Originally Posted by ianhef
Just for those new to this thread,
1) The boat does not have a 240V system.
2) The internal wiring
is only for 12V.
3) There are no sockets/plugs anywhere on the boat to plug into.
4) I'm just looking for advice on the best way to keep my batteries topped up, run the engine every 2nd day or is it possible to invest in some kind of marine specific charger that will top them up? (without doing any damage to the boat or any of my neighbours)
Any advice much appreciated.
It is all a question of grounding. You should not use AC power on board, and God forbid, on board a steel
boat, without a ground in place. Period. It is a question of life and death for anyone on board.
A wacky ground -- say, the third pin in an extension cord -- might protect people, but will destroy property. More below. (And read the very good discussion in Nigel Calder's book about the tension between protecting people and protecting property, in designing on board AC system.)
A proper, as opposed to a wacky ground requires a proper shore power connection with the ground bonded to your hull
, engine, and other major metal lumps on board, not just brought on board through the third conductor of an extension cord. Without a proper shore power connection (and proper wiring inside your boat), which leads away stray currents safely, those stray currents can leak through the water
and eat up other boats appendages, zincs first we hope, but soon propellors and so forth.
It happened to my expensive Brunton prop, and a dozen other props in our marina (due to some f*ckwad using an extension cord-powered automotive battery charger over the winter in the marina), so that is why I am not quite indifferent to the question of shoddy AC installations in marinas
. One killed propellor costs more than the whole AC system on most boats; and boats can sink
when the electrolytic corrosion
in a hot marina finishes with the props and starts in on bronze through-hulls.
A wacky AC installation
in a marina, and for God's sake on a steel
boat, is an utter menace. You will lucky if the result would be only missing extension cords. I've heard about sea cocks failing at night without explanation . . .
So you have two alternatives to running your engine to keep batteries up, and really only two:
1. Put in a proper shore power installation
with proper grounding and bonding, properly tested by a good electrician; or
2. Use solar
to trickle charge your batteries.
Option 1 will not be cheap, especially on a steel
boat, but you do get the benefit of AC power for other uses.
P.S. Not using AC on board without a proper ground includes using a kettle from a socket mounted on a board. If you prefer being alive to being dead, do not do it
. Do not bring AC power near your steel
boat -- and that includes double-insulated power tools (sorry to disagree with one of the other posters here), without a proper shore power installation.