Lack of power on board when cruising

[kyleview]

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.

 

[Bodach na mara]

I fitted a Sterling Smart Regulator several years ago. I will not say it was easy, but I managed, and I tend to think for ages about a job before I actually get on with it. During the first season, the regulator failed and I cannot fault the response of Sterling. I returned the unit to them and got back almost by return post a new one, which was a new improved "digital" one, at no charge.

I now get a steady 30 amps from the alternator (I have a 24 volt system) for up to an hour or until the batteries (two banks of 50 and 80 Ah) are near charged. This has certainly meant less need to charge, but has not eliminated it completely. The 80 Ah domestic bank can power the fridge, lights and pumps for two days in summer, but it all starts to get a bit dim during the second evening and the battery protection unit on the fridge cuts it out on the third morning. I really need to run the engine for a while every second day. It does get annoying having to motor when there is a good sailing wind.

 

[pvb]

The Sterling Alternator to Battery Charger is a clever product, very easy to install as long as you follow the instructions carefully. It would certainly increase the charge efficiency. One advantage it has over ordinary alternator boosters is that it has an un-boosted output for the starting battery, to avoid ovrercharging it. It also, of course, fulfills the role of a diode splitter as it isolates the start and domestic batteries.

You should also look at increasing the size of your domestic battery bank. A larger bank will accept charge more easily, and will not (for a given consumption) result in such a low depth of discharge.

 

[dylanwinter]

fridges and power

I assume that fridges eat power

on the slug things run much better now that I have abandoned fresh milk and started drinking warm red wine.

bacon keeps forever, sausages come from tins, the bilges are easily cool enough for cheese, butter, eggs etc.

Fridge drain problem solved -

The GPS runs on AAs

led lights sip power

candles are romantic

although I have to say laptops and camera batteries do need charging

Dylan

 

[Blueboatman]

Solar and wind gen would help enormously to offset the net drain on batteries, a keelcooled fridge prob too- and a towel folded over the toploading door at night, and or the odd bag of ice for a pound from supermarket, radar on standby . If using a generator anyway why not plug the shorepower into it to charge batteries simultaneously?

 

[Woodlouse]

Lithium batteries are the answer. You can drain them right down to zero, which means you don't have to charge so often, and then when you do you can have them charged back up to full within a couple of hours. They're an expensive initially but after you've bought them they'll only save you money. Next time my batteries need replacing I'll be ditching lead acid, purely because of the improved charging times. It'll be nice only having to run the engine an hour a week out of necessity instead of the four or so it takes to charge now.


Personally I don't run a fridge, the bilges keep everything cool enough. Except milk, but UHT solves that little problem. I use paraffin lamps for light and ipod speakers running off the 12v for music, which, along with very occasional use of lights, is my only drain.

 

[[2574]]

Calder offers good background guidance....

....to this subject, that of matching demand to resource etcetera. I read and re-read his book until I thought I had a sufficient grasp of the subject to make sensible decisions. I then uprated battery capacity to 600AH (520 domestic, 80 engine start) in three AGM batteries. I then fitted a high capacity Balmar alternator (120A peak) allied to a Balmar Maxcharge four stage (temperature sensing) regulator. I also fitted 150W of solar panels. Topping that off with a 70A charger/1500W inverter (with load balancing) from Victron. I also swapped all halogen and filament bulbs for LED's.

I now find that when at anchor we can be entirely self sufficient in power on what I would describle as "normal" English summer conditions. That includes fridge drain and normal other "stuff" which inevitably one has on a cruising boat. In clear blue sky we have surplus solar power.

My thinking was to minimise engine charging (if at all) with the solar panels. If we had to use the engine (dull weather, no solar) then shortest time possible hence AGM's for high charge acceptance and big alternator to bang in charge as fast as possible.

The large charger was so that in the event of a deep discharge the batteries could quickly be replenished from shore power supplies. The load balancing inverter feature is a nice by product of the system.

The whole system works well. It wasn't cheap, but I can't bear to stand the noise and fumes of the engine just to charge batteries. It was worth it for me but I accept that some might consider it OTT.

Rob

 

[kyleview]

Solar and wind gen would help enormously to offset the net drain on batteries, a keelcooled fridge prob too- and a towel folded over the toploading door at night, and or the odd bag of ice for a pound from supermarket, radar on standby . If using a generator anyway why not plug the shorepower into it to charge batteries simultaneously?

The Honda 1KW works ok into the shorepower when the batteries are at 80%+ to add a bit. Much lower it struggles and starts showing the red warning light.
Unfortunate, but fact!. Thanks.

 

[davidej]

Lithium batteries are the answer.

Yes - but aren't they £K each? I seem to remember seeing a 110Ah advertised for something like £4,500.

 

[Woodlouse]

Yes - but aren't they £K each? I seem to remember seeing a 110Ah advertised for something like £4,500.

It's hard to find prices, but I remember reading that a Li battery is about 3x the cost. But the battery its self will last about 3x as long (that is the life of the battery, not the discharge time).

 

[kyleview]

The Sterling Alternator to Battery Charger is a clever product, very easy to install as long as you follow the instructions carefully. It would certainly increase the charge efficiency. One advantage it has over ordinary alternator boosters is that it has an un-boosted output for the starting battery, to avoid ovrercharging it. It also, of course, fulfills the role of a diode splitter as it isolates the start and domestic batteries.

You should also look at increasing the size of your domestic battery bank. A larger bank will accept charge more easily, and will not (for a given consumption) result in such a low depth of discharge.

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

 

[ChrisE]

You don't say how big your battery bank is.

We have 3x110ah, 1 nominally for starting and 2 for domestic.

We run a fridge, radar, autopilot, nav lights, etc and all the other stuff you mention.

With a Sterling Smart charger AND a big alternator (100 thingies instead of 60 thingies, don't ask me Beta specified it for us) we are self sufficient with a maximum of 1 hours engine hours a day. That's a figure over the last 6 years of cruising.

 

[V1701]

Fridge is a massive drain, could you improve the insulation, what type is it? LED lighting (I use Sea Rolf), more domestic battery, solar power (cheap monocrystalline panels from ebay are good, e.g. £95 for a 40W panel)...

 

[snooks]

Solar wouldn't be a great deal of help, you're a bit too far north for them to be fully effective....oh and the also need sunshine!

A wind gen might help, but you don't say what capacity your house batteries are.

We had power problems when we were up in Scotland, it turned out to be the alternator was dying. We got a more powerful replacement and it was happy days from then on.

We'd usually find a day of motoring (when there was no wind) was enough to get the batteries up to 100%.

A few more hints on fridge usage, open it as few times as possible for as shorter time as possible. Keep it full up, air looses heat fast, bottles of beer don't.

 

[ianc1200]

We have the Sterling alternator to battery charger (the one for 210amps) does seem to do what it says it will, but the disappointment is having two alternators total output 200amps, we see much tailing off of output so often seeing only 10 amps going in when 80% charged. We have fridge and usual domestics, inverter etc, and 440 amphours domestic bank, & 60W solar panel. Would say still about average engine running of a hour per day to keep reasonably topped up.
Best bit of kit we have is the "Smartguage" simple to fit and really lets you know the battery situation.

 

[Twister_Ken]

Keep it full up, air looses heat fast, bottles of beer don't.

No, but I do find the contents of the beer bottles tend to disappear.

 

[kyleview]

Solar wouldn't be a great deal of help, you're a bit too far north for them to be fully effective....oh and the also need sunshine!

A wind gen might help, but you don't say what capacity your house batteries are.

We had power problems when we were up in Scotland, it turned out to be the alternator was dying. We got a more powerful replacement and it was happy days from then on.

We'd usually find a day of motoring (when there was no wind) was enough to get the batteries up to 100%.

A few more hints on fridge usage, open it as few times as possible for as shorter time as possible. Keep it full up, air looses heat fast, bottles of beer don't.

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.

 

[Boo2]

Lithium batteries are the answer. You can drain them right down to zero

You should not do that ! If you discharge LiPo batteries completely flat they will "puff" and may catch fire. I don't know how susceptible the Li-Ion cells are to catching fire but you will surely kill one if you run it flat.

I suspect that Woodlouse may be being misled by the use of equipment containing smart battery monitoring / charging circuitry which prevents excessive discharge from occurring but if you ask the toy aeroplane people what happens when you drain a Li battery flat then you will get a very clear answer.

It's hard to find prices, but I remember reading that a Li battery is about 3x the cost. But the battery its self will last about 3x as long (that is the life of the battery, not the discharge time).

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...


Boo2

 

[prv]

Biggest user is the E120 chartplotter at about 7 a/h

Ouch.

Do you really need to run it all the time?

Pete

 

[mjcoon]

... Keep it [fridge] full up, air looses heat fast, bottles of beer don't.

Only makes a difference if you open the fridge, of course. If the fridge stays shut it makes no difference what is inside. No point in opening it if fridge just full of air! Top loading fridge doesn't spill out the cold air when you open it. Putting warm bottles in often will keep the fridge working...

Mike.