Abstract: Overcharging and over-discharging are common faults in lithium-ion batteries. In the context of the current research, iron phosphate batteries of the same brand and capacity were selected as the experimental subjects. These batteries underwent the same preprocessing procedures before the experiment to ensure uniformity of the experimental conditions. Based on this, a special experiment was conducted: the battery voltage was increased to 1.5 times the termination charge voltage, thereby achieving overcharging of the battery. During the experiment, it was found that although these iron phosphate batteries had the same capacity, there were certain variations in the parameters of the batteries during the fault process caused by overcharging. This discrepancy has, to some extent, affected the final analysis results, necessitating the consideration of these factors when evaluating battery performance and safety. When over-discharging, even when there are no obvious external changes to the battery, it is necessary to monitor its electrical and non-electrical parameters to accurately determine the real-time status of the battery. The electrical parameters that need to be tested include, but are not limited to, internal resistance, charge voltage, discharge voltage, current, and temperature. By detailed recording and analysis of these parameters, we can better understand the different behavioral characteristics of the battery during overcharging and over-discharging processes, providing strong support for the safe use and performance optimization of batteries.