On the 500amp/50mva shunt there is a temp sensor wire connected to the B1 (red) and B2 (black) position. My system has two battery packs. The second battery pack is not monitored by the BMV 712 guage as it is downstream of the shunt. If I remove the temp sensor wire and install two power leads, one to B1 and the second downstream battery pack to B2 will the BMV 712 include both battery packs in it's readings?
@goodxrvn unfortunately not; the BMV calculation is based on current through the shunt. Any battery downstream of the shunt will not be measured. If both batteries are part of the same bank, you should re-wire both batteries to correctly have only the "battery" side of the shunt connected to their NEGs.
Connecting the BMV as you described would, however, offer you the ability to read voltage only of the downstream battery bank; this function is typically reserved for a start battery, and you would need to reconfigure your display and the shunt's aux input settings to show "start battery" voltage instead of "temperature".
Generally speaking, systems have one battery bank, even if the individual batteries of that bank are separated, which means that if one of your batteries in the bank is not being measured by the shunt, the accuracy of the BMV is obviously significantly compromised. If you do truly have two separate banks, then you can connect the power wires as you described above, to fully measure the capacity of and current in/out of one bank, and the voltage only of the second. If both batteries are part of the same bank, however, but just physically separated, then unfortunately you'll need to completely rewire the shunt connection to achieve accuracy in monitoring.
