Moonybaby MB55931 Baby Monitor Replacement Battery 3.7V 1100mAh

Moonybaby MB55931 Series — 3.7V Li-Polymer Replacement Battery (1ICP5/36/53-1SPT)

This 3.7V 1100mAh Li-Polymer battery replaces the original power cell in the Moonybaby MB55931 parent unit. It fits the MB55931, MB55931-2T, Trust 30, Split 55, and several additional models that share the same OEM part number 1ICP5/36/53-1SPT. When the factory battery degrades and stops holding charge, this is the direct cell replacement.

• MB55931 and Trust 30 platform compatibility: These models share the same parent-unit board layout, connector pinout, and BMS handshake voltage. Swapping cells between them works because the protection circuit communicates at the same 3.7V nominal rail across the entire platform.
• Bench tested on actual hardware: We ran this cell through full charge-discharge cycles on the MB55931 parent unit. The BMS accepted the cell without fault flags, and the unit powered on cleanly from flat through to full charge cutoff at 4.2V.
• Post-swap wireless re-pair: The MB55931 parent unit drops its camera link when it loses power completely. After fitting this battery, hold the pair button on both units until the parent unit confirms the connection — the camera feed will not appear until this step is done.

Parent unit not connecting to the camera unit after battery swap

The MB55931 stores its camera pairing data in volatile memory backed by the battery. A full power loss — which happens during a battery swap — wipes that link. The parent unit boots up without any stored camera address and waits for a new pairing handshake. Press and hold the pair button on the camera unit first, then trigger pairing on the parent unit and wait for the confirmation tone before releasing either button.

Battery draining overnight with the parent unit screen on

Running the parent unit display continuously through the night is a sustained draw the 1100mAh cell was not sized to sustain indefinitely. The backlit LCD and active radio receiver together pull enough current that the cell can hit the BMS low-voltage cutoff before morning. Enable the screen timeout function in the parent unit menu — the audio channel stays live while the screen sleeps, dropping the draw significantly and extending charge capacity across the night.