Xantrex 20+ charger install issue

[TigeDuner]

Xantrex instructions require a ground bar for the attachement of the negative post on the batteries and the negative feed from the charger. Since this is a marine application and all ground cables end up tied together on the batteries, is it really necessary for the ground bar or can the ground on the charger just be tied to the nearest battery? I had also thought about putting a "ground bolt" through the platform the battery sits on and bolting all the negative cables to that and the engine ground. Thoughts???

[spharis]

If you have alot of grounds, like in cuddy cabins and stuff, then it is easier to have a bus bar for grounds. I have 1 neg cable going to my battery compartment, so straight to it is a no brainer for me. I suppose if you had many large terminals, it would be cleaner, especially for removing the battery if you had a grounding lug.

[Razzman]

I'm with SP on this one. I just installed three small bus bars last week under the dash for all the accessory connections (+ switched, + unswitched and ground ) for things like the depth gauge, stereo remote, Orion gain knob, light switches, etc and it really makes life easier connecting everything up! I have one positive and one negative coming from the dist blocks to them.

[TigeDuner]

The reason for my question was that the negative terminal on the starting battery that is connected to the engine ground is stacked with cables and Xantrex says to connect to a ground bar. Electrically speaking for charging batteries, is a seperate "bar" really needed? I get the feeling Xantrex is worried about "backfeeding" of the charge to the batteries through the negative cables, but even with a ground bar, both battery banks eventially end up tied together.

[spharis]

You will get groundloop ("backfeeding") worse through a bus than connecting straight to the battery.

[TigeDuner]

Thanks spharis. I think I will install a remote negative terminal near the battery and loop over to the battery. This will allow all the cables to be stacked on the remote terminal and only one or two to be on the battery post in the battery box.

[spharis]

That's what I would do if I had more than 3 or so.

[Domsz06]

where are you getting these ground bars? I need a few.

[spharis]

You can buy some threaded rod, and just have mount it in the compartment assuming you have it through fiberglass.

[Razzman]

I made my own. A piece of poly board (cheap cutting boards from Big Lots!), ran a bolt up through the bottom (countersunk in board on bottom) with dual nuts on the top, two mount holes and bolt it down anywhere you need one.

[TigeDuner]

where are you getting these ground bars? I need a few.

Dom, I suggest using stainless bolts. Mine is in the battery compartment and could get spashed from water in the well. Probably not, but just in case.

[Razzman]

I used brass bolts, nuts and screws on mine as i had them laying around in the bin. I personally wasn't worried about water up under the dash, if it gets wet there it's probably sinking anyway!

[spharis]

Insurance at that point IMO. Go ahead and help it sink.

[Razzman]

Insurance at that point IMO. Go ahead and help it sink.

Exactly!

[Domsz06]

ok, i'll just make my own thanks guys