Originally Posted by SlowButSteady
Actually, I'm in the process of upgrading some of the wiring on the boat right now. The little plug-in meter is being replaced with a hard-wired one (and an "(ON)-OFF-(ON)" toggle switch, so I don't have to switch the master switch back and forth to test both banks). However, I am going to run heavier gauge wire to all the plugs to avoid voltage drops.
The volt meter should ideally be run directly to each battery with its own wire and should not pull off the "panel". This keeps the monitoring wires free of loads thus no voltage drop other than the mA to power the LCD of the meter which means squat to the wire. Your meter won't have the resolution to even see the load of the volt gauge in terms of volt drop..