Fault diagnosis of pre-charge relay circuit detection fault code in BYD Qin electric vehicle battery management system

Because the pre-charge voltage did not reach more than 2/3 of the total battery voltage, the pre-charge failed and the pre-charge loop was disconnected. According to the relevant public information, the vehicle charger found the signal through CAN and sent it to the battery manager. With its consent, the two relays are driven to mesh, and the 500V voltage of the battery is sent to the vehicle charger, which really enters the charging stage of the power battery.