600 mah Li-Polymer Battery! Average of 8 - 10 hours of play with a full charge! A full charge takes about 2 hours! Used the Bluetooth Transmitter to transmit audio from a TV to a wireless headset. Used the Bluetooth Receiver to make your hardwire headphone, speaker, car stereo or headset have Bluetooth capabilities to pair to a Bluetooth device, such as a smartphone. Your audio transmission master: Used for all audio interface devices like TV, PC, CD Player, etc. Real-time low latency and high-quality audio transmission. Receive Mode: Easily connect/pair to a phone and transmit audio to our Bluetooth Audio Interface, which is connected via 3.5mm/Aux Jack or RCA to your headphone, speaker, car stereo or headset.