Babytime BT-2S Replacement Battery 3.7V 3000mAh Li-Polymer

Babytime BT-2S — 3.7V Li-Polymer Replacement Battery (BAT-B2S)

This is a 3.7V 3000mAh Li-Polymer replacement battery for the Babytime BT-2S baby phone monitor. It fits the parent unit of the BT-2S system and restores wireless, portable operation when the original cell no longer holds a charge. Capacity is 11.1Wh, matching the OEM BAT-B2S specification.

• BT-2S parent unit fit: The BT-2S parent unit uses a single-cell Li-Polymer pack at 3.7V nominal. The BAT-B2S format — 64.00 × 49.80 × 6.50mm — matches the internal cavity and connector pinout directly. No modification needed.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the BT-2S platform. The onboard BMS handled charge termination cleanly at 4.2V and held low-voltage cutoff without nuisance trips during normal monitor operation.
• Re-pair after fitting: The BT-2S parent unit loses its wireless link to the camera unit when power is fully interrupted. After fitting this battery, hold the pairing button on both units until the connection indicator confirms a live link before placing the camera unit in the nursery.

Parent unit range reduced after battery swap on the BT-2S

The BT-2S radio module draws more current when transmitting at full range. If the replacement cell is not fully charged at first use, the voltage sags under that load and the radio steps down its output power. The result is a noticeably shorter range than expected — even though the unit appears to be working normally. Charge the parent unit to 4.2V before the first use to get the full rated transmission range.

Parent unit battery draining overnight with screen active

Running the BT-2S parent unit display on continuously through the night is a sustained draw on a 3000mAh cell. The backlit screen adds a constant load on top of the audio and radio circuits, which depletes the battery faster than most users expect. The BT-2S includes a screen timeout setting — activate it so the display sleeps while audio monitoring continues. This significantly extends the time between charges during overnight use.