Phone Mate 1120 Replacement Battery 4.8V 2000mAh

Phone Mate 1120 / 1121 / 1140 — 4.8V Ni-MH Replacement Battery

This is a 4.8V, 2000mAh Ni-MH replacement battery for the Phone Mate 1120, 1121, and 1140 baby monitor parent units. When the original cell stops holding a charge, the parent unit loses its ability to operate untethered from the wall. This battery restores cordless operation to the handset.

• 1120, 1121, and 1140 compatibility: These three models share the same 4.8V battery format, connector orientation, and cell count. The parent unit housing and charging circuit are common across the range, so one battery cell pack covers all three.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the 1120 parent unit. The BMS accepted the charge without flagging errors, and the unit held stable voltage across the full draw cycle — including the IR LED load during night vision mode.
• Re-pair the parent unit after fitting: Baby monitors on this platform drop their wireless link to the camera unit when the parent unit loses power completely. After fitting the new battery, power the camera unit first, then power on the parent unit and run the pairing sequence from the handset menu before relying on it overnight.

Parent unit draining overnight with screen on

Running the 1120 parent unit through the night with the screen active is a sustained high-draw condition. The LCD backlight and audio circuit together pull significantly more current than standby-only operation. A fresh Ni-MH cell handles this, but an aged or partially charged cell will sag below the minimum operating voltage before morning. Enable the screen timeout in the handset menu so the display cuts out between alerts — this extends usable charge per cycle without any other changes.

Night vision not working after battery replacement

The IR LEDs on the camera unit draw a spike of current when night vision activates, and the parent unit's radio circuit also runs at full power during this handshake. If the replacement battery has not had a complete initial charge, the cell voltage can sag just enough to cause the IR circuit to drop out or flicker. This shows up as a dark screen or intermittent black-and-white image shortly after pairing. Charge the parent unit fully — to 4.8V across the pack — before the first overnight use.