What causes the sound of water boiling when charging the battery?
3 Answers
The reasons for the sound of water boiling when charging the battery are as follows. Fan noise: The battery charger has a fan for heat dissipation. If the fan is dusty or the fan roller has insufficient oil, it will produce loud noise, which is the sound you hear. In this case, adding lubricating oil to the fan roller can solve the problem. Magnetic core noise: The high-frequency magnetic core inside the charger is loose. It can be tightened with a piece of paper and then sealed with paraffin or hot melt adhesive. Battery noise: The failure of the front-stage filter capacitor increases the ripple, which is usually accompanied by a decrease in charging current. In most cases, this can be observed visually after opening: the top of the capacitor is slightly bulging, or there is electrolyte leakage at the bottom.
After driving for so many years, it's quite common to hear a boiling sound when charging the battery. This is usually the electrolyte inside the battery boiling. The main reasons are that the charging current is too high or the voltage is too high, causing a large number of bubbles to form inside the battery, making a hissing sound, somewhat like boiling water. Additionally, battery aging or internal short circuits can also cause overheating and violent reactions in the liquid. This not only damages the battery but can also be dangerous, as excessive gas production can accumulate hydrogen, which may explode if exposed to sparks. Therefore, if you notice this situation, you should stop charging immediately and use a multimeter to check if the charging voltage is within the normal range of around 14V. Regularly inspect the battery's maintenance status, choose an appropriate charger, and be especially careful not to overcharge in hot weather. If you're unsure, take it to a professional auto repair shop for inspection—don't tamper with it yourself and risk safety.
I remember last time when my car battery was charging, it also made a boiling water sound. That hissing noise was really worrying. I think this was caused by overcharging, where the high voltage made the liquid inside the battery boil and produce bubbles. Common causes include improper charger settings, an old battery with internal corrosion, or poor contact. You must disconnect the power immediately to avoid the battery overheating and getting damaged, or even the risk of catching fire. It's best to check if the battery terminals are loose and if the electrolyte level is at the proper height. If it's too low, add water but don't overfill. Also, remember to choose a smart charger that automatically shuts off for safety. Regular maintenance, like keeping it clean and avoiding extreme temperatures, can greatly reduce this issue. It’s more reassuring to have a reliable mechanic check it out—don’t delay and risk affecting your driving.
