Battery Ground Question...

[nuttyboater]

In the process of re-wiring my boat, lots of wire splices, someone used red wire for grounds, just an absolute mess that drives me nuts, i'm a bit particular when it comes to electrical stuff.

The question is, i have seen some boats with outboards, aluminum boats, where the battery ground is bonded to the boat and accessories using a connection to the boat for a ground. Just like automotive wiring with the body/chassis being the ground, and i have seen others where they run multiple grounds to everything instead.

What is the usual or common practice for this? I'm thinking of putting in a frame to body ground, or in the case of a boat hull to battery ground, and then using the ground terminals on my fuse block at the console, of course there will be a ground connection from the fuse block to the hull also.

I bought a 6 position, only really need four, marine fuse block to put up behind the console to run a new positive lead to from the battery to feed everything, instead of all the runs of 14awg red that someone else ran all over the place. I also plan on putting a fuse or breaker at the battery which feeds the fuse block.

 

[jevery]

Re: Battery Ground Question...

With corrosion between dissimilar metals where grounds will attach to the hull and the fact that aluminum oxidation is known to degrade electrical connections, seems like you?d eventually be spending a lot of time chasing bad grounds and cleaning connections.

 

[Silvertip]

Re: Battery Ground Question...

There are only three ground points on a boat. 1) Battery negative 2) the ground bus on the fuse panel which connects directly to battery negative. 3) the engine block. There is a fourth ground and that is the engine itself. The through-hull mounting bolts essentially create a "bond" between the hull and the rest of the electrical system but this is not considered a very good electrical connection and should not be relied on for electrical service. As was pointed out, do not use the hull of the boat for ground. Obviously the various instruments and accessories all have ground connections but those are routed back to the ground bus on the fuse/breaker panel.

 

[nuttyboater]

Re: Battery Ground Question...

Ok, thats why i was asking, thanks for pointing it all out. I saw a few boats wired using the hull as ground, and others with an actual ground wire from the battery to the fuse panel.

Probably a matter of experience made those guys do it, as i would have been thinking that the hull should be grounded as if i was working on a automobile.