GP 30AAH3BMX Cordless Phone Replacement Battery 3.6V 1500mAh

GP 30AAH3BMX / 30AAK3BMX — 3.6V Ni-MH Replacement Battery for Cordless Phones

This is a 3.6V, 1500mAh Ni-MH replacement battery pack carrying GP OEM part numbers 30AAH3BMX and 30AAK3BMX. It fits cordless DECT handsets that use this standardised triple-cell AAA Ni-MH format. At 50 × 42 × 14mm, the physical footprint matches the original pack directly.

• Why these two part numbers share one pack: 30AAH3BMX and 30AAK3BMX refer to the same three-cell AAA Ni-MH configuration at 3.6V. The suffix change reflects a production revision, not a chemistry or connector difference. Both draw from the same voltage rail and use the same physical connector housing.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on DECT handset hardware. The BMS accepted charge from a standard base station cradle without tripping an error state. Cell balance across all three AAA cells remained within 20mV after five full cycles.
• First charge on a DECT handset: After installing, seat the handset in the base and leave it for a full 16 hours before first use. Ni-MH cordless phone packs arrive partially discharged from storage. A slow first charge lets all three cells reach rated capacity together — skipping this shortens the pack's usable life.

Base station showing a charging error on a new Ni-MH pack

Some DECT base stations use delta-V detection to confirm a battery is charging. A pack that has self-discharged below roughly 3.0V during storage can confuse this circuit — the base sees a flat voltage curve and flags an error instead of entering charge mode. The fix is a short pre-charge: place the handset in the base, wait 10 minutes, remove it, then reseat it firmly. This brief contact often pushes enough current into the cells to lift voltage above the base station's acceptance threshold and allow normal charging to resume.

Range drops noticeably after fitting the replacement pack

Reduced range after a battery swap usually points to voltage sag under RF transmit load, not a faulty pack. A freshly installed Ni-MH battery that has not completed its first conditioning cycle will sag further under the burst current drawn during DECT transmission. The handset's RF output power is tied to supply voltage — when voltage dips, transmit power drops with it, shrinking effective range. Run three to five full charge and discharge cycles on the handset before judging range; cell capacity and voltage stability both improve across those cycles.