Nortel T7406 NTAB9682 Replacement Battery 3.6V 2000mAh

Nortel T7406 — 3.6V Ni-MH Replacement Battery (NTAB9682)

This is a 3.6V, 2000mAh Ni-MH battery for the Nortel T7406 cordless phone handset. It replaces OEM part numbers NTAB9682, M7001, and A0845917. Fits directly into the T7406 handset and restores full wireless operation from the base station.

• T7406 handset fit: The T7406 uses a 3.6V Ni-MH pack with a specific contact layout and physical envelope. This battery matches that footprint, voltage rail, and charge acceptance curve so the base station charges it the same way it charged the original.
• Bench tested on actual hardware: We cycled this pack on a T7406 base station and confirmed the charging circuit accepted the battery without error. The BMS held charge termination correctly at end-of-charge, and voltage recovery after load matched rated capacity across three full 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 first use. Ni-MH cells in cordless phones ship in a partial state and need a slow, uninterrupted charge to reach rated capacity — skipping this shortens usable talk time from the start.

Why the T7406 base station shows no charge light on a new Ni-MH pack

Ni-MH batteries lose voltage during storage. If the pack drops below the T7406 base station's charge acceptance threshold — typically under 3.0V — the base may show no charge indicator or display an error light. This is not a faulty battery. The fix is to leave the handset seated in the base undisturbed for up to 30 minutes; the trickle charge stage will bring cell voltage up until the base recognises the pack and switches to full charge mode. Once the charge light appears, allow the full 16-hour first charge to complete.

Talk time shorter than the original battery after replacement

Ni-MH cordless phone batteries do not deliver full rated capacity in the first one or two cycles — this is normal cell chemistry behaviour, not a defect. Capacity builds across the first three to five full charge and discharge cycles as the cell plates form properly. Run the handset until it signals low battery, then return it to the base for a full charge each time. By cycle five, talk time should reach the rated 2000mAh level.