Why does the battery get hot during charging?
3 Answers
There are several reasons why the battery gets hot during charging, including battery issues, aging, and increased internal resistance. Reasons for overheating: As the battery is used more frequently, water molecules within the battery gradually deplete, leading to gas evolution and water loss, which causes the battery to heat up during electrochemical reactions. Additionally, during the charging and discharging process, the battery solution forms sulfate crystals that adhere to the lead plates, increasing the battery's resistance and causing it to heat up. Charging in high-temperature environments, such as under direct sunlight, can also contribute to overheating. The already high ambient temperature, combined with the heat generated by the battery and charger, exacerbates the issue. Battery replacement: Problems like battery aging and increased internal resistance can be addressed through technical solutions such as adding water or desulfurization. However, if the battery heats up due to short circuits or broken grids, it is best to replace it. Batteries older than two years should be checked regularly. Generally, car batteries have a lifespan of 2 to 3 years, while the original battery in a new car can last more than 3 years.
As someone who frequently tinkers with cars, I've found that a hot battery during charging is no small matter. Normally, a battery will heat up during charging due to the heat generated by chemical reactions, but if it feels excessively hot to the touch, there's a problem. This could be due to battery aging or an internal short circuit, increasing resistance and causing a sharp rise in heat. Alternatively, the charger might be improperly set, delivering too high an output current that exceeds the battery's capacity. Another factor is high ambient temperatures; charging in summer can make the battery heat up more easily. I recommend stopping the charge immediately, letting the battery cool for an hour, and checking if the charger's parameters match the car's requirements. Don’t ignore this—it could lead to fire or explosion. Safety first. Regularly check the battery's lifespan and use a thermometer to monitor its surface temperature; keeping it below 60°C is generally acceptable. If it exceeds that, visit a professional shop for a replacement—don’t skimp and risk damaging the entire vehicle system.
As a car owner myself, I've encountered the situation where the battery felt warm during charging, which scared me so much that I didn't dare to touch it. After asking friends, I learned that it's normal for the battery to be slightly warm during charging, but if it's as hot as a freshly boiled pot, that's an abnormal signal. Common issues include prolonged charging time or battery aging, which generates extra heat internally. When checking, first unplug the charger and use a multimeter to simply measure the voltage—batteries with too high voltage are prone to overheating. Additionally, poor contact at the charging port can cause unstable current and increase heat generation. I later switched to a smart charger that automatically controls the current, reducing risks. Remember to charge in the garage and avoid direct sunlight on the battery location—this method works well. Don't wait until it explodes to take action; a small preventive investment brings peace of mind. Learning some DIY skills, like regularly cleaning the terminal connections to prevent oxidation and poor contact, can save a lot of hassle.
