Portable wireless speaker Applicable to USB,SD/MMC card,computer,mp3,mp4,mobile,ipod,iphone Built-in lithium battery,recharge Digital MINI card small ... Built-in 800 MAH,3.7-volt lithium battery.You can use rechargeable or external power adapter USB charging voltage of 5 volts ... powerFrequency responseSNRCharging timeWorking Hours6 watts20-20KH2>85dB1-2 hours4-5hours wireless USB laptop speaker