I am wiring up a 712 smart into a boat. I’ll try and explain my issue….I have 2 x 120ah house batteries wired in parallel as per photo. I have connected the negative terminal on the left battery to battery only terminal on the shunt as per instruction. Connected power cables to both batteries. Connected negative terminal of second battery (right in photo) to load and charger terminal on shunt. Connected positive cable from solar system mppt 100/30 to positive terminal on left battery and negative to load and charger terminal on the shunt. All good so far! See basic drawing.
My big problem is how to run the negative cable from the load and charger terminal (highlighted blue in sketch) back into boats DC system as the cable running from the negative terminal on the left hand side battery is huge (highlighted yellow in photo). If I don’t connect to it won’t have the full circuit? Hope this makes sense!