Before a lithium battery bulges or leaks, there are usually the following three signals
1. Abnormal temperature rise during charging: When the temperature of the lithium battery‘s casing exceeds 60℃ during charging, and there is a distinct burning sensation when touched by the palm, accompanied by a burnt plastic smell, it is necessary to be vigilant. This might be caused by the use of non-standard fast charging devices, the mixed use of new and old batteries, or charging in high-temperature environments. At this time, abnormal chemical reactions may be taking place inside the battery, which is a precursor to bulging, leakage, or even more serious safety issues.
2. Shell swelling and deformation: If the shell of a lithium battery shows obvious swelling and deformation, and the bulge measured with a ruler is ≥3mm, or there is a "rustling" abnormal sound when pressed, it is very likely that the internal plates of the battery are broken and rubbed, or the safety valve is blocked and the gas cannot be released. Once the shell is found to be swollen and deformed, it indicates that the internal structure of the battery has been damaged, posing a significant safety risk.
3. Sharp reduction in battery life If the endurance of a lithium battery suddenly drops by more than 30%, for instance, a battery with a claimed range of 60 kilometers plummets to less than 42 kilometers, or if the voltage drops by more than 10% after being fully charged for one hour, it indicates that the activity of the chemical substances inside the battery may have decreased, and the battery performance has seriously declined. It is very likely that further problems such as bulging and leakage will occur.