1. The first activation method:
Find a group of batteries with the same model as the primary battery, and put it in parallel with this group of batteries that cannot be charged, so that the good battery discharge to the battery that cannot be charged, after several cycles of parallel charging, there is a certain probability that the battery can be reactivated.
2. The second activation method
Use a small charger to charge this set of batteries first, and then change the original charger to continue charging. For example, the battery that can not be charged is 60V, you can first charge it with a 48V charger, and then change to the original 60V charger for charging, so that there is a certain probability that it can be activated.
3. Third activation method
You can try to quickly charge for one to two hours, and use a professional detector to see if the voltage rises. If there is an increase, you can choose to continue charging with the original charger, so that the battery can be activated.