Weak current power supply system of electric vehicle

The invention discloses a weak current power supply system of an electric vehicle. An electric vehicle is provided with a high-voltage battery pack composed of single batteries. The high-voltage battery pack is provided with a high-voltage total positive electrode and a high-voltage total negative electrode, and the high-voltage total positive electrode and the high-voltage total negative electrode are respectively connected with the input ends of a DCDC controller. The output ends of the DCDC controller are a low-voltage total positive electrode and a low-voltage total negative electrode, andthe low-voltage total negative electrode and the low-voltage total positive electrode are connected with power input ends of vehicle-mounted electrical components. The system of the invention has theadvantages that, the cost of a vehicle is reduced, the cost of battery units and peripheral auxiliary wiring harnesses is saved, vehicle batteries are eliminated, the weight of a vehicle is reduced,the endurance of a vehicle