▅ Unable to discharge

It's maddening to find that a lithium-ion battery pack can't be discharged when it's just assembled and ready to use. After all, the joy of the assembly just now was pouring cold water on the discharge problem before it dissipated.

There are the following points for reference and investigation regarding why the lithium-ion battery pack cannot be discharged. The low voltage of the lithium-ion battery pack triggers the protection function of the protection board or the controller; the same will happen if the protection board or the controller is damaged. As a result, the positive and negative electrodes of the discharge are reversed.

In addition to real problems inside the Li-ion battery pack, careless behavior in checking whether the line is disconnected and whether the switch is open can also cause the Li-ion battery pack to fail to discharge.

▅ Charging failure

The charging failure includes the inability to charge and fully charge. The lithium-ion battery pack cannot be charged when charging. The possible reasons are that the charger is reversed or the charger is faulty; the protection of the protection board is not restored, or the protection board is defective; the battery pack and the electrical appliance are externally disconnected.

During the lithium-ion battery pack cycle, the charging stops before the overall cut-off voltage of the battery pack is reached. The reason for this failure to be fully charged is that the single-string power or capacity of the battery pack is inconsistent. The high-power or low-capacity ones are fully charged first and protected by the protection board so that the batteries of other strings are not fully charged and stop the charging process.

▅ Short use time

Lithium-ion battery packs are discharged quickly after being fully charged for actual use. The main reasons for this happening are that the lithium-ion battery is not fully charged; the voltage capacity of a single string varies considerably; the battery pack is micro-short-circuited, or the battery pack self-discharge is large, which causes the battery pack to be consumed as soon as it is fully charged.

▅ Abnormal temperature occurs

When the lithium-ion battery pack is charged or discharged, the temperature is abnormal and becomes abnormally hot. If this happens for a long time, it will significantly impact the safety, stability, and service life of the lithium-ion battery pack.

Regarding the reason for this abnormal temperature, it is very likely that the consistency of the lithium-ion battery pack is poor, there is a high internal resistance battery in the lithium-ion battery pack, or there is a micro-short circuit in the battery pack, which leads to the lithium-ion battery pack. The temperature of the battery pack is abnormal during charging and discharging.