When faulty batteries are taken to a repair shop and removed, you often find that a battery that was once flat and square has become uneven and badly swollen and deformed. Why does this happen? Based on collected information, we have summed up the main causes of deformation below:

1. An unqualified or mismatched charger

The number of electric vehicles keeps rising, and in some small cities they are an essential means of transport for nearly every household. When the battery runs low, people are not worried and simply borrow any charger to solve the problem in minutes. But have you considered whether that charger matches your electric vehicle battery? Using a mismatched charger to charge is an important and very common cause of battery swelling and deformation. It is recommended to use a charger that matches your electric vehicle battery.

2. Problems with the battery itself

This is mainly caused by uneven acid filling or insufficient acid during production, but such cases are extremely rare.

3. Excessive charging current or over-long charging time

Charging is an exothermic process. When the charging current is too large or the charging time too long, the temperature of the electrolyte rises rapidly and produces a large amount of gas, which loosens and sheds the active material on the plates and causes the battery to swell.

4. Sulfation of the plates

If the battery is not charged promptly after riding, the plates become sulfated. During high-current charging, a sulfated battery sees its cell voltage and electrolyte temperature rise rapidly, with gas bubbles forming early and violently, which easily causes the battery to swell.

5. Electrolyte viscosity that is too high

When the temperature is too low, the electrolyte becomes viscous, seeps into the plate pores slowly, and increases internal resistance, so the voltage drop consumed by internal resistance during discharge is larger. This causes the electrolyte temperature to rise rapidly and produce a large amount of gas, increasing the internal gas pressure. If the battery is then over-discharged, the electrolyte temperature rises even faster and more gas is produced, making the internal pressure even higher and very likely causing the battery to split. In addition, the explosive gases produced during charging can cause an explosion immediately if they meet an open flame, splitting the battery. Therefore, the charging room must be well ventilated, and fire and smoking are strictly prohibited.

6. The electrolyte drying out

After long use, a battery loses water, and the electrolyte can dry out. Overcharging at this point will cause the battery to swell.

In short, when using an electric vehicle, be sure to use it correctly to avoid unnecessary danger, and when choosing a battery, prefer one of high quality, with a good reputation and complete after-sales service.