Why does battery charge fast and also discharge fast ?

A. Poor welding connection with cells in parallels . For example, the number 8S of the 10S4P battery pack has a cell that is falsely welded, so the number 8S cell is equivalent to only 3P, then the 8S cell group will be charged and discharged faster than other cells .

B. After one hundred cycles, or if the battery is discharged to close to 0V, the capacity of the battery pack will be reduced.

C. The battery pack is seriously unbalanced.

D. The design of the battery pack assembly process is unreasonable. For example, connecting two battery cells with a longer wire or a thinner nickel strip which may caused a large difference between the detection voltage from the BMS and the battery cell voltage,which resulted in an overvoltage during charging. Protection, under-voltage protection occurs in advance of discharge.