Panafone KX-T9980 Cordless Phone Replacement Battery 3.6V 300mAh

Panafone KX-T9980 — 3.6V Ni-MH Replacement Battery

This is a 3.6V 300mAh Ni-MH battery for the Panafone KX-T9980 cordless handset. It replaces the original cell pack that powers the handset away from the base station. When the original degrades and can no longer hold a charge, this swap restores normal operation.

• KX-T9980 handset fit: The KX-T9980 runs a single-cell Ni-MH pack at 3.6V nominal. This battery matches that voltage rail and the physical dimensions of the original pack — 31.00 × 30.41 × 10.64mm — so it seats correctly in the handset compartment without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a Ni-MH-compatible charger and confirmed the BMS accepts full charge without triggering a fault state. Cell voltage held stable across five conditioning cycles.
• First-charge protocol for Ni-MH cordless packs: After installing, seat the handset in the base and leave it for a full 16 hours before the first call. Ni-MH cells at storage charge have not been through a slow conditioning charge — skipping this step leaves rated capacity on the table for the first several cycles.

Talk time shorter than original battery after replacement

New Ni-MH cells ship at partial storage charge, not full rated capacity. The first three to five charge and discharge cycles are conditioning cycles — each one lets the cell reach a slightly higher capacity than the last. Skipping the 16-hour initial charge and running shallow cycles keeps the pack below its 300mAh rating. Run three full charges in the base followed by use until the handset signals low battery, and talk time will reach its rated level.

Base station shows no charge light after battery swap

Cordless phone bases use a voltage threshold to detect whether a handset is seated and ready to charge. A Ni-MH pack that has sat in storage can drop below that detection threshold — typically around 3.0V — causing the base to show no charge indicator or an error light. Remove the battery, connect it briefly to a stand-alone Ni-MH charger to bring the cell voltage above 3.2V, then reseat the handset in the base. The base should recognise the pack and begin a normal charge cycle.