Getting 12-volts into the hacked-up XJ harness (or what’s left of it) is important to getting power to every part of the Jeep. The factory ’56 CJ-5 battery box is long gone and not really in an ideal place for our build. Instead we modified a newer CJ battery box from Quadratec (PN 55000.00) to fit our firewall. We also added in a junkyard-fresh support to keep the battery in place. The Optima battery is nearly perfect for what we do with our Jeeps since they don’t leak and are up to the task of running a winch, 12-volt cooler, and other electric widgets.