Ant protection board can not charge and discharge reasons: 1, battery imbalance --------- one battery or more batteries reach the overcharge protection voltage of the protection board.
2. The mos of the charging direction of the protection board is broken. 3. The protection IC is broken.
4. The device between IC command mos is broken.
5, the NTC resistance of the protection board is bad or the resistance value is wrong -- leading to the IC that the battery is in a high temperature state ---- prohibit charging.