Pekeri said...
The excellent responses I have received are way beyond what I expected.

Brilliant, really made my day to get so many positive contributions to my little project.

Will post completed project.

Guitz, I look forward to catching up.

Totally agree thanks everyone for your input

SandS said..

I have heard people say that being close to Aluminum boats in Marina.s can be a bit dodgy. Any one have knowledge on that situation ?

I have seen some Alu boats hanging anodes of some description over the side ,dangling in the water . Not sure on the reasoning ,is it just to get the anode well away from the alu hull ?

It's dodgy for the aluminium boat. Stray 12 volts will effect aluminium vessels and the fastenings on timber vessels. In a marina you have all those vessels with solar panels making power in the daylight, lets hope they are carefully wired.

My 2 cents worth ...... I worry about safety of 240VAC mains on boats, near saltwater ....

If the marina 240V power outlets are up to standard they should have a 240V:240V isolation transformer on each, and an earth leakage cutout on each which improves safety but unless you actually see it and know its tested there's an unknown risk there. ie. Electricians in industry working on a power system personally switch the main switch off and tag it rather than believe someone who said it was off!

My understanding of the galvanic problem is it happens when a current flows through dissimilar metals or ionic conductors touching each other. Salt water/ wet timer / anything that conducts. Shore power is carried into the load (boat) through the active wire and back out via the neutral. Its the passing through that allows work to be done (Charging batteries etc). That power in the active wire also wants to go to ground but we don't want to let it. It should only go back out by the neutral wire. If you touch active and are touching the ground it will go through you and be very unpleasant. If some tiny or otherwise amount of it goes to ground via a boat and its fittings or hull to the sea then all the dissimilar touching parts of the path will have some kind of destructive reaction happen. AC is less prone to do that because its "polarity" reverses at 50 times per second (50Hz) than DC so it "fixes" a bit of its electrolysis 50 times a second too.

Finally to end my waffle!! I suggest take care of safety first.

In lots of places you can buy a 240VAC to 240VAC isolation transformer. Consider getting one and plug you boat circuits into it and then it into the shore power. Then the 240V essentially comes out of your transformer and back into it with nothing to do with the mains any more. The sea and other grounds are irrelevant. Your boat is then "galvanically isolated" from the marina. I think there cant be problems caused by leakage and electrolysis, and safety is much better.

admire you approach I wish to be like that.....just one thing missing there
....She'll be right mate....

Please let us known what professionals saying...thanks..

thanks for sharing.

It is always interesting to see people sort through the many available options and come up with a solution that meets their particular needs. For me, this is one of the great joys of owning and maintaining a boat.

Before this topic is buried
Please explain your current leakage?
Typically we talking implement RCD
but you didn't apply safety switch did you.
One more ..why you killing your batteries
have them permanently connected parallel!
Electrican didn't tell you they discharging each other.