What Causes a Car Battery to Keep Making Noise?
3 Answers
The noise emitted by a car battery is caused by oxygen generated at the positive electrode diffusing to the negative electrode, where it combines with hydrogen produced at the negative electrode to form water. Meanwhile, the internal pressure of the battery increases as uncombined gases accumulate until it reaches the pressure required to open the safety valve, releasing the gases and producing the sound. It's important to note that if the battery is fully charged and the noise occurs without any significant load, it is likely due to poor contact between the bolts and wires, resulting in a discharge phenomenon that produces a buzzing sound. If the noise occurs during charging, it is the sound of the electrolyte, which is a normal phenomenon. When facing a situation where the car battery makes a clicking sound after charging, it is recommended to first connect the charging device to start the battery. If the clicking sound persists and the battery fails to start, it is advisable to take it to a professional repair shop to inspect the starter. To prevent this situation, follow these charging guidelines: First, ensure full charging and shallow discharging. Do not wait until the battery is completely drained before charging; charge it whenever possible, and make sure to charge it fully each time. Second, the battery can be used after the indicator light changes, but it is best to continue charging for an additional hour before disconnecting the power, not exceeding 2 hours. Third, if the battery is not used for an extended period, ensure a full charge every 20 days or so. Fourth, if the indicator light does not change after 8 hours of charging, disconnect the power and have the battery inspected to determine whether the issue lies with the battery or the charger. Prompt repairs are necessary to prevent overcharging and swelling of the battery.
Last year, I encountered a buzzing issue with the battery, which turned out to be a faulty relay emitting the humming sound. The battery itself doesn't make noise, but if the nearby relay is aged or loose, it can vibrate continuously and produce noise. Additionally, when the voltage is too low, the charging system will trigger an alarm sound, indicating the battery is nearly drained. Generator failure is another common cause—if it malfunctions, abnormal current can generate similar noises. During my inspection, I found corroded electrodes, which also caused a squeaking sound when the connection was poor. For safety, don't ignore such situations—stop immediately to check fuses and wiring, and visit a repair shop to test the voltage with tools if necessary. Remember to perform regular maintenance; cleaning battery terminals can prevent such troubles.
A continuously beeping car battery is quite dangerous. This happened to my friend's car, with the sound persisting nonstop. It's usually triggered by insufficient voltage or a short circuit activating the alarm. When relays or fuses fail, they may vibrate and produce a buzzing sound; aging batteries with rising temperatures can also create noises due to thermal expansion and contraction. If the alternator malfunctions, unstable charging may accompany flashing dashboard warning lights. It's recommended to immediately turn off the engine and use a multimeter to check the battery voltage. Avoid driving forcibly to prevent potential fires. I suggest inspecting the battery casing and wiring during every car wash to prevent aging-related failures.
