Arlo Baby A-3 Replacement Battery 3.7V 2200mAh

Arlo Baby / ABA1100 — 3.7V Li-ion Replacement Battery (A-3, 308-10033-01)

This is a 3.7V, 2200mAh Li-ion replacement battery for the Arlo Baby indoor security camera (Model Baby, ABA1100). It matches the OEM cell dimensions of 42.40 × 34.30 × 17.50mm and uses the same voltage rail the camera's firmware expects. Swap it in when the original cell no longer holds charge through a full monitoring cycle.

• Baby and ABA1100 fit: Both model numbers share the same internal battery bay, connector pinout, and 3.7V BMS handshake. Either model accepts this cell without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Arlo Baby platform. The BMS accepted the cell cleanly, balancing held across cycles, and the protection circuit tripped at the expected low-voltage cutoff without false trips during IR LED pulses.
• First-install power cycle: After fitting the new battery, power cycle the camera once through the Arlo app. The firmware must register the new cell before motion events log correctly to cloud storage — skipping this step can cause missed clips even when the camera appears online.

Why the Arlo Baby goes offline in the app after a battery swap

The Arlo Baby holds a session token in RAM that ties the camera to the cloud backend. Removing the battery clears that token. When the new cell goes in, the camera reboots and attempts to reconnect, but the app sometimes fails to re-establish the link automatically. If the camera shows offline after swap, open the Arlo app, go to Device Settings, and tap Restart Device. This forces a fresh token handshake without a full re-pair.

App showing 0% or stuck percentage after installing a new battery

The Arlo Baby uses a voltage-threshold indicator, not a fuel-gauge IC — the camera reads cell voltage at intervals and maps it to percentage bands. A brand-new cell sitting at a slightly different resting voltage than the depleted original can land outside the expected band, so the app displays 0% or a stale figure. Run one full charge to 100% via the Arlo charging cable, then let the camera draw the cell down through normal use. After that single cycle the voltage thresholds recalibrate and the percentage reads accurately. Target a resting voltage of approximately 4.1–4.2V post-charge to confirm the cell seated correctly.