Why is the lithium battery bulging?

Many people feel that when the battery on the car is out of order, when the battery pack is removed and opened, the battery will have a drum kit, and sometimes it will be severely deformed.

Longitudinal look at some of these cells in the year, some even during the warranty period, why is this so?

Actually there is nothing special this mysterious thing, or not? And then look down, two minutes is enough:

Reason one: when charging the battery is the lead sulfate on the positive and negative plates and the water in the electrolyte chemical reaction, thus make the positive plate back into lead oxide, negative plate back into pure lead.

When the battery cell voltage reaches 2.3V or higher, the battery will evolve gas (the gassing voltage of the lead-calcium plate is 2.3V, and the gas-discharging voltage of the lead-bismuth plate is 2.35V). Everyone knows that when the water is boiled, the water vapor is very hot, and the power is very large. You can start a train (steam car). This theory uses the same for our batteries. When the gas is released, the battery temperature will increase. At the same time, if a large amount of gas is released, there will be insufficient space inside the battery to store the gas, which will cause the battery to swell.

Reason two: The internal resistance of the battery is too high. When the internal resistance of a battery is too high, when the current is constant, the voltage will be high (voltage = current * resistance). What we can see is that the red light has not jumped to the battery when it is normally charged. It is very hot, that is, the battery has not reached the charging voltage, and it will be degassed in advance!

Reason three: The electric vehicle charger not meeting the requirements. When the electric vehicle charger parameters we use are higher than the voltage and current parameters of our battery, it is possible to charge the battery!

Intimate tips:

One: Use the electric vehicle charger that meets the requirements, you can go to the battery repair point to do a special charger test. Many places are now free to detect!

Second: Regularly check the battery and maintain the battery, which can extend the battery life and increase the service life of the electric vehicle!

Three: It is not advisable to charge for a long time!

The page contains the contents of the machine translation.