1. Long-time overcharge

Long-time overcharging and overcurrent of batteries can lead to high temperature and high voltage, which can easily cause

battery bulging causes damage to the internal structure, thereby triggering the heat of the battery runaway.

2. Excessive ambient temperature

It refers to the maximum internal heat of the battery. In summer, the temperature is high. If the battery is exposed to direct sunlight for a long time, or if it's over-charged, it will be under high temperature conditions. The battery temperature will rapidly rise, making it prone to overheating and bulging, which can lead to uncontrolled heating.

3. Using mismatched chargers

Many users of lead-acid electric vehicles will continue to use their previous chargers when replacing their lithium batteries by themselves. But the voltage of lead-acid chargers is generally higher than that of lithium chargers. If a lithium battery is charged at this voltage, there is a risk of overvoltage. In severe cases, it can directly ignite. Some consumers even blindly purchase high-power chargers that do not match electric bicycles in order to reduce the number of charges, which is very dangerous.

4. Lithium battery water ingress

In addition to the battery cells, there're also BMS inside lithium batteries. If a user's riding an electric vehicle through water and gets it wet, the BMS may malfunction, and in severe cases, it may cause a short circuit and self ignition.

If the water intake is limited and there is no problem in the short term, the rusting and corrosion caused by water intake may lead to short circuit and spontaneous combustion over time. If lithium batteries are flooded, it is necessary to find a professional testing point to inspect and maintain the battery.

5．Charged under low temperature

If your battery does not have low-temperature protection and is often charged in a low-temperature environment, there is a certain risk. Because as the temperature decreases, the dynamic characteristics of the negative electrode further deteriorate. During the charging process, the temperature of the battery pack will increase, but the external environment is in low temperature. If the temperature difference is too large, it can cause chemical reactions of active substances on the anode and cathode plates, weaken the ability of the negative electrode to embed lithium ions, accumulate and form lithium dendrites, which can easily short circuit and affect the lifespan, capacity, and performance of lithium batteries. In severe cases, it may lead to uncontrolled heating!

6. External damage causing battery short circuit

The external damage of the lithium battery causes the battery separator to be punctured. Direct contact between the positive and negative poles will cause a short circuit inside the battery, releasing a large amount of electrical energy in a short period of time, leading to thermal runaway of the battery.