Hello. I recently purchased a BMV 712, but due to how my wiring is done it's a bit trickier to install than I expected, at least for a relative noob like myself. My setup is the following, illustrated with my super paint skills:
A 3x130AH AGM house bank connected in parallel via a bus bar (not the usual battery to battery parallel setup), and this same bus bar also has connections to the bigger loads like the bow thruster and windlass. Each battery is connected directly to the bus bar using 70mm2 90° cables, and the thruster wiring uses 2x50mm2 protected by 300A fuses.
Now, in order for me to keep the same current capacity it seems to me I would need to connect the three battery negatives all to the battery side of the shunt, then use 3x70mm2 cables to connect the shunt to the bus bar. That does seem to be overkill as my total ampacity would be ~900A. Can I get away with 2x70mm2 instead?
I'm also wondering if I need to get a bigger shunt? The thruster is a MaxPower compact rectract rated at 4790w, so it would only draw a max of 400A, and is only used with the engine running, so it seems to me the 500A rating of the shunt is good enough.
