What is the function of a car capacitor?
2 Answers
Capacitors in cars primarily protect the battery and onboard electronic devices. Here are the specific aspects: 1. During car ignition: The instantaneous current passing through the motor is very large, which is why the batteries installed in cars are starting batteries rather than ordinary ones. Even so, the impact on the battery is significant. After installation, the capacitor can provide some of the instantaneous current. 2. When the horn sounds: The current is very high when the horn sounds, and the instantaneous high current can easily damage the battery. 3. When flashing headlights: The current is also high when flashing headlights, and the instantaneous high current can easily damage the battery. 4. When turning on the audio: High notes require a very large current, similar to how sudden loud sounds can hurt the eardrum, the instantaneous high current can easily damage the battery. 5. During ignition: It eliminates faults such as CD or DVD rebooting.
With over a decade of car repair experience, I've found that car capacitors primarily serve as 'current reservoirs.' For example, audio enthusiasts upgrading their sound systems must install large capacitors because the instant a subwoofer hits that 'boom,' it consumes massive power. If the battery can't keep up, the lights dim. The capacitor stores 12V electricity in advance and releases it immediately when the amplifier needs it, preventing voltage fluctuations that could damage equipment. In some older cars with aging alternators, headlights may flicker when idling with the AC on—adding a capacitor can help alleviate this. It's crucial to match the capacitor to the vehicle's electrical system; installing it backward can cause it to bulge and crack like a small bomb. Regularly check the capacitor casing for leaks, as that indicates it's time for a replacement.
