This is a complete pre-wired X3 Max Dual Battery Kit. It includes a 6 ga. Power and 6 ga. Ground cables from each battery and integrated charging circuits that will keep the batteries charged when the vehicle is running but separated when there is no charging voltage present. The Accessory circuit from your Accessory Battery is fused with a 100 amp MIDI fuse holder at the Battery to protect your vehicle. This dual battery kit includes everything you need to properly add a secondary battery to your X3 to power to your lights, radios and any accessories. By isolating all your lights and accessories from your starting battery you can avoid being stranded due to a dead or drained battery.