There are many reasons: excessive current protection, low single string voltage, damage to the protection board, etc. Generally, it is possible that the tension of a single chain is too low.
1) Check if the battery/battery pack has zero voltage or high internal resistance battery.
2) If the electronic components and protection circuits inside the battery are damaged.
3) Check whether the discharge circuit of the equipment is normal.
4) If the pole lug is broken, forming an open circuit.
How to deal with undischarged lithium battery packs:
1) Connect a fully charged battery/battery pack of the same model to the device and check if the device is working properly.
2) Use a multimeter to check whether the electronic components and protection circuits inside the batteryare normal.
3) Repeat the analysis and processing of the zero voltage step of a single cell.
4) If the discharge circuit of the electrical appliance is abnormal, the customer is recommended to repair or replace the electrical appliance in time.
5) If the customer has not modified the battery himself, specialized technical personnel are required for further analysis.