What are the reasons for battery overheating?

[DeHarper]

Battery overheating is caused by excessive current during operation. The functions of the battery are: 1. When starting the engine, the battery supplies power to the starting system, ignition system, and electronic fuel injection system; 2. When the engine is stopped or idling at low speed, it powers the vehicle's electrical equipment; 3. When the generator's output is insufficient, it can assist in supplying power to the electrical equipment; 4. It mitigates voltage surges in the electrical system, protecting the vehicle's electronic devices; 5. It can store excess electricity generated by the alternator. Battery maintenance methods: 1. Avoid parking the car in an open-air parking lot for extended periods; 2. In winter, avoid multiple uninterrupted starts of the car; 3. The car battery should be charged frequently; 4. Regularly clean the battery terminals and apply grease to protect the wiring harness.

[OscarLee]

I've been driving for most of my life and have encountered battery overheating issues several times, which can be really troublesome. There are multiple causes: overcharging is a major factor—if the alternator or voltage regulator fails, it keeps charging the battery nonstop, making it hot; short circuits are also common, where internal corrosion or external wiring causes excessive current flow, leading to instant heat; aging batteries with damaged plates inside generate heat; parking in direct sunlight during summer makes batteries more prone to heating up; and frequent engine starts or using high-power devices like audio systems or air conditioners can overload the battery, making it hot. I remember last summer during a long drive, I didn't pay attention, and the battery got dangerously hot, almost catching fire. It turned out to be a charging system issue, and replacing the regulator fixed it. To avoid danger, regularly check the battery's condition—like watching for abnormal charging indicator lights—and if the temperature seems off, pull over to let it cool down.

[SanMargaret]

As a mom who often drives out with kids, I pay special attention to vehicle safety. Common causes of battery overheating include overcharging, which means a faulty alternator can cause the battery to overheat; short circuits are also a significant issue, possibly due to internal corrosion or external wiring touching, leading to a surge in current and heat; an old battery with degraded performance is more prone to heating up; parking the car outdoors in high temperatures can exacerbate the problem; running the air conditioner or frequent engine starts and stops can also overload the system. Once during a trip, the battery got so hot it scared me. Later, a friend taught me simple ways to check, like feeling for abnormal temperatures or observing if the voltmeter readings exceed normal levels. Now, I park in a cool spot in the garage and regularly clean the battery terminals to avoid trouble. Safety first—if something seems off, don’t push it. Turn off the engine to cool down and seek help if needed.

[Cody]

I'm a DIY car repair enthusiast and often tinker with my vehicle. I have experience with battery overheating. The main reasons include: overcharging—check the generator regulator to see if the voltage is too high; short circuits—poor internal electrode contact or a sudden surge in external short-circuit current; battery aging—increased internal resistance causing heat; high ambient temperatures leading to faster natural heating; and heavy usage like repeatedly starting the engine, which drains a lot of power. A simple troubleshooting method is to measure whether the battery voltage is too high and use a multimeter to test for abnormal circuit conductivity. If issues are found, replace the faulty parts or clean corroded points. Regular maintenance, such as cleaning electrode connections and avoiding moisture, can prevent most overheating problems.