How long can a Travelcube be operated after being fully charged? March 31, 2025 15:15 Updated A fully-charged Travelcube sound machine should be usable for at least eight full hours. Related articles What do the flashing LED lights on the Travelcube sound machine mean? What do the green and amber lights on the Soundcenter indicate? What does the "ding" sound mean? Can the 120V Dohm be used in US military bases in Europe?