Polycom SK45L1-G Compatible Battery 7.4V 2200mAh Li-ion

Polycom SoundStation 2W Series — 7.4V Li-ion Replacement Battery (2200-07803-001)

This 7.4V, 2200mAh Li-ion battery fits the Polycom SK45L1-G, SoundStation 2W, and SoundStation 2W EX wireless conference speakerphones. It replaces OEM part numbers 2200-07803-001 through 2200-07804-003 and L02L40501. When the original pack degrades, the SoundStation 2W loses its ability to operate untethered from the charging cradle — this battery restores that function.

• SK45L1-G, SoundStation 2W and 2W EX compatibility: All three models share the same 7.4V two-cell architecture, connector pinout, and BMS handshake protocol. The battery communicates charge state to the base unit, so a mismatched pack triggers low-battery warnings even at full charge — this replacement matches the OEM signalling spec.
• Bench tested on actual hardware: We cycled this pack through the SoundStation 2W charging cradle and confirmed the BMS negotiated correctly with the base unit, charge termination fired at the right voltage, and the protection circuit held cutoff at the low-voltage threshold without false tripping.
• SoundStation 2W discharge cycle tip: Conference phones in meeting rooms typically sit on the cradle all day and only leave it briefly. That constant top-off without a full discharge causes fuel gauge drift. Run the unit off the cradle until it drops below 20% at least once a month to recalibrate the gauge.

Why the SoundStation 2W shows full charge but cuts out mid-call

The SoundStation 2W's fuel gauge relies on coulomb counting, not a direct cell voltage read. If the pack has spent months on constant trickle charge without a full discharge cycle, the counter drifts — the unit reports 100% while the usable capacity is a fraction of that. Under the combined draw of the speaker amplifier and RF transmitter during a live call, voltage sags fast enough for the BMS to trip the low-voltage cutoff. The fix is a full discharge to below 20% followed by an uninterrupted charge cycle to reset the counter.

Audio distorting before the battery indicator reaches empty

As a Li-ion cell ages or partially discharges, its internal resistance rises. Under the amplifier's current draw — highest at loud volumes or during speakerphone echo-cancellation processing — that resistance causes a voltage sag across the cell. The amplifier clips when rail voltage drops below its operating floor, producing audible distortion even while the charge indicator still shows one or two bars. Replacing the pack eliminates the high internal resistance causing the sag. Confirm the new pack is reading above 7.2V at rest before reseating it in the cradle.