Second battery in tow vehicle for boondocking
This summer I'm planning some trips to campsites which, while developed, lack electricity. We will remain camped and take the tow vehicle out for side trips most days.
To make this work, I'm planning on adding a second battery to my tow vehicle. Most full size trucks that do not utilize an engine technology that requires two starting batteries have parts available to mount a second battery.
I'm doing this to my pickup as part of my Avion C-11 project and to my Suburban for towing the Airstream.
For my 1997 Chevrolet pickup, there's a battery tray available that mounts on the left side, over the washer fluid reservoir. Mine had that in place when I got it. It holds a Group 24 deep cycle battery but height is a problem with the hood hitting the positive terminal. I'm either going to modify the hood or put together a reduced-height terminal bus arrangement for the positive side. The negative terminal has good clearance.
For my 2004 Suburban, there's also a tray available. It mounts on the passenger side, close to the firewall, in place of the corner support between the fender and firewall. I just got the parts today and will be trial-fitting a Group 24 in there as the vertical clearance appears to be very tight and may not work.
If I can't make it fit I'll have to use an ordinary starting battery instead and put up with the shorter lifespan.
Once the batteries are physically in place, I'll disconnect the charge line from the fuse block and (with proper overcurrent protection) connect it to the deep cycle battery. I'll also connect the alternator to the battery, through an isolation relay. The result should be that I can operate the trailer electrical components off the auxiliary battery in the two vehicle by connecting the umbilical and placing the store/use switch in "store." When we leave the campsite we can place the store/use switch back in "use" before disconnecting the umbilical, and then the auxiliary battery will charge while we drive.
Photos to come.