Note: This article refers to the BOOMSTER (2020), sold from 2017 to 2021. This model has a down-fire subwoofer.
Yes, it is possible to operate the device without the battery. With the battery removed, simply connect the unit to its power cord and turn on the BOOMSTER (2020) at the power switch on the top panel.
Battery care tips:
Before removing the battery, first fully charge it, then remove it and place it in a dry place at room temperature.
Install the rechargeable battery approx. every 3 months and charge it fully again so that it does not become deeply discharged in the meantime. This protects the battery and ensures a long battery life.