BOOMSTER XL: Are replacement batteries available? Teufel Support September 22, 2022 06:38 Updated Yes! You can find a suitable replacement battery in the accessories: View replacement battery for BOOMSTER XL Related articles BOOMSTER (2020): What is the purpose of the battery switch on the back? General information: Software/Firmware/Driver/Updates BOOMSTER (2020): My Teufel BOOMSTER (2020) does not work in battery mode. ROCKSTER / ROCKSTER AIR: The battery does not charge and/or discharges very quickly. Is this a defect? Can I pair two or more portable Teufel Bluetooth devices with each other?