Arlo Wired Video Doorbell Compatible Battery 3.7V 400mAh

My Arlo doorbell stops recording mid-clip — the video just cuts off partway through a motion event. What's causing that?

A mid-clip dropout on the Arlo Wired Doorbell usually traces back to a WiFi reconnect current spike. When the wireless signal wavers, the radio draws a burst of current to re-establish the connection — that spike can exceed the backup cell's BMS discharge threshold and trigger a cutoff. Check your router signal strength at the doorbell location and confirm it stays above -65 dBm. If signal is solid, the backup cell may have degraded below its rated capacity and can no longer absorb the spike — replacing the cell resolves it.

The doorbell rings and shows live view fine, but motion detection has stopped triggering recordings entirely after I swapped the battery. What happened?

Motion trigger dropout after a cell swap is almost always a firmware registration issue, not a hardware fault. The IR LED array and processor together draw a combined current spike when motion is detected — if the firmware hasn't logged the new cell correctly, the BMS interprets that spike as an overload and suppresses the trigger. Power cycle the doorbell once through the Arlo app settings, then walk in front of the doorbell to force a manual motion event. If recordings still don't appear in the library, remove the device from the app and re-add it to force a full firmware re-registration.

The doorbell's backup battery drains to empty within a day or two even when mains power is connected. Is the charging circuit broken?

Continuous deep discharge like this usually means the cell's resting voltage has dropped below the BMS re-entry threshold — typically around 2.5V for this chemistry — and the charging circuit can't initiate a charge cycle. The doorbell's charger wonves not apply current to a cell it reads as potentially damaged. Confirm mains wiring is delivering correct voltage at the doorbell terminals first. If wiring checks out, replace the cell — once a Li-Polymer cell drops below 2.5V repeatedly, internal resistance climbs and it will not recover capacity through normal charging.