battery light on 2001 Chevrolet Malibu

I have had the battery replaced & the altenator replaced but the battery light comes on whenever I slowdown or stop. The battery is completely dead after 1 day of driving in town

Asked by for the 2001 Chevrolet Malibu
Have the charging system checked out. This can be from a loose battery cable or something else, but only a proper diagnosis of the system will determine that.