Boat Generators

[MtB]

On 05/08/2017 at 16:50, Jacobyte said:

 

Looking at alternatives if not generator/charger then maybe Solar panels, just want some help/guidance on this issue, thought the users of this forum would know all about this subject owning narrow boats.

 

 

The thing about solar panels is the output from them varies MASSIVELY according to the weather and the time of year. In summer my single cheapo 100w panel keeps the fridge and a few lights running perfectly easily but on my other boat, I have 560W of solar and that fades out to zero come November. 

So if you want something to tide you over until you get the engine fixed, I'd say a 100w panel or two and a cheapo PWM contoller Like I have on the smaller boat will probably do you fine.  BUT, it all depends on your power consumption and you have posted no information at all about what you have in the boat AFAICS, or how you'll be using it.

This kit looks a good deal from a well regarded retailer:

http://www.bimblesolar.com/offgrid/12v/175w-pwm-kit

But as I said, it could turn out to be more than you need or grossly undersized, but my guess is it will be just right.

P.S. its a 12v kit but unless you can explain why you think you have 24v on such a small boat, I remain to be convinced. 24v is virually unheard of on small GRP cruisers, and utterly pointless.

[rusty69]

9 minutes ago, Mike the Boilerman said:

 

This kit looks a good deal from a well regarded retailer:

http://www.bimblesolar.com/offgrid/12v/175w-pwm-kit

But as I said, it could turn out to be more than you need or grossly undersized, but my guess is it will be just right.

P.S. its a 12v kit but unless you can explain why you think you have 24v on such a small boat, I remain to be convinced. 24v is virually unheard of on small GRP cruisers, and utterly pointless.

You can't really go wrong at that price, assuming room to mount it and a 12v system. Will keep the batteries from self discharge over the unused Winter months too. 

[Jacobyte]

1 hour ago, Mike the Boilerman said:

 

The thing about solar panels is the output from them varies MASSIVELY according to the weather and the time of year. In summer my single cheapo 100w panel keeps the fridge and a few lights running perfectly easily but on my other boat, I have 560W of solar and that fades out to zero come November. 

So if you want something to tide you over until you get the engine fixed, I'd say a 100w panel or two and a cheapo PWM contoller Like I have on the smaller boat will probably do you fine.  BUT, it all depends on your power consumption and you have posted no information at all about what you have in the boat AFAICS, or how you'll be using it.

This kit looks a good deal from a well regarded retailer:

http://www.bimblesolar.com/offgrid/12v/175w-pwm-kit

But as I said, it could turn out to be more than you need or grossly undersized, but my guess is it will be just right.

P.S. its a 12v kit but unless you can explain why you think you have 24v on such a small boat, I remain to be convinced. 24v is virually unheard of on small GRP cruisers, and utterly pointless.

2 x 180 Ah 12v batteries connected in parallel would be the correct answer.

 

[rusty69]

1 minute ago, Jacobyte said:

2 x 180 Ah 12v batteries connected in parallel would be the correct answer.

 

So a 12 Volt system then. And a fair size too. 

[Jacobyte]

2 hours ago, Tony Brooks said:

That is a small boat and I suspect the  size and shape of the roof will severely limit the amount of solar you can fit. I think that you should get enough on to keep the batteries charged and recharge them when you are away from the boat for a few days. I very much doubt that it will be enough to provide your domestic needs.

I note that you have had a lot of help before you thought to disclose what sort of boat you have and how you use it.

Are you sure its 24 volt, that would be an unusual Seamaster 23 if it is. More likely 2 x 100 Ah ish 12v batteries connected in parallel to give 12V at twice the capacity.

I expect this forum knows more about the subject that almost anyone else BUT if you do not provide the information we can only guess.

All being well the engine WILL charge the batteries as long as you run it for long enough but long enough could be in excess of 8 hours a day, more if you do not run the engine every day.

What are the results of your power audit? What is the output of the alternator? What is the label capacity of the batteries? All need to be answered if we are to give sensible advice.

I and several others use a voltmeter to know when it is vital to start charging but in reality for optimum battery life it should be every day, and an ammeter to show when the batteries are more or less fully charged. Using the voltmeter and getting reliable results takes knowledge, practice and experience. There is a sort of fuel gauge for batteries known as a Smartguage and that is about the best you can do if you are inexperienced. Other type of "fuel gauges" for batteries that count amp hours are almost certainly going to cause the inexperienced to ruin batteries.

My advice is to get the engine running properly and use that for charging initially. Anyway I think most Seamasters of that age use a calorifier for hot water and that needs the engine running to work.

Ignoring the real safety concerns I think the  generator you link to plus a suitably sized battery charge (suitable for generator) will do for now BUT there is still a question   about the wave form and if electronic charger will run on it.

2 x 180 Ah 12v batteries connected in parallel and it's a wide beam river cruiser at 9"2' so has a decent size cabin roof, as for not disclosing what sort of boat I have before getting help, I originally asked about a small generator to use if it was needed in an emergency if my leisure batteries needed charging and for some reason I had broken down, so did not think that would come into it.

8 minutes ago, rusty69 said:

So a 12 Volt system then. And a fair size too. 

Yes & Yes

[rusty69]

8 minutes ago, Jacobyte said:

2 x 180 Ah 12v batteries connected in parallel and it's a wide beam river cruiser at 9"2' so has a decent size cabin roof, as for not disclosing what sort of boat I have before getting help, I originally asked about a small generator to use if it was needed in an emergency if my leisure batteries needed charging and for some reason I had broken down, so did not think that would come into it.

Yes & Yes

I would definitely invest in some solar. Something like mtb suggested or bigger with an mppt controller if funds and space  allow. 

Edited August 5, 2017 by rusty69

[Tony Brooks]

12 hours ago, Jacobyte said:

2 x 180 Ah 12v batteries connected in parallel and it's a wide beam river cruiser at 9"2' so has a decent size cabin roof, as for not disclosing what sort of boat I have before getting help, I originally asked about a small generator to use if it was needed in an emergency if my leisure batteries needed charging and for some reason I had broken down, so did not think that would come into it.

You had the answer within the first three or four posts and then you asked another question where far more information is needed. From memory your gunwales/catwalks beside the cabin are over 8" wide, you have wooden rubbing strakes topped with steel or rubber at the join between hull and top moulding say  another 2" per side. Then the tumble home of the cabin side, say 2 " per side plus any curvature where the cabin top meets the side but I seem to recall the Seamaster 25 had very little, it was almost a right angle. That lot adds up to about 2 ft so that leaves a cabin roof width of  7ft 2". Then there is the fact that the roof is not a rectangle so the effective width is rather less than that. Given that solar panels can only be relied upon to give around 1/3 of their rated output or a little more in summer, and less on dull cloudy days, I still believe you will not get sufficient solar on the roof to do what you want. As soon as you asked for alternatives anyone who wanted to give a well thought out answer needed far more information from you. Now that is not your fault as you probably have no idea all that is involved.

I think I have seen some Seamaster 23s with a solid fixed roof over the cockpit. If yours has this then solar becomes far more likely to be sufficient.

As a guide. I have 160W of solar moued horizontally on the roof. The most I have had out of it over one of the long hot June days was 35 Ah. That will not even cover the demand of the fridge, let alone all the other electrical equipment. This is why, if you want advice that is more likely to be successful we need to know your power audit figures and how you use your boat.

[Jacobyte]

6 hours ago, Tony Brooks said:

You had the answer within the first three or four posts and then you asked another question where far more information is needed. From memory your gunwales/catwalks beside the cabin are over 8" wide, you have wooden rubbing strakes topped with steel or rubber at the join between hull and top moulding say  another 2" per side. Then the tumble home of the cabin side, say 2 " per side plus any curvature where the cabin top meets the side but I seem to recall the Seamaster 25 had very little, it was almost a right angle. That lot adds up to about 2 ft so that leaves a cabin roof width of  7ft 2". Then there is the fact that the roof is not a rectangle so the effective width is rather less than that. Given that solar panels can only be relied upon to give around 1/3 of their rated output or a little more in summer, and less on dull cloudy days, I still believe you will not get sufficient solar on the roof to do what you want. As soon as you asked for alternatives anyone who wanted to give a well thought out answer needed far more information from you. Now that is not your fault as you probably have no idea all that is involved.

I think I have seen some Seamaster 23s with a solid fixed roof over the cockpit. If yours has this then solar becomes far more likely to be sufficient.

As a guide. I have 160W of solar moued horizontally on the roof. The most I have had out of it over one of the long hot June days was 35 Ah. That will not even cover the demand of the fridge, let alone all the other electrical equipment. This is why, if you want advice that is more likely to be successful we need to know your power audit figures and how you use your boat.

Yes my Seamaster 23 has a fixed roof over the cockpit, the fridge/small tv use most power, have fixed Led lighting that use less power, but fridge uses most power. in one of your previous posts you said cruising for 8 hours a day should provide sufficient charge but unfortunately that would not be possible, as my younger sister who travels with me has a severely bad back problem and so can only travel at best 4 hours before pain becomes too much for her to continue. As for the power audit figures, I would not at this moment in time be able to give an accurate reading as this is our first long distance trip on the boat. You are also correct in that I asked too different questions but both were aimed towards charging my leisure batteries.

I have only owned this boat for a year, so still need some time to get to know it's ins and outs properly, thanks to everyone one has given advice on this subject and I wish everyone happy boating, I will use all the advice given here to decide my next course of action, thank you Mike.

[Tony Brooks]

If the fridge is a compressor one then plan on 50Ah per day. If its a 3 way fridge running on 12V then plan on about 180 Ah a day and solid tomatoes & milk. Add 12  Ah for 4 to 6 hours of TV (assuming a flat screen) plus say 10 Ah for lights and pump. That comes out at 72 Ah per day. On my solar figures in long bright days in June you will need over 300 Watts of solar and more during dull days and as you move further away from June either way. I think it is possible to mount that amount if you use your cockpit and cabin roof but it will be far more expensive that that generator when you add in the solar controller (MPPT for best output).

However that discounts any engine running. Until identified I would expect your alternator to be something like a modest Lucas ACR of 35 to 45 amps out put. It may have been changed for an A127 @ 50 amps (all informed guesses).  Lets assume the higher figure. That gives a very rough average out put over 3 to 4 hours of about 25 amps so over 4 hours that equates to about 100 Ah BUT 10% to 40% of that will be lost in the charging process depending upon all sorts of factors. Lets say 20%. That means for 4 hours cruising you put back in about 80 Ah but unless you run for far longer that 4 hours it will only be about 80% fully charged. So 4 hours of engine charging will cover your loads but not fully charge the batteries. During the summer maybe 200 watts of solar will complete the battery charging each day as long as you engine charge earlier in the day.

That amount of solar will easily recharge the batteries when you leave the boat and go home for some days. It will also keep them very well charged over the winter.

Hopefully this will show why you were advised that engine charging was, perhaps, the best option.

Assuming my rough power audit is about right lets look at charging via the generator you linked to and that it will drive a  15 amp charger. Although the charger is likely to be a bit better at getting electricity into the battery than the alternator the way batteries accept charge means that its  safest to make similar assumptions to those for the alternator. Over a 4 hour period  its likely to put back in an average of 4 x 7.5 amps = less than 30 Ah once you take charging efficiency into account. That is less than half the domestic demand so you will need to run it for far, far longer, maybe 8 to 12 hours for 100% charge. Even if the generator will drive a 20 amp charger the time to 80% charged will be shorter but it will not be much shorter if you want to go to 100%.

I hope that you can see that for 100%  charge you need a lot of solar, even in the  summer, or  a combination of engine/generator charging early in the day plus more modest solar.

Charging to 80% for a week or so when you are on the boat is unlikely to massively reduce battery life AS LONG AS you charge to 100% about once a week.

Unfortunately you can not alter the electro-chemical processes involved in charging to suit your demands. If you want decent battery life you have to modify your demands to suite the way batteries charge and the equipment you have.

Edited August 6, 2017 by Tony Brooks

[Gareth E]

Personally I much prefer the noise of a (quietish) 4 stroke generator to the horrible low pitched drone of a modern diesel engine. I'd happily be in line with boaters using generators for a few hours each evening but if they are running their engines, I'm off. Don't let the generator haters put you off, this matter is subjective.

Solar alone is unlikely to provide all of your needs all of the time. Things can break down and for these reasons, I'd always have a generator.

I have a Kipor Sinemaster IG770. It's quieter (67db max) than the one you linked and just over half its weight. It has a device that limits the rpm to that needed to produce the current the batteries can take. This means that as batteries approach full charge, this can take a few hours, it uses very little petrol. It average 2 1/2 hours on 1 litre but I rarely let my batteries get heavily discharged. I bought mine nearly new for 170 quid, I think they are around 300 new. The only downside is that parts may be difficult to source, but I'm not there yet. 

Hope that helps.