Here’s an analogy that may help you understand battery monitor shunt wiring.
You have a train station. / You have a battery bank.
You have a train counter that can only count trains going on one track. / You have a shunt.
You want to count all the trains that come into the station. / You want to measure net current on the battery bank.
In order to do that you will want to make all your tracks entering the station converge before they get to the train counter. / All your negative cables must converge before they get to the shunt.
If you have tracks entering the station between the station and the train counter, trains taking those tracks won’t get counted. / If you bypass your shunt with a negative wire going to your battery bank you won’t get an accurate reading.
If you route the exit of your train station through the station your trains will just drive in circles and your train station will be overwhelmed. / No positive leads from the battery should connect to the main posts of your shunt or you will have a short circuit that might result in a fire and a ruined battery. (Side note, if you have a Victron BMV-712, you will need to power it either with a temperature sensor connected to a battery positive terminal to the shunt’s PCB, or a red cable going to the shunt’s PCB.)
If you need assistance with the wiring of your shunt, send us a picture that shows your battery bank, all the wires to going to battery terminals, and the shunt. We will verify that the shunt is not being bypassed or used to short-circuit the battery bank.