About this replacement
Snom C620 SIP Wireless Conference — 7.2V Ni-MH Replacement Battery (BT200660)
This is a 7.2V, 3600mAh Ni-MH replacement battery for the Snom C620 SIP Wireless Conference speakerphone. It slots into the C620 to restore cordless operation for IP-based conference calls and multi-participant meetings. Matches the OEM part number BT200660 and the original voltage and capacity spec.
- C620 platform fit: The C620 runs a 7.2V Ni-MH cell pack with a specific connector orientation and BMS handshake tied to the charging dock. This replacement matches that cell configuration, so the dock recognises the pack and initiates a normal charge cycle without fault codes.
- Bench tested on actual hardware: We ran this pack through the C620's charge dock and confirmed the BMS accepted the battery, completed a full charge cycle, and reported correct charge status on the unit's display. No thermal events or charge rejections occurred during testing.
- First-session calibration after swap: After installing, run one complete charge cycle before your first meeting. The C620 maps battery state through normal charge and discharge — until that cycle completes, the on-screen indicator may report an inaccurate level. One full cycle corrects it.
Battery indicator showing wrong level after installation
The C620 uses a voltage-threshold method to estimate charge level. A new Ni-MH pack ships in partial discharge, so the unit has no calibrated reference point yet. The indicator reads whatever voltage it sees at startup and maps it to an approximate percentage — often too low or inconsistent. Dock the unit, let it charge fully to 8.64V (end-of-charge for a 7.2V Ni-MH pack), then discharge through a normal session before trusting the display.
C620 not turning on after battery swap — dock shows no charging activity
If the pack sat in storage for an extended period, cell voltage can drop below the BMS re-initialisation threshold — typically under 6V for a 7.2V Ni-MH pack — and the dock's charge controller will refuse to begin a normal charge cycle. This is a deep-discharge lockout, not a failed battery. Place the unit in the dock and leave it for 30–60 minutes without pressing power; most C620 docks apply a low-current recovery charge below the cutoff threshold. Once cell voltage recovers above 6V, the dock switches to normal charge mode and the unit will power on.