Star Shape 3 USB Port 13000mAh power bank use for anyone. Due to the large capacity, it takes almost 4 to 5 hours before it gets fully charged but once it is full you can safely use it for a few days. The charging speed also depends on the charger. We tested it with a charger that can supply 1.2A (amps). If you use it with a charger that can supply 2A or more, it will charge faster.