Why is the car battery overheating?
2 Answers
Reasons for battery overheating during discharge: Discharging too quickly, possibly due to a small battery capacity where the discharge current exceeds 0.5C for an extended period. It could be battery thermal runaway. Long-term charging of batteries with high float charge voltage can lead to severe capacity degradation, resulting in thermal runaway. Consequently, gas inside the battery casing may leak, causing the battery to fail completely without any capacity. Another possibility is battery thermal runaway. Long-term charging of batteries with high float charge voltage can cause significant capacity reduction, leading to thermal runaway, which results in gas leakage from the battery casing and complete failure of the battery with no capacity. There is also a chance that your charger is faulty, or the charger and lead-acid battery pack are mismatched, causing battery thermal runaway. If the charger voltage is too high, exceeding the regulation value of the lead-acid battery pack, it significantly increases gas evolution in the battery, leading to thermal runaway.
When I encounter a car battery heating up, my first thought is usually whether it's due to overcharging. A generator voltage that's too high can cause the battery to overheat internally, which is quite common, especially when the charging system regulator of older car models fails. It could also be an internal short circuit in the battery, where damaged separators cause the positive and negative electrodes to come into contact, leading to instant temperature rise. Additionally, high summer temperatures can exacerbate this issue. I've noticed that excessive discharge, such as leaving lights or the audio system on for too long after parking, can also heat up the battery due to excessive internal current causing heat. In terms of handling: if the battery feels hot to the touch, immediately stop the car and turn off all power sources to let it cool down. Afterward, check whether the charging voltage is within the 13.8-14.4 volt range using a multimeter. If abnormal, seek repairs promptly. Preventive measures: regularly clean terminal corrosion, turn off unnecessary electrical devices before parking, opt for maintenance-free batteries for peace of mind, and generally replace the battery every three years or so to avoid risks.
