How to test a damaged 18650 lithium battery pack

1. Battery consumption performance: the battery voltage does not go up and the capacity decreases. Measure straight with a voltmeter, if the voltage across the 18650 battery is lower than 2.7V or there is no voltage. Indicates that the battery or battery pack is damaged. The normal voltage is 3.0V～4.2V (generally, the voltage of 3.0V battery will be cut off, and the voltage of 4.2V battery will be fully saturated, and some also have 4.35V). 2. If the battery voltage is lower than 2.7V, you can use the charger (4.2V) to charge the battery. After ten minutes, if the battery voltage rises, you can continue to charge until the charger prompts overflow, and then look at the overflow voltage. If the full battery voltage is 4.2V, the battery is declared normal, it should be because the battery was cut off because of the excessive power consumption last time. If the full battery voltage is much lower than 4.2V, it means that the battery is damaged. If it is a battery that has been used for a long time, it can be judged that the battery life is over and the capacity is basically exhausted. Should be replaced. There is basically no way to fix it. After all, lithium batteries have a life span, not infinite. 3. If the 18650 lithium battery pack is measured and the battery has no voltage, there are two situations at this time. One is that the battery is good, and it is caused by long-term loss of electricity. This kind of battery has a certain chance to recover. Generally, it is activated by pulsed lithium battery. A meter (lithium battery charge and discharge meter) to charge the battery multiple times in a short period of time, it may be repaired. Generally, the repair cost is not low, so you should buy a new one. Another possibility is that the battery is completely worn out, the battery diaphragm breaks down, and the positive and negative electrodes are short-circuited. There is no way to fix this kind of thing, only buy a new one. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous post: Analysis of several vulcanized electric vehicle battery repair methods