Directly charge the lithium battery without passing through the protection plate, that is, directly charge B+ and B- of the lithium battery. If it can be charged, it can be guaranteed that the lithium battery is normal without switching. through the protection plate.
Replace the protection panel. If the new protection board is replaced and the battery can be charged, but the old protection board cannot be charged, it means that the protection board of the previous lithium battery is defective.
If it is a problem with the lithium battery protection board, most of the time it is because the charging MOS of the protection board is defective, or the charging fuse is broken by large current, or the integrated circuit of the lithium battery protection board is damaged.
Solution: Lithium battery protection board falls into panne, which prevents the lithium battery from charging. The most direct solution is to replace the protection board with a new one.
If there is no completely new protection board, you can detect the specific fault points of the protection board, such as MOS tubes, resistors, capacitors, circuits Built-in fuses, fuses and other components, detect the specific fault points of the protection board, and then compare them accordingly.