About this replacement
Philips 218 / 288 / 268 Series — 3.7V Li-ion Replacement Battery (BHS205P)
This is a 3.7V 650mAh Li-ion cell built to the BHS205P specification. It fits the Philips 218, 288, 268, and FISIO-268 handsets, along with three additional models in the same series. The connector, BMS handshake, and cell dimensions match the original factory configuration.
- 218 / 288 / 268 platform fit: These models share the same battery bay geometry, 3.7V nominal rail, and BMS communication protocol. One cell revision covers the full group — no adapter or modification needed.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a 218 handset. The BMS accepted the cell without fault codes, and the charge IC completed a full CC-CV charge sequence to 4.2V without thermal event or cutoff error.
- Fuel gauge recalibration on first use: After fitting this cell, run one complete discharge to automatic shutdown, then charge uninterrupted to 100%. The phone's fuel gauge IC was calibrated to the old cell's discharge curve — this single full cycle resets the coulomb counter against the new cell so percentage readings stay accurate.
Sudden shutdown at 20–30% on the Philips 218 after a cell swap
A new Li-ion cell has a slightly different voltage-versus-capacity curve than the degraded cell it replaces. The phone's fuel gauge IC reads voltage drop under screen or radio load and maps it to a stored discharge table — one calibrated to the old cell. When the new cell's voltage dips briefly under transmit load, the IC interprets it as a near-empty condition and triggers shutdown, even though usable charge remains. This is not a faulty cell. One full discharge-charge cycle rewrites the coulomb counter reference point, and the shutdowns stop.
Phone shows incorrect battery percentage after fitting the BHS205P
The fuel gauge IC on these Philips handsets stores a charge curve profile in non-volatile memory. When you swap the physical cell, that stored profile still references the old cell's internal resistance and self-discharge rate. The result is percentage readings that jump, stall, or plateau — typically freezing somewhere between 40% and 80% before suddenly dropping. Discharge the phone fully until it powers off on its own, then charge to 100% without interruption. After that single calibration cycle, the IC recalculates against the new cell and percentage tracking stabilises.