The inspection method of automobile leakage and the normal range of leakage

The car battery has self-discharge characteristics, even in the absence of any electrical equipment, there will be power loss. If the car has been parked for a few days, it is difficult to start or the electrical appliances are not working properly, and the engine failure is eliminated, it may be caused by the battery. If there is no electricity after a few days, it means that the car is leaking.

Causes of car leakage

1. Leakage and loss of battery caused by the electrical switch not turned off when parking;

2. The battery plate is short-circuited or oxidized and falls off, resulting in self-discharge and power loss;

3. Because of automotive electrical appliances, wiring harnesses, sensors, controllers, actuators and other electronicsYuanLeakage caused by grounding of devices and circuits.

Inspection method for car leakage

1. Observe the color of the observation hole of the battery, and check whether the appearance of the battery is intact and there is no leakage.

2. Use a multimeter to measure whether the battery voltage and power generation are normal, the normal voltage is above 12V, and it is not less than 10V after continuous discharge for 10s;

3. Remove the negative connection of the battery, set the multimeter to the current position, connect the red test lead to the negative connection of the battery, and connect the black test lead to the negative terminal, and observe the value of the ammeter. Compare the measured current value with the maintenance data to see if it is within the normal range (different models have different standard values). If the measured current value is too large, it means that the car has a leakage fault.

4. Turn off all electrical equipment on the car, the door and trunk are locked, disconnect the negative electrode on the battery and wait for 20 minutes, then connect one end of the test light to the battery negative wire and one end to the battery negative pole; if the light is on, it means Electrical equipment and lines are still leaking electricity. At this time, check the relay andfuse.

When the car is turned off, the battery must maintain a small amount of external discharge current to ensure the normal operation of anti-theft devices such as anti-theft devices. This external discharge current is called "dark current." The dark current leakage of the battery is a major factor that causes the battery to lose power. The more advanced the car, the dark current will increase with the increase of automobile electrical equipment and the increase of the battery capacity. When the car is locked, the current will be relatively large. After waiting for about 30 seconds, the current will drop to less than 50 mA, which belongs to the normal current range. If it exceeds, it means that the car is leaking and needs to be repaired or replaced in time.