When the electric car is charged, the original eight hours are full, but now it is more than 15 hours or dissatisfied, what is this?

This shows that your battery has poor performance, the charger is to detect the charging voltage to determine whether it is full, the battery performance is poor, the charging voltage is always not up to, the charger is always in the charging state.

After unplugging, the charger will enter the initial self-test state, and the self-test voltage is lower than the charging voltage.