Electrical overload at bow area 1

[aircraftengr]

Hi,

I build yachts and in this industry there tends to be lots of additional demands on equipment with reduction in power supply. I'm using limited 8D and 4D AGM batteries for engine, house and generator but I can't figure out how to keep the bow thruster, anchor windlass and down to something below 4/0 wire size. Often my calculations show an overload.

Theoretically the engines should be connected to its own battery, but will it have serious implications if I connect another equipment with a moderately large load to the engine battery as well? The total load does not exceed requirements.

I need advice.

 

[DougMSOE]

You should have separate batteries or at lease be able to separate the starting batteries from the rest of the electrical load on your boat.
Could there be serious implications NOT separating the starting batteries... YES, you may not get the engine(s) started!
The way I have set up several different boats (yachts, a tug, 2 fishing boats 30+ ft, etc,) was to have 2 separate generating (charging) systems, 1 for the starting batteries, the other for the rest of the equipment. But with a tie to the starting batteries to the communications equipment, just in case.

 

[aircraftengr]

Twin engines, actually. Each have their own primary 8D batteries but it looks like I will have to siphon off some for the other equipment on board.

I do have a sizeable generator and efficient battery charger though and it will most probably keep the batteries charged and in good shape.

Then again, I might look into it deeper - I haven't launched the boat yet.

 

[AngelAlvarez]

About what loads and distances we are talking about? Distance between housing batteries and the bow? Distance between starting batteries and the bow? Load from bowth. and windlass?. Do you need to use both starting batteries? Maybe with one you can make it. Do you have a parallel switch?
Best Regards
Angel

 

[aircraftengr]

Batteries are in the engine room. Engine room is aft/middle of the boat. We're talking about distances of 40ft one way when you consider the wiring. Loads about 680A.

I've been advised against parallel switching. I'm wondering if it's possible to stagger or sequence the starting, so it doesn't overload at once. What kind of circuitry will that require?

 

[Cyclefrog]

Since anchor windlass and bow thruster loads are intermittant, consider locating one or more additional batteries up forward, with diode protection on the charge circuit. Who supplies your thrusters and windlasses? Their tech support people should be able to help with circuit design. The Sidepower section of

http://www.imtra.com

has some helpful materials. Or take a look at ultracapacitors (see

http://www.maxwell.com).

 

[aircraftengr]

Relocating batteries is easier said than done. There needs to be sufficient ventilation, especially for wet cells which have sulphuric acid as the electrolyte. I'd have to install another moisture eliminator/demister/blower there to avoid any untoward incidents.

Not to mention I have my fresh water tanks at the forward section. It is very damp.

Actually, I deal directly with Sleipner but the Norwegians don't seem to be able to help with our own internal circuitry. They are good with their products though.

All my boats have ELCB and GFCI.

 

[fury1965]

Would you like a diagram? What size alternator do you have on your engine? How big is your windlass motor?

 

[fielder]

I ran across what I thought to be a very clever instalation for a anchor winch this last summer on a new Benteau sailboat.
The switching for the winch controls were wired into a solonid ~ triggered fron engine oil pressure. which in effect would not allow the winch to be opperated unless the engine was running. Hence avoiding the unforunate situation of running the batterys low and all the other problems arrising from this condition.