Beurer BY 110 Replacement Battery NV604464 3.7V 1400mAh

Beurer BY 110 / JBY 100 — 3.7V Li-ion Replacement Battery (NV604464)

This is a 3.7V, 1400mAh Li-ion battery (NV604464) for the Beurer BY 110, JBY 100, and 952.10 baby phone parent units. It slots into the parent unit handset — the portable receiver parents carry around the house. Capacity is rated at 5.18Wh, matching the original spec.

• BY 110, JBY 100, and 952.10 parent units: These three models share the same parent unit housing, the same 3.7V single-cell Li-ion architecture, and the same NV604464 cell format. The BMS on each unit expects the same charge termination voltage, so one battery covers all three.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the BY 110 parent unit. The BMS accepted the cell without fault flags, charge termination triggered correctly at 4.2V, and the low-battery alert fired at the expected threshold.
• Re-pair after power interruption: When the parent unit loses power completely during a battery swap, the BY 110 drops its wireless link to the transmitter unit. After fitting the new battery, hold the pairing button on both units until the connection LED confirms a successful link.

Parent unit battery draining overnight on the BY 110

The BY 110 parent unit keeps the screen active during night-time monitoring, and the radio receiver runs continuously — that combination draws sustained current for six to eight hours straight. A degraded original cell handles this badly; voltage sags early and the BMS shuts down the unit before morning. A fresh 1400mAh cell restores the capacity headroom needed for overnight operation. Enable the screen timeout in the BY 110 menu to reduce draw during quiet periods.

Range dropping after a battery swap on the BY 110

The BY 110 parent unit's radio transmit power is voltage-sensitive. If the new battery is fitted and used immediately without a full charge, the cell starts near mid-state-of-charge and the radio operates below its rated output. This cuts effective range noticeably — walls and floors that the unit normally penetrates start blocking the signal. Charge the parent unit to 4.2V (full charge indicator lit) before the first use after fitting a replacement cell.