Traditional monitoring methods of Li-ion batteries mainly adopt the electric quantity such as voltage and current or the battery evaluation quantity such as SOC and SOH. The timeliness and accuracy were insufficient. In this paper, mechanical vibration is introduced as a new monitoring quantity of Li-ion battery. The vibration mechanism of Li-ion battery is analyzed theoretically. From the experimental point of view, the battery is set to three working states: normal charging, normal discharging and overheat charging, and the vibration signal is collected and compared. And the consistency test was carried to exclude accidents. The study found that the battery has a vibration signal under normal operating states. Under abnormal states, the battery’s main frequency and main amplitude change significantly. This paper provides the basis for the introduction of the vibration monitoring quantity of the battery monitoring system, and provides a new idea for the battery monitoring.