boat electrics/ water / heating /everything!

[rkane]

Following my earlier message about boat electrics, which got some really useful responses and pointed me in the direction of adverc who will be able to give me specialist help when the time comes on battery management, I have now realised that i need to go right back to basics and try to fathom out the actual systems that we want on the boat before trying to work out battery capacity etc. we've just bought a 32' steel boat and intend to live aboard her and let the house. At present, she's just got very basic systems on her - cold manual water and two betteries charging from an alternator - one for engine and one for lights / nav equipment. into this system we want to add hot water, a cabin heater, a fridge and, possibly, a small dehumidifier such as the new 12v model from Desivent.( At the moment the boat suffers quite badle from condenstation - especially in the forecabin - although we will be improving the insulation over this winter which should help) The problem is, as complete novices in this area of boating, we're completely overwhelmed by the number of options that exist. What we could do with is some advice from people who already have 'complete' systems up and running. we are thinking of investing in a small diesel generator to keep up with electrical requirements as we will have only very infrequent access to shore power and quite like the idea of a dickinson type cabin heater rather than a blown air system. We are also thinking of fittting a calorifier for water heating. Are these good ideas? Thanks ever so much in advance if you can give us any advice. Also, can anyone explain to me ( and I apologise for my ignorance in this field and I am TRYING to find it out for myself from books but am finding it pretty hard going) if you have a charging source (e.g. shorepower or a generator), can you thewn charge the batteries from this source and continue to run your boat system from the batteries? Or do you have to run your system direct from the power source. Sorry if this is a really stupid question!




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[hlb]

No reason why you cant keep charging the batteries and using the power from them. Thats how all boats work. Most these days also have a 240V ring main fitted as well, also a calorifier normaly run off the engine cooling system but also an immersion heater. Think your right to be thinking down to basics as your trying to add what most have all ready got. Of course it all takes up room. Have you got it to spare?? It's not particularly difficult to fit these systems but you will need to know what your doing. I'd start with the generator and give yourself power to do all the other jobs. Might also concider a bigger boat for living on. But maybe better no go There!!

<hr width=100% size=1> <font color=blue> Haydn

 

[poggy]

Hi,

You need to get a fairly powerful charger if you want to run the boat systems and charge the batteries at the same time especially if you plan to add lots of additional equipment. Boat batteries are different from car batteries and you should take care to make sure you use the marine grade batteries which can accept the high charge which boat alternators provide.

Some of the wind generators are pretty good now and have a reasonable output with little noise. This would be a good addition to the diesel generator which is likely to be quite noisy. If you can get a generator with a reasonable output you could use this to heat the water using the 240V element rather than run the main engine and possibly charge the batteries at the same time. I think you can also buy small 2 litre accumulator tanks to balance the pressure of the hot water.

You could buy some solar vents which are good for reducing humidity and don't take any current from the battery. Fridges do take a fair amount of power, even a 40 W average cycling drain would empty a 125Ah battery in less than 36 hours. This would also assume a perfect battery. Obviously if it was a cold environment then the fridge compressor would not be used as much, so battery life would be longer. If you go this route then perhaps a dedicated battery would be a good idea.

As far as living aboard is concerned, I am reading the book "Around the world in Wanderer III" and they spent almost 3 years aboard a 30' boat with a lot of provisions, photo equipment etc on board.

Hope this helps.

Poggy

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[AndyL]

Books

Don't know if you have it, but I'd recommend you get a copy of "Boatowner's Mechanical and Electrical Manual" (2nd edition) by Nigel Calder, published by Intn'l Marine (McGraw Hill). You can order this from www.amazon.com.

It covers everything you have mentioned in great detail including the whys and the how to's with lots of illustrations. There's also some detail about corrosion prevention on steel hulls that you need to know.

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