This site is now in read-only archive mode. Please move all discussion, and create a new account at the new Victron Community site.
Hi all
I'm looking to buying the BMV-712 battery monitor to go in a 4wd.
The display will be mounted in the back of the car, and the shunt will be mounted under the bonnet next to the battery. My concern is the pcb getting wet under the bonnet. Is it possible to remove the pcb, relocate it to the back of the car near the display, then run a twisted pair of wires from the shunt to the pcb?
Thanks
You might want to consider mounting it in a project box/enclosure, maybe a waterproof one if you are really concerned. Bud is a popular manufacturer.
Just notch the box for wiring and use grommets to keep it well sealed and wiring from chaffing. You want to keep the negative wire short to the shunt, so suggest you mount the box on top of battery.
Here’s a photo of my shunt installed in a small project enclosure which is strapped to the top of my battery in my solar electric catamaran. 
While I've never tested it, I am quite sure that removing the PCB from direct contact with the shunt will cause accuracy issues and should not be done.
I think Solgato's suggestion is a good way to go.
I did consider an enclosure, but unfortunately I don't have much room to work with.
Agree with previous posts.... I got forced into a situation where I had to separate the shunt from the BMS and I'm almost certain the noise I'm getting at the BMS is coming from the voltage noise being picked up over the wire run.
The noise in conjunction with non-linear sampling errors can make it difficult to trust the SOC readings... especially your typical current draws are not significantly larger than the noise.
Consider extending the DC cable run so that an enclosure becomes viable.
Hi Damian.
All a shunt had originally to connect the gauge or display was a twisted pair or shielded cable. This worked without issues for many years, with long runs.
Just don't run the cable directly alongside high current DC devices or AC cables if they are present.
Cheers Darren
To reconcile previous comments with this one - if you're just looking at a point-in-time measurement (i.e. you just want to see how many amps is being pushed into/pulled from battery from the BMV), Darren's right.
On the other hand, if you're wanting to use/rely on the SOC/coloumb counting feature, the cumulative error over time can matter, and you really should use the product as designed (direct mount to shunt). BMV is measuring microvolt signals at the low end.
Thanks all for your help.
