Lack of power on board when cruising

[Robin]

House battery capacity is 280ah and another 80ah for the engine. The fridge is one of the super efficient Isotherme water cooled ones - uses about 2.5a per hour when on - even so do not run all the time. Biggest user is the E120 chartplotter at about 7 a/h. The Mastervolt battery gauge is really good, lets you see what everything is using and allows you switch things on/off to maximise battery life. For the first week out from the marina shore power there is little problem in keeping the batteries up at 80%+, abet after some motoring. It's in the 2/3 rd week away from shore power that the engine needs to be run longer, also power usage more carefully managed.

I do not like the idea of hanging a windmill off the boat - don't like the look of it - no matter how practical it may be. From all the feedback looks like I will go with the Sterling Alternator to Battery charger.

Thanks everyone.

To add to what others have said:-

Firstly you need to accept that with a house battery of 280Ah you only have 140Ah available and that is only if the battery starts at 100% charge and is brand new so not lower capacity anyway. Then you have to accept that in reality away from smart shorepower charging, you cannot get batteries up to 100% by engine alternator and standard regulator, and even with a 'smart' one the last 20% of charge takes some time. Then having accepted all that, your battery capacity available in reality is from 80% to 50% or in the 280Ah battery it gives you just 84Ah to use.

Now that you know you only have 84Ah available in practice, you need to look at how to seriously increase that capacity, then how to replace what is used and what with. We were totally self sufficient on our last boat with around 700Ah of house batteries, a fixed 75W solar panel and a 120W one that came out for more than a couple of days at anchor. We also had a big Aerogen6 wind gen, but mostly that was tied off as the solar panels were quiet and adequate. We didn't have the portable gennie on board even, noisy things, yuk. We did have 2 alternators on our (44hp Yanmar) engine both with Adverc smart chargers as we had our service batteries in two banks, in addition to the engine start one.

On the other side of the equation you need to look at your power consumption and what is using the power. To my mind BTW, if you turn a fridge off to save power as many do overnight then you don't have a fridge anymore, it has become merely a cool box. What is the 7A for the plotter? Is this running all the time or what, that is massive. Does it include radar, if so why is that running all the time?

Then look at additional charging. A 1KW portable generator should run a decent smart charger. We had a Sterling Pro charger that could be downrated to 75%/50%/25% output so as not to upset a small generator or trip some marina breakers. Solar is good, even up north in summer because the lack of sun is compensated somewhat by longer hours of daylight. Wind is good too.

Fridges need to be properly insulated, few are as supplied although our last one on a Jeanneau was surprisingly good and was a 210L size. We had some polystyrene blocks I cut and covered with aluminium foil in the bottom part to close off an unused bit under the baskets. For shorter term use like weekends, we would bring a 1lt bottle of water frozen at home to put in and help because the fridge wouldn't be full. It takes a long time to cool down a fridge from first start too, especially if there is lots of liquid stuff like cans or bottles left routinely on board in the fridge.

Food for thought maybe.

 

[snooks]

What Robin said ^

For plotter frugality turn the brightness down...you don't need it at 100% brightness all the time

Less bright = Less power = Happy Kyleview

 

[Robin]

I don't understand 7A for a plotter unless that is also displaying radar. So turn the radar off under sail unless it is needed. As Snooks says turning the brightness down on the plotter too will help. I take it the plotter isn't left on 24hrs a day because I know some do that to provide an anchor alarm? I reckon with the current setup, the boat has 84Ah usable power which in fact is only 12hrs of that quoted plotter consumption just on it's own!

 

[Bosun Higgs]

We have been away 4 weeks up the West coast of Scotland - on anchor and moorings before going into Tobermory after 3 weeks to top the batteries up from shore power by which time we were struggling to keep the batteries above 60% charged. We have a pretty new boat equipted with Mastervolt AC/DC charger, also their battery monitor to see whats happening - a pretty big "drain" each day from the electronics even with the fridge/radar run sparingly, the heater not at all, and the computers / phones / etc charged off a 1KW Honda portable generator. Bottom line is you need to motor every day for a few hours to keep things "alive" which is a real pain.

Have been looking around and have decided that a Smart Regulator on the alternator is the thing to fit but all brands look complicated to install and you need to get into the alternator (warranty voided) - cheap, but difficult overall. I am now looking at the Sterling Alternator to Battery Charger - AB1280 - more expensive, but looks a lot easier to install, also less change to what's already there. Has anyone got experience of this piece of kit, how good is it, does it do what it claims, and how easy is it to install.

http://www.sterling-power.com/products-altbatt.htm

Any input appreciated, also other suggestions. I really need to do something over the winter to make cruising more relaxing in the future.

If nothing else, you're not alone.

I fitted a sterling digi regulator and it helps - but it's not the answer. It isnt that difficult to fit by the way but all it does is to reduce the number of hours you need to run to fully re-charge your batteries. It doesnt do away with the need to run your engine. And incidentally, it does cause the alternator to run at full output which in turn gets it very hot. So hot that I have to use oven gloves to open the metal catches just above the alternator.

I have tried windmills as another way of generating leccy. You need a big one to produce enough to make a difference and they can be noisy - not only the whistling noise but also noise transmitted through the structure of the boat. Its a choice here of 24 hr low level noise nuisance of the windmill compared to 1 hr of high level noise from the engine. And they really are ugly things to hang off the back end of a pretty yacht.

I have a solar panel. Its a fair size ( something like 40 inches by 20 inches) but at best it produces 2 amps and thats for part of the day. I worked it out at something round 15aH per 24 hrs but a recent article in one of the sailing mags would give you a better idea of what you might expect. Either way it doesnt begin to touch the 50aH or so that we consume each day, and to get that mush would require a significant area of ugly solar panels on some sort of bent metal gantry. Not willing to do that.

I have a pal who has a genny. Have to say that that is the best answer. Leccy for the toaster, hot water for the shower and its really quite quiet.

I hope this is some help even if I cant offer you a simple solution. Certainly, the digi regulator will speed up the charge but even with that it still takes up to 5 hours** for my 60 amp alternator to re-charge the 2x110aH service batteries fully and to drop back to maintenance level. Thats according to Sterling themselves who insist that you likely will never get to fully charged on a standard alternator. And since all the alternative regulators work in the same way they have the same problem. So in my view the key is a/ a built in genny and b/ some serious work to reduce your leccy useage. It does sound a lot if you are not using the fridge very much. What "electronics" are you using at anchor?

An alternative might be a big alternator ( say 120 amps), a digi regulator, and a couple of 60 watt crystal solar panels on a tilting frame. At least solar is quiet.


** For those inclined to argue the logic goes - 2 x 110aH batteries drained by 3/4 requires 165aH to recharge which means something like 190/200aH from the alternator. At 60 amp output that would be 3 1/2 hours. But the output isnt 60A for the full charging time even running at 14.4v ( I have a sealed battery in circuit) and it gradually tails off as the batteries get near fully charged. Imagine how much longer it will take with a standard regulator dropping back to 13.5v after a short time.

 

[Robin]

** For those inclined to argue the logic goes - 2 x 110aH batteries drained by 3/4 requires 165aH to recharge which means something like 190/200aH from the alternator. At 60 amp output that would be 3 1/2 hours. But the output isnt 60A for the full charging time even running at 14.4v ( I have a sealed battery in circuit) and it gradually tails off as the batteries get near fully charged. Imagine how much longer it will take with a standard regulator dropping back to 13.5v after a short time.

That will be me then!

If you routinely discharge your batteries BY 75% you will need to open an account with the battery supplier unless you have really high quality deep cycle batteries which very few so called deep cycle batteries are - think golf cart batteries not the usual leisure ones.

So in your case with 2 x 110Ah you actually only have 110Ah available by keeping discharge to less than 50% (about 12.2V lowest) 110Ah used will need maybe 140Ah returned by charging because it isn't 100% efficient. However the last 20% of charge takes several hours at low amps but raised volts and is a waste of time trying to do by engine, or generator running for that matter, plugged in to AC shorepower is different. The sensible time to stop running a generator or engine system is at 80% charge, the point at which the (smart) regulator will have dropped it right back. So on your 2 x 110Ah batteries your useful capacity is from 50% (110Ah) to 80% (176Ah) so just 66Ah actually usable IF your battery is still 100% capacity capable which is very doubtful as they all deteriorate with age/use. On that basis you should be able to go to 80% by putting back 66Ah + another say 40% for efficiency loss, so about 92Ah and maybe 2 hours of engine running. The battery capacity as well as the regulator will determine how many amps the alternator puts out and it will drop as the battery gets nearer full.

Also your alternator sounds like it is running too hot, not a good idea unless you have a good stock of spare ones. Between the battery shop and the alternator shop you could be providing some serious contribution to the economic recovery!

We had one fixed 75W solar panel on a gantry, but also carried a bigger one of 120W (it would put out up to 7A in the middle of a summer sunny day) that we just laid on deck when needed. This was more efficient than the fixed one because we could move it to avoid shadows a couple of times usually per day.

The key too is to have enough battery capacity to take a charge, it is a bit like filling water tanks from a rain collector, it is wasted if the tank is too small to take more when it is still raining.. Also bigger batteries will take and demand a higher alternator output for longer before being reined back by the regulator.

So, put some decent sized batteries on board, add a solar panel and wind genny, then see how your racing results/handicap changes!

 

[pvb]

Also bigger batteries will take and demand a higher alternator output for longer before being reined back by the regulator.

These battery threads are characterised by comments like that. A regulator doesn't "rein back" the alternator's output. All the regulator does is set the max output voltage of the alternator. It's the ability of the batteries to accept the charge which reduces as the batteries approach their charged state.

 

[pvb]

I had also noticed the un-boosted output for the starter battery - a feature I like. Also it made me think that if I had just gone for a smart alternator regulator I could have had problems with the starter battery as it's a sealed one and different to the house bank. Do you know of any "hidden" surprises with the Alternator to Battery Charger that I should be aware of before proceeding? Thanks

You probably wouldn't have had problems with the "sealed" starter battery - the maintenance-free lead-calcium batteries are fairly resistant to high charging voltages.

Don't know of any surprises with the AB1280. You haven't said how big your alternator is. It might be worth getting the next model up (AB12130) as it's only a few quid more and might run a bit cooler perhaps.

 

[Robin]

These battery threads are characterised by comments like that. A regulator doesn't "rein back" the alternator's output. All the regulator does is set the max output voltage of the alternator. It's the ability of the batteries to accept the charge which reduces as the batteries approach their charged state.

Sorry, yes agree fully, mea culpa and badly worded, but I was trying to describe the view simply and as seen from the users point of view looking at the on board meters if he has them. Maybe what I was trying to get across is that a combination of things are needed to improve matters not one single one, like a bigger alternator is no good (or little advantage except running cooler maybe) unless the batteries are bigger and both really need an upgrade from the standard regulator.

Did I get anything else wrong?

 

[pvb]

Did I get anything else wrong?

Well, I didn't bother to question your statement "The sensible time to stop running a generator or engine system is at 80% charge, the point at which the (smart) regulator will have dropped it right back." But I'm not sure what you mean by it!

 

[Robin]

Well, I didn't bother to question your statement "The sensible time to stop running a generator or engine system is at 80% charge, the point at which the (smart) regulator will have dropped it right back." But I'm not sure what you mean by it!

Because getting that last 20% of top up charge squeezed in when the amps are lowered (OK by the battery voltage getting up closer to the regulator setting rather than the regulator controlling it as you pointed out) takes disproportionately longer engine or generator running time compared to getting most of the capacity used replaced. That time matters little if plugged in to shorepower with a decent smart charger but it does matter in the peace and quiet of a nice anchorage. Also matters little if motoring for hours underway either, but then my comment related to being anchored up for a day or three.

I'm trying to relate to what most cruisers wants when away from the dock and I suggest that is the ability to run all the stuff they want to without wrecking the batteries and being able to replace what they used by the shortest, cheapest and quietest means possible. We achieved that in our last two boats, the first took a long time, the second came part way to nirvana on purchase but still took us two years to correct some (professionally installed) defects and to achieve it fully.

We now have a new venture in the form of a mobo, but unlike most it is fitted with 440W of solar power, 2 x 160A alternators with smart regulators and an 8KW generator running AC into one 120A battery charger and into another 40A one for the (two engine and one gennie) start batteries. The batteries are ginormous golf cart ones of which we have eight. On the other side of the power equation we have a fridge/freezer, a separate freezer and an ice maker that will run on 12VDC as well as AC power and the electric stove has been replaced with a propane one. Sadly the microwave/convection oven are AC not propane! We also have a 2,500W inverter. The boat spent 3 months cruising the Bahamas, Exumas and Abacos and always anchored out, but the only generator time over three months was for a few unbearably hot nights when the three air conditioning units just had to go on for a while.

I hope I got all that right but it is why I feel I have some useful input to make in replying to the original posts.

 

[Malcolm3]

Honda

I used a Honda and a Skyla control to stop the initial charging load and adjust it.

 

[kyleview]

I don't understand 7A for a plotter unless that is also displaying radar. So turn the radar off under sail unless it is needed. As Snooks says turning the brightness down on the plotter too will help. I take it the plotter isn't left on 24hrs a day because I know some do that to provide an anchor alarm? I reckon with the current setup, the boat has 84Ah usable power which in fact is only 12hrs of that quoted plotter consumption just on it's own!

Radar scanner off and plotter only used when on the move - turned off within 5 minutes of arrival! The E120 I think has only 2 brightness settings - day and night. Even at dusk the screen is hard to make out with the night setting , let alone during the day. Maybe there are other dimming controls - input appreciated. The current draw is not surprising considering the amount of electronics packaged in it, also a reflection of the heat coming off - and by no means is most of that coming from the LCD panel backlight (even if not LED's). For anchor alarms the depth sounder is used, having the E120 on all night is unthinkable.

 

[pvb]

The E120 I think has only 2 brightness settings - day and night. Even at dusk the screen is hard to make out with the night setting , let alone during the day. Maybe there are other dimming controls - input appreciated.

The "night" and "day" settings only change the colour palette of the display. The backlighting level is continuously variable - see manual.

 

[noelex]

Radar scanner off and plotter only used when on the move - turned off within 5 minutes of arrival! The E120 I think has only 2 brightness settings - day and night. Even at dusk the screen is hard to make out with the night setting , let alone during the day. Maybe there are other dimming controls - input appreciated. The current draw is not surprising considering the amount of electronics packaged in it, also a reflection of the heat coming off - and by no means is most of that coming from the LCD panel backlight (even if not LED's). For anchor alarms the depth sounder is used, having the E120 on all night is unthinkable.

The E series do draw a lot of power.
I do not know what sort of sailing you do, but a GPS with just a small B&W screen may be worth considering in addition to the plotter.
I have a Furuno GP32 it only consumes 0.2A with the backlighting on. The other option is handheld wired into the 12v supply such as the Garmin 72H.
This will give you a GPS anchor alarm and a back up GPS. Plotters are nice to have, but there are many occasions when they can be turned off. Even costal sailing when the nearest shallow patch is a couple of hours sailing away, you can turn the plotter off for hour and use the small low power GPS to provide all the information you need, distance and bearing to go to the waypoint SOG etc.

 

[snooks]

The E120 I think has only 2 brightness settings - day and night. Even at dusk the screen is hard to make out with the night setting , let alone during the day.

RTFM - Read the flippin' manual

Those are the pallette settings.

The brightness is the screen brightness. Press the power button quickly (not the long press to power down), then turn the twiddly knob anticlock wise or use the left arrow to move the little blue bar to the left to reduce the screen brightness.

Only in direct bright sunshine do you need the full brightness

 

[lustyd]

If you get 5 years use out of a rechargeable Lithium battery then you are doing quite well, and the storage life is not much better either...

+1 on this, mobile phone batteries are Lithium based, and have the ideal usage pattern for a Lithium battery (use every day, charge every night). These HALF in capacity in a year.
Now translate that to your boat battery which gets used twice a week maximum, probably significantly less on average, with an irregular charging pattern. This will not lead to a good life for the battery. Electric cars using this tech are designed with the daily commute in mind, so are similar to the phone usage pattern but these too have a 5 year life according to Top Gear.

 

[Barnacle Bill]

Maybe not the answer you want, but having tried both options I now prefer the low power usage route.

There must be somewhere next to the hull below the waterline where you can store a few cans of beer! (Very acceptable temperature in Scotland).

Hand-held GPS (AA batteries) for nav. That only leaves nav lights, and personally I'm investigating the LED option for those.

On the other hand ... I've had 2 alternators destroyed by smart chargers, installed a fridge and freezer system that needed to be replace after 4 years (and caused considerable confusion when the water inlet was blocked by a jellyfish), dealt with faulty and flooded generators, had to carry a spare shore-power transformer on board ... nightmare! Too many systems!

 

[kyleview]

RTFM - Read the flippin' manual

Those are the pallette settings.

The brightness is the screen brightness. Press the power button quickly (not the long press to power down), then turn the twiddly knob anticlock wise or use the left arrow to move the little blue bar to the left to reduce the screen brightness.

Only in direct bright sunshine do you need the full brightness

Thanks for the advice - much appreciated. You learn something everyday on Scuttlebutt which makes it so good.

PS - the flippin' manual is rather over the top and complicated, even the TEN+ page summary! Pressing the power button quickly gives me the pallette change which I thought was the brightness change - so I never explored further thinking that was all that happened !!!!

 

[Tintin]

I have no experience of the Sterling unit.

What I did woz.....

a) fit an adverc unit (but the company has since imploded and the good staff left to start Adesas - google should find them - Jenny is great) - it isn't as complicated as it seems and the phone and email help was stunning.

b) fitted a 90a alternator instead of my old 35a one - supplied by Adverc (Adesas do the same) pre-moded and covered by guarantee despite mod.

c) fitted 3 x 110ah bog standard leisure batteries - I figured that spending twice as much on Gucci batteries wouldn't give me twice as much life or time between charging

d) Thought about solar, what it would give me, what space I had, and the cost per amp, and ditched that idea.

e) Thought about wind, decided it was no better than solar for the charge I would get and needed more hard earnt £££'s, so ditched that.

f) Decided that the cost of a small amount of diesel each day to charge was easily afforded compared to cost of solar and wind.

g) And as this was all fitted to a 7hp old volvo engine, Jenny (now at Adesas) suggested two very simple switches so that when I needed full engine power I could switch out either the Adverc, the alernator, or both.

And it all works peachy.

 

[snooks]

PS - the flippin' manual is rather over the top and complicated, even the TEN+ page summary! Pressing the power button quickly gives me the pallette change which I thought was the brightness change - so I never explored further thinking that was all that happened !!!!

Raymarine manuals have never been renowed for their simplicity

This seems to be a case in point, look in the reference manual for how to adjust the brightness, if nothing jumps out in the 14 pages of contents, go to the index...is it under:

B for Brightness?
S for Screen Brightness?
D for Display brightness?
Or B again for Back lighting?

N it's under L for "lighting" on page 19