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Dan McMartin · 01-13-2018, 11:13 AM

Looking at installing a battery monitor, either the Trimetric or Victron. I generally understand how to install except for one thing. Is the chassis ground capturing all the current used by stuff that grounds to the chassis? I can't find anywhere that explicitly says that.

Most advice is to connect ALL negative leads to the shunt. I assume the chassis ground lead to the monitor will deliver that information otherwise everyone would be rewiring their rigs to bring ground leads to the shunt. Like I said, dumb question but I want to know for sure.

BrentB · 01-13-2018, 11:26 AM

I was wondering that myself when I got mine. I can tell you that my power tongue jack is grounded directly to the frame through the mounting bolts, and it's power draw does show up on the monitor.

Dan McMartin · 01-13-2018, 11:28 AM

I figured that was the case but as I mentioned, I haven't seen anything that specifically states as much.

twinboat · 01-13-2018, 11:30 AM

Yes, anything running from the house battery, using the chassis ground, will return thru the chassis ground cable to the negative of the house battery.

One side of the shunt should have ONLY one cable. That goes to the negative battery post.

cruzbill · 01-13-2018, 11:30 AM

Find where the negative batt cable is attatched to your battery bank. Put the Shunt in series with that battery cable. As for your tongue jack, its return path to negative is still thru the negative battery cable. Same story.

F76Marion · 01-13-2018, 11:55 AM

Dan,
It is no small surprise that you are confused.
For any of the good real battery monitors to be effective, it has to see all the current going into or out of the house bank. To do this, you have to isolate just the house battery ground. That means the shunt has to be between the actual battery lug(s) and everything else. How it gets there is not really any issue as long as it is there and there is nothing else connected to the battery negative.

If that isn't clear, I can try again.

Before the depression, we installed a lot of these in owners boats. Boats are a little clearer because there is no chassis ground in a fiberglass boat.

Frank

Dan McMartin · 01-13-2018, 12:40 PM

I think I understand it. All grounds go to one side of the shunt and then from the other side, a single ground cable to the battery. I just wanted to verify that grounding to the chassis would return through the chassis ground and I didn't have to directly connect those loads to the shunt.

Thanks!