Why does the electric vehicle battery charge hot?

Electric vehicle charging is a process of exothermic heat, so the battery tends to get a little hot when charging. But sometimes the electric vehicle battery will have abnormal heating during charging, which often leads to a shortened battery life. So, why does the electric vehicle battery experience excessive heat? There are two main reasons: 　　 First, the battery is aging, the internal resistance becomes larger, the electrolyte is dried up, and the internal short circuit is caused by the battery's own problems. With the increase in the number of times the battery is used, including discharging and charging, the water molecules in the battery are gradually lost, which causes the battery to generate heat in the electrochemical reaction; in addition, the battery solution forms sulfuric acid crystals during the charging and discharging process, and the precipitate sticks to the plate. If the battery heats up due to a short circuit, the best way is to replace the battery with a new one.　　　　 2. Fever caused by charger problem. General chargers do not have the pulse function, nor the negative pulse elimination function. This type of charger usually cannot maintain a constant voltage in the later stage of the charge, which will cause the battery voltage to exceed the allowable value, resulting in a large amount of gas out of the battery, loss of water, and heat. When the battery generates a small amount of heat, it is normal heat. If the heat is abnormal, it is the cause of the charger when the battery performance is good.　　 In addition, you must strictly follow the manufacturer's instructions during the charging process, especially the charging time. It is not that the longer the charging time, the greater the capacity. Excessive time may damage the battery or even cause a fire. However, too little time and frequent charging and discharging will also cause considerable damage to the battery. Previous: What should I do if the battery of an electric car is swollen?