Avaya SK37H1-D Cordless Phone Replacement Battery 3.6V 1100mAh

Avaya 3626 / BPX100 Series — 3.6V Ni-MH Replacement Battery (SK37H1-D)

This is a 3.6V, 1100mAh Ni-MH battery for the Avaya 3626, 3636, 3216, and BPX100 cordless handsets. It replaces OEM part SK37H1-D and restores full wireless operation to handsets that have lost charge capacity over time. Physical dimensions are 58.12 × 45.30 × 15.60mm — confirm these against your current pack before ordering.

• 3626 / BPX100 platform fit: These models share the same 3.6V single-cell NiMH format, connector orientation, and base-station charge circuit. One pack covers all listed handsets without modification.
• Bench tested on actual hardware: We cycled this pack through the Avaya base station charge circuit. The charge acceptance voltage landed within spec and the base showed a normal charge indicator — no error state triggered on the units we ran.
• First-charge protocol for NiMH cordless packs: After installing, seat the handset in the base and leave it for a full 16 hours before first use. NiMH cells in cordless phones need a slow initial charge to reach rated capacity — skipping this step is the most common cause of shortened talk time complaints on fresh replacements.

Talk time shorter than the original battery after replacement

NiMH cells ship in a partially discharged, low-activity state. Until the cells complete three to five full charge-discharge cycles, usable capacity sits well below the rated 1100mAh. The base station's trickle-charge circuit is part of this conditioning process — it cannot be rushed with a fast external charger. After five normal cycles through the Avaya base, talk time should reach the rated figure.

Base station showing a charge error or no-charge light on a new pack

NiMH batteries that have sat in storage can drop below the voltage threshold the Avaya base uses to confirm a valid pack is present. If the base shows an error light or simply does not begin charging, the pack voltage is likely too low for the charge circuit to accept. Remove the handset, wait 30 seconds, and reseat it firmly — this resets the charge detection cycle. If the error persists after two reseating attempts, use a compatible external NiMH charger to raise the pack voltage above 3.0V, then return it to the base.