Alcatel Versatis Slim 300 Compatible Battery 3.7V 500mAh

Alcatel Versatis Slim 300 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 500mAh Li-ion replacement battery for the Alcatel Versatis Slim 300 cordless DECT phone. It fits the Versatis Slim 300, Versatis Slim 300GE, and variants including 28115FE1, 28115FE1-A, and 28106FE1. The battery slots into the handset's rear compartment and restores wireless operation away from the charging base.

• Versatis Slim 300 series compatibility: These handset variants share the same 3.7V Li-ion cell format, connector orientation, and physical footprint — 43 x 28 x 4mm. One battery fits across the range without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Versatis Slim 300 base station. The BMS accepted charge without fault flags, and the handset showed full signal bars throughout the discharge test.
• First charge after fitting: Place the handset in the base immediately after installing this battery and leave it for a full 16 hours before use. Li-ion cells discharged during storage need a slow initial charge to reach rated capacity at 500mAh.

Why the Versatis Slim 300 loses range after a battery swap

The Versatis Slim 300 DECT radio module draws extra current during transmission bursts. If the replacement battery's state of charge is low from storage, its internal voltage sags under that RF load. The handset compensates by reducing transmit power, which cuts effective range. A full charge cycle before first use brings the cell to 3.7V nominal and eliminates the sag.

Handset not pairing with the base after battery removal

Removing the battery completely clears the handset's volatile memory, which can drop the DECT pairing link stored on the unit. The base station may show a missing handset indicator or refuse calls. To re-register, hold the handset's paging or find button while placing it in the base — the exact sequence is on page 12 of the Versatis Slim 300 user guide. Once paired, the handset should show line status within 30 seconds.