Uniden UBW2101C Compatible Battery 3.7V 1250mAh YK843553

Uniden UBW2101C Camera / UBWC21 — 3.7V Li-Polymer Replacement Battery (YK843553)

This is a 3.7V, 1250mAh lithium-polymer replacement battery for the Uniden UBW2101C Camera and UBWC21 parent unit. It replaces OEM part YK843553 and restores power to the parent unit in Uniden's wireless baby monitoring system. Dimensions are 52.40 × 34.00 × 7.10mm — measure your original cell before ordering if you're unsure.

• UBW2101C and UBWC21 parent unit fit: Both models share the same 3.7V single-cell Li-Polymer pack and YK843553 part number. The connector pinout and BMS handshake are identical across this monitor series, so one cell covers both units.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the parent unit. The BMS handled charge termination cleanly at 4.2V and held low-voltage cutoff without tripping prematurely during screen-on operation.
• Wireless re-pair after swap: Baby monitor parent units lose their stored camera link when power drops to zero during a battery swap. After fitting the new cell, power on the parent unit and follow the re-pair sequence in your UBW2101C manual — typically holding the pair button on the camera unit for three seconds.

Parent unit battery draining overnight with screen active

The UBW2101C parent unit runs the LCD backlight, radio receiver, and speaker circuit simultaneously during monitoring — that is a sustained draw well above standby levels. A 1250mAh cell at this draw rate will not last indefinitely without a charge top-up. Enable the screen timeout or VOX mode in the parent unit settings so the display shuts off between sound events. This one change significantly reduces overnight drain without interrupting audio monitoring.

Night vision drops out or appears dim after fitting a new battery

The IR LEDs on the camera unit draw from the camera's own power source, but the parent unit's display of that IR feed is voltage-sensitive — a partially charged parent unit battery can cause the screen to dim or the IR image to appear degraded. This is not a camera fault. Charge the parent unit fully to 4.2V before your first night-time session. If the IR image remains poor after a full charge, check that the night vision mode is enabled in the parent unit menu rather than set to auto.