With all the demands on the battery of a serious off road vehicle, auxiliary battery is a sensible accessory. To run that battery you will need a split charge system. The T-Max dual battery system automatically links two batteries for charging, but isolates them when discharging. It has a manual over-ride feature, and a built in safety protection.The system is 12v with 180A load capacity.Kit includes:• Solenoid• Display unit• Wiring and connectors• Full instructions