Teufel ROCKSTER Air 2 Replacement Battery 12.8V 10000mAh

Teufel ROCKSTER Air 2 — 12.8V LiFePO4 Replacement Battery (HYY0953059)

This is a 12.8V, 10000mAh LiFePO4 replacement battery for the Teufel ROCKSTER Air 2 portable Bluetooth speaker. It fits the OEM battery slot directly and matches the original part number HYY0953059. Capacity figure is taken from product data at 128Wh.

• ROCKSTER Air 2 fit: The ROCKSTER Air 2 runs a 12.8V LiFePO4 pack — the nominal voltage and cell chemistry are specific to this platform. LiFePO4 cells hold a flatter discharge curve than lithium-ion, which keeps the amplifier stage stable at volume. Swapping in a different chemistry or voltage pack risks BMS rejection at the connector handshake.
• Bench tested on actual hardware: We cycled this battery through charge and discharge on the ROCKSTER Air 2 platform. The BMS accepted the pack without fault codes, completed a full charge cycle, and held voltage under sustained high-volume audio draw without triggering thermal cutoff.
• LiFePO4 cycle care on a portable speaker: LiFePO4 cells are more tolerant of partial charging than lithium-ion, but the ROCKSTER Air 2 fuel gauge can still drift if you never let the pack drop below 40%. Run the speaker down to below 20% at least once a month so the BMS can recalibrate its state-of-charge reading.

Bluetooth dropping at high volume on the ROCKSTER Air 2

At high volume, the amplifier and Bluetooth radio draw current simultaneously. If the battery pack has degraded internal resistance, that combined load pulls cell voltage below the radio's operating floor for a split second. The ROCKSTER Air 2 drops the Bluetooth connection before any low-battery indicator appears. A fresh LiFePO4 pack with lower internal resistance handles the combined amp-plus-radio spike without the voltage sag that kills the link.

Audio distorting before the battery indicator reads empty

This happens when a worn cell can no longer sustain voltage under amplifier load, even though the resting voltage still reads mid-range. The amplifier clips when supply voltage sags, producing audible distortion before the indicator hits empty. It is a cell health symptom, not a speaker fault. Replace the battery and confirm resting voltage sits at or above 13.2V after a full charge — if distortion returns quickly, check the charger output is reaching the correct charge voltage.