shorepower. Engine hours averaged 500 a year - that gives a lot of electricity and hot water. If we had kept the boat out there I would have added a gantry and solar, plus a bigger house bank so that we could have been independent of the shore for longer and anchored rather than going alongside a quay.

Different requirements, different solutions.

 

[Refueler]

I never really understand, but am told the alternator is designed to put in a quick top up charge to replace start current in a car, and can only charge a battery to about 75%, although it will say it is full. My friend installed Adverc, his engineer said very unusual to see a battery so comprehensively charged, 95%+. I believe a generator, as fitted to cars in the olden days, or portable etc, will do the job, as will solar or wind.

I only had a 40 amp alt in my boat. No point having bigger, the total draw could only reach 32A. The problem is it needs to get to about 3000rpm, so if the engine was under 1000rpm the current declined, so having 70A or 100A no point.

Thats my info as well .... Alt's do not charge to 100% .....I was told about 80 - 85% ....

Pal of mine just changed his Alt from the usual 40A jobbie to a 90A version on his Yanmar ..... any difference ?? Because he's based in Club and has mains charging etc, - no benefit. But if he ever cruises and lacks shore facility - then hopefully that alt will charge his batterys a bit quicker .... but with all said and done .... my standard Alt on my 4-107 ... 50A ?? keeps my two batts up on cruises...

Each to their own .....

 

[Refueler]

Seems to me that engines became useable when small diesels came along, before that it was a Stuart Turner, Brit minor, Morris Vedette, RCA Dolphin, or a socking great Lister, Petter, or a chuffing 1908 Kelvin. Carrying enough petrol for meaningful passage making was a problem, paraffin as well for the Kelvin. Much more useable now.

My first post here in 2005 was to ask if yachts passsing me off the Lizard could possibly fly a motoring cone, as I hardly ever saw one under sail alone. (That went well, cue seventeen fishing signal rants).

Dont forget the old Vire !! Literally a Moped engine !!

 

[Alex_Blackwood]

Thats my info as well .... Alt's do not charge to 100% .....I was told about 80 - 85% ....

Pal of mine just changed his Alt from the usual 40A jobbie to a 90A version on his Yanmar ..... any difference ?? Because he's based in Club and has mains charging etc, - no benefit. But if he ever cruises and lacks shore facility - then hopefully that alt will charge his batterys a bit quicker .... but with all said and done .... my standard Alt on my 4-107 ... 50A ?? keeps my two batts up on cruises...

Each to their own .....

To keep it absolutely simple, no fancy physics, if an alternator regulator is designed to give a voltage of 14.5 volts, and is battery sensed. It will continue to put current(amps) into the battery at an ever decreasing value until the battery voltage reaches 14.5 volts at which point there is no potential difference so no current will flow. If the battery is connected to an output of say 60 watts then 5 amps will flow. the alternator will maintain this flow and the battery, in effect, becomes an Uninterruptable Power Supply (UPS). At this stage the battery is "Floating" with the alternator providing the power. The alternator will charge the battery up to a voltage determined by the regulator, the sensing and the losses in the circuitry.

 

[geem]

[/QUOTE]

Adding even a small amount of solar is a help if this is feasible. The solar may not be enough to power your electrical demands, but solar and alternator charging complement each other. The alternator can supply a large amount of current quickly, but as the batteries reach around 80-85% SOC the acceptance drops off. The engine can be stopped at this stage and the remaining 15-20% is completed by a small solar array.

This way the batteries reach 100% SOC frequently, which helps their lifespan, but without a long engine run time where the batteries are only accepting a small fraction of the potential alternator output.

This is exactly how we were set up years ago when sailing in the UK. Solar is very effective for that last part of the charge cycle as you say

 

[noelex]

For those interested in charging predominately via the engine some of the recent developments have been particularly helpful.

It is now possible to fit high powered alternators on most marine engines and this, combined with a smart alternator regulator and preferably lithium batteries, means considerable amounts of energy can be recovered in a short time.

Producing 2kw or more is quite feasible especially for larger boats.

 

[Tranona]

This is exactly how we were set up years ago when sailing in the UK. Solar is very effective for that last part of the charge cycle as you say
[/QUOTE]
See post#29. Many people in the UK do exactly that with boats on moorings, but if you are in a marina with shorepower then just plug in.

 

[Birdseye]

Wow! You live in a very different world to me!
We are a sailing boat first and foremost. If I was motoring 40% of the time I would pack it all in. Sailing without a motor is one of the great pleasures in life. Being independent of a marina for me is an absolute must.

We each make our own choices. Being a saddo, I kept a log of engine use over two years cruising and found that the engine was on just under 50% of the time that our boat was off its moorings. Mostly that was because passage making involves deadlines with weather and tidal gates - get the tides wrong in the Bristol channel or off Ushant and you can end up sailng backwards. I've done it

Its a bit like the issue of helming. I enjoy pure sailing and helming when racing but passage making the engine is on if we drop below 4kn and the autopilot is on as we leave the harbour. Thats our choice.

 

[Birdseye]

For those interested in charging predominately via the engine some of the recent developments have been particularly helpful.

It is now possible to fit high powered alternators on most marine engines and this, combined with a smart alternator regulator and preferably lithium batteries, means considerable amounts of energy can be recovered in a short time.

Producing 2kw or more is quite feasible especially for larger boats.

Lithium batteries are a different and expensive game. What follows is about lead acid.

There is some alternator salesmans puff in the above. The current flow into your battery bank is governed amongst other things by the difference in voltage between the alternator output and the battery voltage. Half charged battery 12.2v alternator 15v current is a function of 15-12.2) So provided your alternator is big enough to charge at maximum, it doesnt matter if its rated at 60w,80w, 200w - the current flow will be the same. But raise that voltage over 16v or so and you will end up boiling the battery so there is a limit to how much current you can put into a battery by using a regulator to raise voltage. Not only that but the state of your battery, how charged it already is, will decide how much you can pump in. So you might start off with 40 amps from your 60 amp alternator ( I never recorded more than that even with a smart regulator) but you will still find that current dropping off over time.

None of the above is to say that you cannot improve your current set up a bit with the best kit, but simply to say that basic physics limits what you can do.

The result of this is that to charge a battery bank from half full to full is going to take some hours engine running.

 

[fisherman]

daughter has Li on in her van, ashe lives in it and works translating online. Large solar panel, exotic charging system, about £900 all in. Very good, but she still has to plug in occasionally if it's dull or she hasn't driven anywhere.

 

[William_H]

The comments about alternator voltage sensing versus battery voltage sensing might be a bit misleading. Yes there will be a voltage drop in wiring and switches but this is resistive. (assuming no splitter diode in circuit) Resitive means that voltage drop depends on current flow. So yes max current might be slightly limited (depending on resistance of wiring etc) but volt drop will fall with current so that battery ends up at alternator voltage due to low current. So in the end alternator sensing will not be much worse than battery sensing in terms of getting batterry to full charge or in how much you get in with limited engine run time. ol'will

 

[noelex]

So provided your alternator is big enough to charge at maximum, it doesnt matter if its rated at 60w,80w, 200w - the current flow will be the same.

I presume there is small typo and you mean amps not watts.

True, but how big is big enough? If you want lots of energy in quickly you need lithium. Even a relatively small lithium bank will take in the output from even a very large alternator. This option should not be dismissed. It is the best solution if you rely on predominately engine based charging and it is suitable for all sized vessels.

However, a large lead acid bank will also accept the output from even a relatively large alternator until it reaches a charge state of around 85% full. We have a large lead acid bank. It will accept over 2Kw until the state of charge reaches a high level. This requires a large alternator to charge quickly, especially when it has to supply house loads as well.

Your caution is valid for a small lead acid battery bank, but this is really not the right solution if you depend primarily on engine based charging unless your electrical needs are very modest.

One important thing to understand is that most stock marine alternators drastically cut back their charging as they heat up. The alternator on our previous boat’s Yanmar engine was typical in this way. Although it was rated at 80A, as it heated up the maximum it would deliver, irrespective of battery voltage or house loads was around 40A. Many people mistakenly believe that their diminishing alternator output is always due to reduced battery acceptance when in reality it is often insufficient output as the alternator heats up often combined with excessive voltage drop and incorrect voltage regulation from the internal regulator.

The result of this is that to charge a battery bank from half full to full is going to take some hours engine running.

True, but if you have a lead acid bank and are running the engine to charge the battery, aiming for 100% full is not the right strategy. You need to stop at around an 80-85% state of charge while the battery acceptance it still high.

If you are running the motor for long periods to provide propulsion then the battery will eventually reach 100% SOC, especially if you have an external regulator that is delivering the correct three stage charging. If you consistently do this then generating sufficient electrical power should not be an issue. If this is your usage patten (and there is nothing wrong with this), even a relatively small alternator will be sufficient, but if you only typically motor for a short period in and out of an anchorage, as we do, there are better options.


In summary not all boats will significantly benefit from a large alternator, but to dismiss this option as “alternator salesmans puff” is wrong.

Alternator technology has improved enormously recently. Models that can deliver high continuous outputs are now available. These are a vast improvement from typical marine stock alternator that might have a reasonable output on paper, but in reality can only deliver a fraction of this promised energy.