Nortel NTTQ5010 Replacement Battery 3.6V 1100mAh

Nortel NTTQ5010 / WLAN 2211 — 3.6V Ni-MH Replacement Battery (SK37H1-D)

This is a 3.6V, 1100mAh Ni-MH battery for the Nortel NTTQ5010, NTTQ5050, WLAN 2211, and 2211 cordless handsets. It replaces OEM part numbers SK37H1-D and HBPX100-M. When the original pack stops holding charge, this swap restores the handset to full operation on the same base station.

• NTTQ5010, NTTQ5050, and WLAN 2211 compatibility: All four models share the same 3.6V three-cell NiMH pack format, identical connector pinout, and the same base station charging circuit. One battery part number covers the entire group.
• Bench tested on actual hardware: We cycled this pack through the NTTQ5010 charging circuit and confirmed the base station accepted charge without flagging an error. The NiMH cells responded normally to the trickle-charge termination signal from the base.
• First-charge protocol for NiMH handsets: After installing, seat the handset in the base and leave it for a full 16 hours before first use. NiMH cells ship partially discharged. A slow initial charge lets each cell reach balanced capacity — skipping this step will leave you with noticeably shorter talk sessions for the first several cycles.

Base station showing no-charge light on a fresh NiMH pack

NiMH batteries lose voltage during storage. If the pack sits long enough, its resting voltage can drop below the threshold the NTTQ base station needs to recognise a valid battery and begin charging. The base interprets this as a fault rather than a discharged cell. Placing the handset in the base for 30 minutes and then removing and reseating it often clears the stall — the brief contact lets the circuit sample voltage again. If the light stays off, check that the handset contacts are clean and making firm contact with the base cradle pins.

Range drops mid-call after fitting a new battery

DECT handsets draw a surge of current each time the RF module transmits. If the NiMH cells have not been through at least three full charge-discharge cycles, internal resistance is still elevated and voltage sags under that transmit load. The handset's RF output drops as a result, and range shrinks noticeably compared to a conditioned pack. Run three full cycles — full charge in base, talk until the low-battery warning sounds, then return to base — and check whether range recovers. A conditioned pack at full charge should measure 4.2–4.3V across the terminals before installation.