I charge it before every class just to be safe so I'm not sure how long the battery life really is, but since I use this for work I'm not willing to go without charging it before class, the only issue I have is that turning it off can be annoying because it wants you to hold the button down for an extended amount of time and it flashed blue before red so it can be confusing
Specifications: Bluetooth V3+EDR, Class 2 Support A2DP V1.2 stereo Powered by USB 5V DC Transmission Rate:3(Mbps) Built-in microphone Transmission distances of up to 10M Support Bluetooth hands-free function Wireless music receiver connects to 3.5mm headphone jacks Use with home stereos/speakers, car stereos, headphones etc Functions: 1.Make your Car AUX audio sytem and Home Theater AV HiFi Surrounding system become bluetooth compatible, get music from bluetooth enable device 2.Simply connect this bluetooth audio receiver to your line-in or auxiliary input on your speakers and enjoy the wireless music revolution 3.Whether you want Bluetooth convenience in your car, through your home-theater system, in your kitchen, bathroom, or bedroom, etc. 4.3.5mm male to male audio connector or cable to connect the speakers and receiver Operation: 1.Power on/off Power on: Press and hold the ON/OFF button for 5-7 seconds until you hear a "ready for connecting or a sound" Power off: Press and hold the ON/OFF button for 4-5 seconds until you hear a "Long be or red led" 2.Connect the receiver to your speakers 3.Pairing Pairing: Press and hold the ON/OFF button for 7 seconds until you hear the "Ready for connecting or a sound". The LED indicator will flash between red and blue alternately. Activate your mobile phone's bluetooth function and search for available Bluetooth devices Selet "BT310REV or DL-LINK" from the list When paring is completed, the voice report "connected or short bebe" The LED indicator will flash Blue alternately Package includes: 1 x Bluetooth Music Receiver Built-in Mic 1 x Micro USB Power Cable 1 x 3.5mm Stereo Inlet Socket 1 x User Manual Simple operation, normal car speaker become hands-free Bluetooth speaker magically, portable for vehicle mounted systems. Give you the better product experience.