V Tech VM901 Baby Monitor Replacement Battery 3.8V 2100mAh

V Tech VM901 / VM350 Series — 3.8V Li-ion Replacement Battery

This 3.8V, 2100mAh Li-ion battery replaces the internal cell in the parent unit of the V Tech VM901, VM350, and VM350-2 baby monitors. It restores portability to the parent unit when the original cell can no longer hold a charge. Dimensions are 63.00 × 50.40 × 5.40mm — confirm these against your existing cell before fitting.

• VM901 and VM350 series compatibility: These models share the same parent unit form factor, battery bay dimensions, and 3.8V supply rail. The connector pinout is identical across the range, so one cell fits all three variants without modification.
• Bench tested on actual hardware: We cycled this cell through the VM901 parent unit and confirmed the BMS accepted charge without fault flags, stepped down correctly at low-voltage cutoff, and resumed cleanly from a full discharge state.
• Wireless re-pair after installation: The VM901 parent unit drops its camera link whenever the battery is fully removed. After fitting this cell and powering on, run the manual re-pair sequence from the parent unit menu before expecting live video — the monitor does not reconnect automatically.

Parent unit not connecting to camera unit after battery swap

Removing the battery cuts all power to the parent unit's wireless module, which clears its stored camera pairing data on many VM-series monitors. When you power back on, the unit boots without a linked camera and shows a "searching" or blank screen. This is not a fault with the new battery — it is a normal consequence of a full power interruption. Navigate to the parent unit's camera menu, select "Add Camera" or "Pair Camera," and follow the on-screen steps to re-establish the link.

Reduced transmission range straight after fitting the new battery

The VM901's 2.4GHz radio draws more current at longer range, and a partially charged cell causes voltage sag that the radio module interprets as a low-power condition — it steps down transmission strength as a result. This shows up as dropouts or a noticeably shorter usable range right after a battery swap. The fix is straightforward: charge the parent unit to 100% before moving it away from the base. A full charge brings the cell to 4.35V and gives the radio module its full voltage headroom.