Philips Avent SCD833 Replacement Battery 3.7V 3400mAh

Philips Avent SCD833 / SCD835 — 3.7V Li-ion Replacement Battery (NTA3459-4)

This 3.7V, 3400mAh Li-ion battery replaces the original cell in the parent unit of the Philips Avent SCD833 and SCD835 digital audio baby monitors. It fits the SCD833, SCD833/26, SCD835, and SCD835/26 variants, along with additional compatible models in the Avent monitor range. When the original battery loses capacity or stops holding charge, this replacement restores the parent unit to normal operation.

• SCD833 and SCD835 parent unit compatibility: Both model lines share the same parent unit housing, battery bay dimensions, and connector pinout. The BMS in each unit reads the same charge profile, so the NTA3459-4 cell works across all listed variants without modification.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the SCD833 parent unit. The onboard BMS accepted the cell without fault codes, balanced correctly at top-of-charge, and held the voltage rail stable across both audio transmission and screen-on states.
• Re-pairing after battery swap: The SCD833 parent unit loses its wireless link to the camera unit when power drops completely during a battery change. After fitting the new cell, follow the pairing sequence in the manual — press and hold the link button on the camera unit until the parent unit confirms connection.

Parent unit battery draining overnight on the SCD833

The SCD833 parent unit runs the screen, speaker circuit, and 2.4GHz radio simultaneously during night-time monitoring. With the screen left on continuously, the draw is sustained — not intermittent. If the screen timeout is disabled or set too long, the battery depletes well before morning. Enable the screen timeout in the display settings so the screen dims when no alert is active, and the radio circuit continues operating in the background at lower current draw.

Night vision not working after fitting a new battery

The camera unit's IR LEDs require a stable voltage supply to activate night vision mode. If the parent unit battery is installed but not yet charged, the system can initialise before the cell reaches its operating voltage threshold. Night vision may appear missing or inactive until the parent unit battery reads at least 3.6V. Charge the parent unit fully before the first overnight use and confirm night vision activates during the pairing check.