Operated the Bluetooth Box TT-SK02 is confirmed with a rechargeable battery, the TaoTronics a term of up to ten hours. Here, the battery is not permanently installed in the device, but can be removed if necessary. This is a lithium-ion battery with 3.7 volts and a capacity of 1500 mAh (noted on the battery). It remains open whether the battery is sold separately - a serial number called not TaoTronics. Per USB can charge the battery, which can last, depending on the charging voltage up to several hours (2-3). An appropriate USB cable (Micro-USB to USB) is enclosed. Also included: An adapter cable (3.5 mm jack to 3.5 mm jack) for audio sources without Bluetooth function. Buttons for direct operation, a microphone for telephone calls and an NFC module has built at the top TaoTronics. The middle button starts or stops the Bluetooth playback or takes if a Bluetooth telephone has been paired answers a call. With the remaining keys to regulate the volume, or play next / previous title. For good sound vouch two drivers that are loaded with an output power of three watts. The Bluetooth range is 10 meters, which makes them ideal anywhere. Connectivity is great with a Android / IOS-powered system. The NFC module facilitates the establishment of a Bluetooth connection: smartphones with NFC technology must be kept short to the appropriate place on the box to set up or end the connection to connect. Design pleasant, rubberized haptics, ordinary processing, the sound is astonishingly clean and full. For this price a sound bargain! Purchase recommendation