Car battery failure case analysis

Car battery failure case analysis troublesome phenomenon A general-purpose Buick commercial vehicle, according to the analysis of maintenance workers, the vehicle battery is often cut off, usually after a few days, it is difficult to start in the morning and cannot get on the car; a month ago, it was replaced with a new battery However, after three days have passed, difficulties still arise. After repeated inspections at the repair shop, the cause of the problem is still not found. Common sense to review 1. The composition of the automobile power supply system and the working principle of the power supply system First, let us review the common sense of the composition of the automobile power system and the working principle of the power system. The GM power system consists of a battery and a communication generator. Its working principle includes two operation processes, namely, the operation process of the power system when the starter is not running and the operation process of the power system when the starter is not running. When the initiator is not working, the initiator does not rotate, and there is no voltage and charging current. The positive electrode of the battery is connected through the conductor, and the positive idea is responsible for the generator using the machine wire connection, connected to the generator armature terminal, and completed the grounding through the internal rectifier and the generator casing, because the generator power is rectified by the diode, and the forward voltage of the battery supplies power generation When the motor rectifier diode is reversely cut off, the resistance is infinitely equal to an open circuit. At present, during the operation of the power system, only the power distribution system, the supply voltage, and the battery in the generator are used for power supply load conditions. When the machine is started to run, a voltage appears at the armature terminals. Since the voltage appearing at the generator is higher than the open circuit voltage of the positive and negative electrodes of the battery, the battery starts to be charged. At this time, the battery is equivalent to the load generator, and together with the entire automotive power distribution system to supply the generation voltage, because the current design of the automotive generator output power is relatively large, when the entire automotive power distribution system is under a large load, it can also meet Demand to maintain a sufficient condition of the battery. And choose a battery with a small capacity, only when you use its satisfactory machine to start, or a satisfactory ACC block electrical system to operate the system for a short time. In other words, when the generator is in the power generation state, the load of the battery and the vehicle power distribution system is equal to the load of the generator, and only the generator is in the power supply state. Warm skills, because of the backward processing technology of automobiles and the basic application of low-power generators, it is difficult to meet the requirements of the entire automobile distribution system. Therefore, the power supply of large-capacity batteries is selected to meet the requirements of the entire automobile distribution system. In addition, low-speed starters are used for cars, which require a larger starting current. In order to ensure a stable starting, suitable large-capacity batteries are required to start useful. Now, choosing high-speed electromechanical equipment with reducer can reduce the very large starting current. 2. The whole vehicle power distribution system common to all vehicle distribution systems can be simplified to a load without switch control, and there is a switch to control the load. The load is operated without a switch and consists of a so-called normal fire, that is, a power distribution system with a weak current is used to activate the normal operation of various electrical systems. For example, body network system, central control door lock system, appearance wireless system, etc. The load controlled by the switch is composed of the power distribution system of each electric control system and the normal operation function of the electric system, and is operated by the ignition switch or each electric system. The power distribution system is controlled by the ignition switch or the operation switch. When the ignition switch or the operation switch is in the closed state, it does not form a circuit and is in an open circuit state. The load has no switch control. When the starter is not working, the battery is in the load state as an independent power source. The load with switch control is turned on when the starter is not working, and the battery is used as a separate power supply. When there is a problem between the wires that connect the power supply and the load and form the circuit, it either constitutes an open circuit state, or constitutes an overload state and a short circuit state. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.