You can try the following solutions.
The first activation method can try fast charging, in short, push the electric vehicle to the fast charging station for two hours. When the charge is finished. Use a multimeter to measure, if the voltage rises, then use the original charger to charge, so that in general, the battery can be activated.
The second activation method can be parallel repair method, as the name suggests is to find a group of new batteries with the same primary battery model, and the new battery and the old battery in parallel, and then through the new battery discharge, after several rounds of cycles, the old battery performance will slowly recover, and there is a certain probability that it can be reactivated.
The third activation method can be used to charge the small, that is, to charge the small power charger first, and then use the original charger to charge. Taking 72V electric vehicles as an example, a 60V charger can be used to charge for half an hour, and then the original 72V charger is used to charge, so there is a certain chance that the battery can be reactivated.
Of course, not all electric vehicle batteries can be activated again, and for some batteries that have been seriously aging, the repair effect is no longer obvious. In addition, even if the old battery can be activated again, its performance can not be restored to the original best state, generally around 70%.
Should be serious battery damage caused by power loss.
There are several possible scenarios
1, a long time of power caused by the fuse burned out, if the fuse is broken due to a long time of power, go to the maintenance point in time to check the repair or replace the new, inexperienced novice do not do it yourself to avoid other problems.
2, poor contact, the reason for the charger, when the charger can not charge, but the indicator light is still on, we will mistakenly think that we have been charging, you can change a charger with the same power voltage to try.
3, battery aging, when the battery aging problem, there is no repair problem, basically can only be scrapped for new.
4, circuit board failure,
When the circuit board in the dial is broken, it will also cause the battery to be charged, as long as the replacement or repair of the circuit board is good.