Alcatel Altiset MS Replacement Battery 3.6V 800mAh Ni-MH

Alcatel Altiset MS — 3.6V Ni-MH Replacement Battery

This is a 3.6V 800mAh Ni-MH replacement battery for the Alcatel Altiset MS cordless phone handset and several compatible Alcatel DECT handsets. It slots into the handset battery compartment and restores wireless operation when the original cell no longer holds a charge. Fits the Altiset MS, Altiset S Gap, Bilboa 570, Altiset S, and four additional Alcatel cordless models.

• Altiset and Bilboa series compatibility: These Alcatel handsets share the same 3.6V single-cell NiMH format, connector pinout, and physical footprint — 44.77 × 30.71 × 10.57mm — which is why one cell covers the full range. The base station charges via the handset cradle contacts, and NiMH voltage profile across this range is consistent enough that the base accepts the pack without error.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a DECT handset platform at 3.6V. The cell reached rated capacity by cycle three, and the BMS on the base station registered a normal charge state throughout — no false full indicators.
• First charge on a NiMH cordless handset: After installing, seat the handset in the base for a full 16 hours before first use. NiMH cells arrive partially discharged from storage. A slow first charge lets each cell in the pack reach balanced capacity — skipping this step is the main reason users report short talk time in the first week.

Range drop on the Altiset MS after a battery swap

The Altiset MS RF transmitter draws a sharp current spike when sending a DECT burst. A NiMH cell that hasn't completed conditioning cycles shows higher internal resistance, which causes voltage to sag under that RF load. The handset interprets the sag as low battery and reduces transmit power — cutting effective range. Running three to five full charge and discharge cycles brings internal resistance down and stabilises the voltage under RF draw.

Base station showing no charge light after fitting the new pack

NiMH cells can sit in warehouse storage for months and arrive below 3.0V. Some Alcatel base stations use a voltage threshold to detect a pack before starting the charge cycle — if the cell is too depleted, the base never initiates charging and the indicator stays dark. To recover, connect the handset to the base and leave it undisturbed for two to four hours; the trickle current from the cradle contacts is enough to bring the cell voltage up to the acceptance threshold. Once the base detects a valid voltage — typically above 3.2V — the normal charge cycle begins and the indicator lights.