Philips Norelco QC5055 Replacement Battery 1.2V 700mAh

Philips Norelco QC5055 / BT5270 — 1.2V Ni-MH Replacement Battery

This is a 1.2V 700mAh Ni-MH cell that fits the Philips Norelco QC5055 and BT5270 cordless shavers. It powers the motor that drives the cutting head during cordless use. When the original cell degrades and no longer holds a charge, this replacement restores full cordless operation.

• QC5055 and BT5270 compatibility: Both models run the same 1.2V motor rail and use the same physical cell format — 43.50 × 10.50 × 10.30mm. The charging circuit expects this voltage and cell chemistry, so swapping to a different voltage or chemistry will trip the protection circuit or damage the board.
• Bench tested on actual hardware: We cycled this cell through the shaver's onboard charging circuit and confirmed the BMS accepted the charge without faulting. Motor load during the cutting cycle stayed within the cell's discharge curve.
• Port drying before charge: These shavers are often rinsed under water. Before reconnecting to the charger, dry the charging contacts completely. Moisture bridging the contacts causes a BMS protection trip the device reports as a dead battery — not a charging error.

Capacity fade from daily partial charging on the QC5055

Ni-MH cells develop a voltage memory effect when repeatedly charged from a shallow state of discharge. The QC5055's fuel indicator recalibrates against recent charge cycles, so it drifts — showing full when the cell is only partially charged. Over time, the shaver cuts out earlier and earlier even after a full-charge cycle. Letting the cell discharge fully before recharging at least once every few weeks slows this drift significantly.

Shaver motor speed dropping before the indicator shows empty

Ni-MH cells at end of life show a steep voltage sag under motor load before the BMS hits its cutoff threshold. The shaver's indicator reads remaining charge at rest, not under load — so the display can show two bars while the motor is already starved for voltage. The cutting head slows, drags on longer hair, and may stall completely before the low-battery indicator triggers. If this is happening with the original cell, a fresh 700mAh cell at the correct 1.2V will eliminate the sag.