My mistake, you don't need the RJ11 on the end, just a 4 conductor cable run from the battery location to where ever you want the monitor. The wires have screw connectors on the monitor end (the RJ11 is for the controller to monitor connection if you were to use Bogart's controller). I used a length of 8 conductor lan cable that I had around the house for this function, I just use 4 of the conductors. Pretty much any 4 wire (or more) twisted pair will do.
If you are thinking of putting the monitor over the fridge you may need access to that spot. Meaning you may have to pull the fridge so you can thread the cable that ETI will leave tucked in there somewhere, through a hole you drill for the meter. The meter just surface mounts via a couple little screws.
I had them run the cable from the batteries, to the inside of the upper cabinet right at the doorway. Open the cabinet, there was the end of the cable.
Above the fridge may be a better spot but it complicates the install. You know your capabilities.
Here's a link to the install manual on the Trimetric, at the end is a wiring diagram. http://www.bogartengineering.com/wp-...structions.pdf