Products with rechargeable batteries have limited delivery options. The Therm-Ic power bank is connected to the product via the USB port. The power bank's own battery is charged through a micro-USB connector. Thanks to the USB port, this also works as a general-purpose power bankyou can use it to charge your phone or action camera. By using a Bluetooth connection, you can conveniently select the desired power setting for heating the jacket or vest via a mobile app. - Four LED lights indicate the battery charge level - Charging power management: the power bank's electronics adjust the charging current, maximum level 2.1 amps - Without Bluetooth, maximum power setting: 4 h 30 min - Bluetooth, setting 1: 11 h - Bluetooth, setting 2: 9 h - Bluetooth, setting 3: 7 h 40 min - Bluetooth, setting 4: 6 h 20 min - Bluetooth, setting 5: 5 h 20 min - Bluetooth, setting 6: 4 h 30 min