A Powerful heysong reverb onn speaker for 40 Hours of Non-Stop Bluetooth Music. Enjoy the autonomy of a built-in 5000mA 18650 battery and what it means for your experience as a user of ion bluetooth speaker. The autonomy is so great, that, depending on the volume level, type of audio, and use patterns, this Bluetooth Party Speaker can keep playing your favorite music via Bluetooth for up to 40 hours! Over the past few years, smart speakers have somewhat surpassed portable Bluetooth devices in popularity. Nevertheless, high-end Bluetooth speakers like the JBL Xtreme 3 are still highly sought after.