About this replacement
Sirius XM Satellite Sportscaster — 3.7V Li-ion Replacement Battery (R101BP)
This is a 3.7V, 1400mAh Li-ion replacement battery for the Sirius XM Satellite Sportscaster and XM101WK portable satellite radio receivers. OEM part numbers R101BP and 990280 both cross-reference to this cell. Voltage and capacity match the original specification exactly.
- XM Sportscaster and XM101WK compatibility: Both the Sportscaster and XM101WK share the same 3.7V single-cell architecture, battery footprint, and connector pinout. One battery fits both units without modification.
- Bench tested on actual hardware: We ran this battery through charge and discharge cycles on the XM Sportscaster. The BMS handled charge termination cleanly and held voltage within the stable range the DAB decoder requires for uninterrupted stream processing.
- Post-install station scan on the Sportscaster: After any battery swap that fully cuts power, the Sportscaster loses its stored station list from volatile memory. Once the new battery is installed, let the unit run a full auto-scan before tuning manually — this rebuilds the station list from the satellite signal rather than from empty memory.
Radio cutting out mid-station at low battery on the Sportscaster
The XM Sportscaster's satellite decoder needs a steady voltage supply to process the compressed audio stream without interruption. As a Li-ion cell ages, its internal resistance rises and voltage sags under the RF and decode load — even when the battery indicator still shows charge remaining. That sag pushes the supply rail below the decoder's minimum threshold, causing the audio to drop or the unit to reset. If drop-outs start appearing before the low-battery warning, the cell has degraded and needs replacement.
Reception worse after replacing the battery
Satellite radio receivers increase RF front-end power draw when signal strength is marginal — the tuner works harder to lock onto the XM signal. A new battery that hasn't reached its first full charge cycle may show slightly suppressed capacity and cause the unit to throttle RF output to protect the cell. Charge the battery fully before use in a fringe-signal area. After a full charge, check signal strength in the unit's diagnostic menu — it should read above the minimum lock threshold for your location.