The LVD is almost an emergency use idea. Most people don't want their batteries below about 12.4V. Almost nobody wants them below 12.2V. The battery is 'dead' at about 11.9V. The LVD doesn't disconnect the load until 11.5V, so it doesn't protect the battery as much as it seems. Using the LVD to automatically control a load that often cycles will damage the battery in a short time.
The volt meter would go on the SS-6 battery termminals (will not be too accurate while charging or while loads are on), or have seperate wires down to the battery itself. I would put a momentary-contact normally-open switch in the wire (MOM-N.O.), push the button and the meter works. G-[ Parent ]
