What's wrong with the battery charge?

2020.10

This is the existence of safety redundancy in the battery, reserve a part of the power to prevent the battery overcharge and excessive discharge.For example, the original battery capacity is 100%, but the actual battery capacity is about 80%-90%, and the value after the power redundancy is the actual power that the car owner can use.Because during the charging process, the battery can't be too full, nor can it be discharged into space.If the battery is fully charged every time, it will greatly reduce its service life;Charging too full, once the charging system has a fault, it is possible to cause safety accidents because of "overcharging".