Philips SBC 468/91 Replacement Battery 4.8V 700mAh

Philips SBC 468/91 Series — 4.8V Ni-MH Replacement Battery (SBC-EB4880)

This is a 4.8V 700mAh Ni-MH battery for the Philips SBC 468/91 and SBC 486/91 baby monitor parent units, along with the SBC-SC364 and compatible models. It replaces OEM part SBC-EB4880. The parent unit is the handheld receiver parents carry while the nursery transmitter stays fixed — this battery keeps that unit cordless.

• SBC 468/91 and 486/91 parent unit compatibility: These models share the same 4.8V four-cell NiMH pack format, connector pinout, and charge circuit. Swapping between them requires no modification — voltage rail and physical footprint match across the range.
• Bench tested on actual hardware: We cycled this pack through the SBC 486/91 charge circuit. The NiMH charge termination responded correctly to delta-V detection, and the cells balanced across all four without heat anomalies at the connector.
• Post-swap wireless re-pair: When the parent unit loses power completely — as it does during a battery swap — it drops its wireless link to the nursery transmitter. After fitting this battery, charge it first, then re-pair the two units using the pairing button on the transmitter base before putting the monitor back into service.

Parent unit not connecting to nursery transmitter after battery swap

The SBC 468/91 parent unit stores its pairing data in volatile memory backed by the battery. A full power loss — which happens every time the battery is removed — wipes that link. The transmitter base still has its side of the pairing stored, but the parent unit comes back blank. To restore the connection, hold the pairing button on the transmitter base until the parent unit registers the signal. Do this with the battery at or above 4.0V — a low charge state can cause the radio to under-power during pairing and fail to latch.

Range noticeably shorter than before the battery was replaced

The 2.4GHz radio in the parent unit draws higher current during transmission bursts, and NiMH cells show voltage sag under that load when not fully charged. A battery at 50% charge may read a stable resting voltage but sag below the radio's minimum operating threshold the moment it transmits. The result is a reduced effective range or intermittent dropout that looks like a hardware fault. Charge the pack to full — 4.8V resting after a complete charge cycle — before testing range, and the issue typically resolves without any other intervention.