What is the normal value for car battery leakage?
2 Answers
The normal value for car battery leakage is 45 milliamperes. The solutions are: 1. Turn off the ignition switch, all electrical devices, and all doors; 2. Lock the car with the remote to put the vehicle into sleep mode; 3. Loosen the negative terminal screw and replace the leaking circuit. The functions of the battery are: 1. Provide a strong starting current to the starter when starting the engine; 2. Assist the generator in supplying power to electrical devices; 3. Charge the battery when the generator's terminal voltage is higher than that of the battery. The steps for replacing the battery are: 1. Remove the battery's fixing mechanism. Some batteries may have a protective casing that needs to be removed; 2. Disconnect the negative terminal of the battery. Do not disconnect the positive terminal first, as a short circuit may occur if the positive terminal touches the car body, producing sparks; 3. Remove the positive terminal of the battery. The positive terminal may have a protective device, so take care to avoid damage during removal; 4. Replace the old battery, secure the new battery, install the positive terminal, and then the negative terminal.
I previously tested several cars, and the ammeter reading between 20 to 50 milliamps after turning off and locking the car is considered normal. If it exceeds 50 milliamps, the battery is prone to draining. New cars manage the dormant current well, but with more electronic modules, the leakage current can be higher. However, exceeding 80 milliamps definitely indicates a problem. Last month, a friend's car had a leakage current of 120 milliamps, and it turned out to be a short circuit in the dashcam's power cable. It's recommended to use a multimeter to measure for half an hour before taking the reading, and remember to turn off additional electrical devices like the anti-theft system. If the measured value is too high, check the fault source by pulling out the fuses one by one. Aging wiring in older cars is the most common cause of problems.
