onlyridepark wrote:flboy wrote:You understood it well and have the right idea. The home run of each negative to a bus bar, then through a shunt to the negative terminal of the battery completes the circuit. On a chassis ground system... put simply, the chassis is just the bus bar.... a very large bus bar where you connect wires closest to the point of use. It just saves a lot of wire. I have a steel frame so not the issues with aluminum and galvanic corrosion.
It also seems like using the chassis ground system then having your shunt between the chassis and battery negative, you would lose some accuracy on the battery monitor. As surely not all loads would pass through it and there would be some losses, like through the tow vehicle itself and any time something was actually earthed. Probably overthinking that part and it really doesn't apply to mine since it will all be home run. Would be nice to only run half the wiring but in reality, I don't have a lot of wire to run anyway.
Thanks again for the help.
You are not thinking about the battery circuit correctly... if the shunt is the only thing connected to the battery negative terminal, and then the shunt is on chassis common (ground is really a bad word here as it means something else in the VAC world and then something different again in the RF world ), anything powered by the Positive of that battery, has to return to that battery. If something is running from another power source... it is not part of that circuit and should not (will not) be measured by that shunt circuit.
Also be careful, no matter whether you home run or use a chassis common, there are functional and reliability risks if not done correctly in either case (gage wire used... individual crimps, connections to bus bars, fuse sizes, continuous chassis vs. bolted up chassis, termination hardware, on and on we go) ... done right... either way... no more or less risks. Either is electrically the same and as reliable if done properly. "Done Properly" is the key word . Do what you are comfortable with for sure. Only you have to live with the results.