About this replacement
Yealink CP925 / CP935W / CP960 / CP965 — 3.7V Li-ion Replacement Battery (YLLR1865C7800WLS)
This is a 3.7V, 7800mAh Li-ion battery for the Yealink CP925, CP935W, CP960, and CP965 portable conference phones. It replaces part number YLLR1865C7800WLS when the original cell degrades and the unit can no longer hold a charge through a full meeting. Fitting this battery restores wireless operation so the unit is no longer tethered to a power outlet.
- CP925 / CP935W / CP960 / CP965 platform fit: These four units share the same battery cavity dimensions, connector pinout, and BMS communication protocol — the same pack services all four without modification.
- Bench tested on actual hardware: We cycled this pack under sustained audio and wireless draw simultaneously. The BMS held voltage within the expected window and did not trigger a premature cutoff under combined load.
- First-session calibration: After installing, run a full charge cycle before the first meeting. Conferencing units map battery state during normal operation, and the indicator may show inaccurate warnings for the first session after a swap until the system has completed one full cycle.
Battery indicator showing wrong level after installation
Yealink conference units use voltage-threshold mapping to estimate charge level — they do not recalibrate automatically when a new pack is fitted. After a battery swap, the unit reads the new pack's resting voltage and assigns a charge percentage based on its stored curve, which may not match the actual state of charge. This produces misleading warnings or incorrect percentage readings on screen. One complete charge cycle from flat to full forces the system to re-anchor its reference points and restores accurate indicator behaviour.
Wireless connection drops mid-meeting after battery swap
The CP925 and CP935W run both the audio codec and the wireless radio from the same battery rail. Under peak combined draw — loud room audio plus active wireless transmission — voltage can sag briefly below the radio module's operating floor, causing it to drop the connection. This is more likely with a battery that has been sitting in storage and has not been conditioned. A full charge cycle before first use stabilises the pack's internal resistance and reduces sag under peak load. If drops continue after conditioning, check that the pack contacts are fully seated and free of debris.