Aastra 660177 Cordless Phone Replacement Battery 3.7V 650mAh

Aastra 660177 — 3.7V Li-ion Replacement Battery (BKB 201 010/1)

This 3.7V 650mAh Li-ion battery replaces the original pack in the Aastra 660177 and 660177/R1C cordless DECT handsets. It matches the OEM voltage and physical footprint, so no modifications are needed during installation. Compatible OEM part numbers include BKB 201 010/1, FA01302005, and FA83601195.

• 660177 and 660177/R1C handsets: Both models run the same 3.7V single-cell Li-ion rail and share an identical battery bay and connector pinout. One battery covers both variants without adapters or wiring changes.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the 660177 platform. The BMS accepted charge from the base station immediately and held voltage within the handset's operating window across the full discharge curve.
• First charge after installation: Li-ion cells in DECT handsets ship in a partially discharged state. Place the handset in the base cradle for a full uninterrupted charge cycle before making calls — this allows the BMS to calibrate the top-of-charge threshold correctly.

Talk time shorter than original battery after replacement

A new Li-ion cell often reports lower capacity on the first few cycles because the BMS hasn't yet mapped the full voltage swing of the new cell. The handset's fuel gauge is calibrated against the old, degraded pack, so initial readings can be pessimistic. Run two or three full charge-to-discharge cycles and the BMS recalibrates to the new cell's actual 650mAh capacity. If talk time remains short after five cycles, check that the handset sits flush in the base — poor cradle contact limits charge current and leaves the cell partially filled.

Base station not charging after battery swap

Some Aastra base stations use a voltage-sense circuit before committing charge current — if the new cell arrives below roughly 3.0V from storage, the base may show no charge indicator at all. Remove the handset, leave it out of the base for 30 seconds, then reseat it firmly. If the charge light still doesn't appear, confirm the battery connector is fully clicked in, as a partially seated connector breaks the sense circuit before the charging stage even begins.