Now that you’ve added a dual battery tray and dual batteries to run all the additional accessories, how do you wire those batteries properly to make everything work? The Rugged Ridge Dual Battery Relay Kit, of course. The Rugged Ridge Dual Battery Relay Kit is the perfect companion to the Rugged Dual Battery Tray. This relay kit allows you to connect two batteries to your electrical system to handle the extra strain from adding off road equipment like a winch, an air compressor, fog lights or even that stereo system! Because the last thing you want when you are out on the trail or headed to the beach is a dead battery. This kit includes the solenoid, a three position switch, battery cables, jumper cable, wiring harness and hardware. The three position switch allows you to manage the batteries through the use of the solenoid. Position one is the factory single battery mode. Position two uses the main battery, but charges both batteries. Position three allows both batteries to be used for winches or to crank the vehicle if the main battery is dead.