Why does the battery get hot during charging?
4 Answers
Car battery and charger mismatch, causing the electric vehicle battery to heat up during charging. Here is some information about car batteries: 1. Function: Car battery, also known as a storage battery, is a type of battery that plays a crucial role in the operation of a car. If the car battery fails to supply power normally, the engine will encounter problems. Car owners should regularly inspect their batteries—weekly in summer and biweekly in winter. 2. Factors affecting battery lifespan: Vehicle condition, road conditions, and driver habits; good driving habits can extend the battery's service life.
My car battery used to get extremely hot while charging, to the point of being too hot to touch. After checking it myself, I finally found the cause. It's normal for a battery to get a little warm during charging due to the heat generated by chemical reactions, but excessive heat is not a good sign. It could be due to a faulty charger that's set to too high a voltage, causing overcharging and making the battery boil inside. Alternatively, the battery might be old—after several years of use, internal short circuits can occur, leading to unstable current and increased heat. Another time, I found that the battery terminals were loose, causing poor contact and increased resistance, which converted electrical energy into heat and wasted it. I recommend starting with the simple checks first: inspect the charger and the connections. If the battery continues to overheat, stop charging it immediately—it's safer to replace the battery rather than risk damage or even an explosion. Always use a standard charger and avoid charging in high-temperature environments—these are lessons I learned the hard way.
Battery heating during charging is usually normal, but it shouldn't get too hot to touch. As someone who frequently works with car model modifications and has some basic knowledge: The chemical reactions inside lead-acid batteries generate heat during charging. If the voltage is too high or the current too strong, heat production increases dramatically. Possible causes include incorrect charger settings, internal short circuits in the battery (such as damaged separators), or increased resistance due to battery aging. Additionally, environmental factors like charging during hot summer days can accelerate heating. From what I've read, severe overheating may cause electrolyte evaporation and damage battery lifespan. If this occurs, immediately disconnect the power and use a thermometer to check surface temperature - be cautious if it exceeds 60°C. I recommend using a reliable multifunctional charger with protection features, regularly testing battery voltage, and keeping the battery clean to reduce failure risks.
I've encountered battery overheating during charging several times, all happening with older vehicles. Normally it should be slightly warm, but if it becomes unbearably hot, it usually indicates the battery is failing - internal aging or increased short-circuit resistance. An inaccurate charger voltage can also contribute to the problem. With years of driving experience, I know this issue shouldn't be taken lightly - excessive heat can burn out components or even cause fires. It's best to immediately check for loose wiring connections and try a new charger. Avoid prolonged fast charging in daily use and maintain garage ventilation for cooling.
