BMV-712 shunt negative wiring

Question

question

priezti asked 4 days ago

BMV-712 shunt negative wiring

Good day.

I may have gone slightly mad or been misinformed but I'm looking for some clarity to save my sanity:

Using a BMV-712 and shunt, I know that the only thing connected to the battery negative must be the shunt, and any output and loads must be connected to the other side. When a DCDC/Split charge is fitted along with an inverter etc, the negative from the chassis and auxiliary are invariably linked.

Is there any reason that the equipment can't be grounded to the vehicle chassis rather than run all negatives back to the shunt, as it's still monitoring what is passing from the auxiliary negative by the shunt.

Thanks

BMV Battery Monitor Grounding

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Modifications Space

Node Red Space

Answer 1 · 2024-07-23T08:28:25Z

pwfarnell answered · 4 days ago

As long as the shunt is wired correctly with the chassis ground to the load/system side of the shunt then from the viewpoint of the shunt -ve returns can go back through the chassis. However, DC to DC chargers and inverters often run at higher current for prolonged periods and minimising voltage drop is important for these devices, hence it is best practice to wire these directly to a busbar then to the shunt.

why-is-my-shunt-misreading.png (59.7 KiB)

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

question