My project for this weekend was to install a battery monitor in my motorhome. I recently installed a large battery bank (480Ah @ 10hr rate). I hope to install an inverter soon so I figured that it’d be good to have a battery monitor that would count every electron for me.
I decided on the Xantrex LinkPro Battery Monitor. Pretty neat unit. Comes with everything you need to install it except wiring and fuse holders. I used an Ethernet LAN cable with the ends cut off to connect the linkpro to everything. The instructions call for a twisted pair of wires between the shunt and monitor so I figured this was a good thing to use. And the LAN cable meets the minimum wire size of 24awg. I needed six wires total, a normal LAN cable has 8 to it was pretty easy.
I decided to mount the monitor just under the counter where I could easily read it while sitting around the various seats in the coach. To get the cable down under the coach I used a long electricians drill which I picked up a local do-it-yourself store for $9.99. These drills are long enough to get through the two floor decks and insulation and they have a hole in them so you can pull a wire back up through the hole you just made. Removing the fire extinguisher holder from next to the door revealed a small unused compartment. That’s where I drilled down through the various floor levels since this area was clear under the coach too.
The shunt (which measures the amperage going into or out of the batteries) I mounted next to the ground bolt which is near the battery bank. Drilling through the thick ford frame for a couple of bolts to hold the shunt in place was one of the hardest parts of the job.
I also added a red LED (12v LED from radio shack) that the LinkPro will turn on when either the coach or engine batteries get down to a set voltage. Or when my main battery bank is estimated to have 50% capacity left. This way I’ll get a good warning in case I’m not paying attention. Especially if I leave the headlights on when shut down the engine. My goergetown has no headlight warning tone so I’ve left the headlights on after parking several times now.
Everything is settable on the LinkPro; Voltage to alarm at for either battery, settable separately, when the backlight is on and how long it stays on, when to call the battery pack fully charged. Every setting I wanted was there, and even some that I didn’t need. You can also use the alarm relay (that I’m using for an LED) to auto-start you genset if you wanted.
Xantrex LinkPro - Battery Chargers | LinkPRO Battery Monitor | Xantrex
I bought mine from The Digital Oasis (no affiliation) for $245 - XANTREX LINKPRO BATTERY MONITOR