question

seahawk avatar image
seahawk asked

BMV 712 Wiring

I have a further question. In my setup, I presently have a large 1-ought cable at the battery negative going to ships ground. Also on the neg terminal of the battery I have a cable connected to the other house battery putting the two of them in parallel. Theres also a third negative, smaller gauge wire which I believe goes to the battery charger. So to wire the BMV712 correctly .....I'll disconnect all the existing negative cables from the battery. I'll connect the 1-0 cable that goes to ships ground to the "LOAD CHARGER' side of the shunt. I'll connect another 1-0 jumper....one end from the "BATTERY' side of the shunt and the other end to the neg battery terminal. Is this correct so far. If it is then this is where I get confused. Now, where do I connect that third negative cable that I think connects to the charger. And,....from this point forward, where would I connect any negative cables for other equipment. I know it cant go to the "BATTERY" side of the shunt,.....so would it go to the other end of the shunt,???....or to the battery negative terminal directly. Thanks again for any help. I know theres something obvious that I seem to be missing here. This isn't really difficult but I seem to be making it so.......... :-)

BMV Battery Monitor
2 |3000

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

1 Answer
randy-putnam avatar image
randy-putnam answered ·

I added a bus bar to my boat’s set up and ran all the positive and negative loads off the batteries (2 100AH Battle Born LFPs in parallel) I then connected the bus to the batteries with one cable from the pos side of the battery and one cable from the neg side of the battery. I then connected the “battery” side of the smart shunt to the negative side of the “rear” battery. Worked fine. Here’s a schematic and a picture of what I did:

cc381902-d8f3-40e7-a426-721a45d919fa.jpegff5340d2-1903-4765-866b-afe570ff729a.jpeg

283a02c6-56aa-4f66-8859-9e2fa73bb1f4.jpeg

I liked this particular bus because it has both pos and neg terminals on one unit and fits in the confined space where I installed the house bank. BTW the boat’s a 1977 Trojan F26 and I used to have 2 FLA deep cycle batteries in that compartment with a tangle of pos and neg wires running directly off the battery terminals. This new set up is still a bit of a mess but it’s working fine. Please not that all pos cable connections are fused. I use MRBF fuses wherever I can.

Hope that helps you out.


1 comment
2 |3000

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

seahawk avatar image seahawk commented ·
Thanks Randy....thats a really good set of pics, and it helps alot. Appreciate that.
0 Likes 0 ·