GP80AAALH3BMX Cordless Phone Replacement Battery 3.6V 800mAh

GP GP80AAALH3BMX — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 800mAh Ni-MH replacement battery for GP cordless phone handsets using the GP80AAALH3BMX pack. It fits the wireless handset directly, restoring power to units where the original cell has degraded or failed to hold charge. Voltage and form factor match the original specification at 50.86 x 31.42 x 10.52mm.

• GP80AAALH3BMX handset fit: These cordless handsets run a 3.6V three-cell AAA Ni-MH configuration. The connector pinout and physical tray dimensions align with the original pack, so the battery seats without modification.
• Bench tested on actual hardware: We ran charge cycles through a DECT handset base unit and confirmed the BMS accepted charge without triggering fault states. The cells reached stable voltage after three full conditioning cycles.
• First-charge protocol for Ni-MH handsets: After installing, place the handset in the base for a full 16 hours before the first call. Ni-MH cells in cordless phones are shipped partially discharged — a slow initial charge through the base circuit lets the cells reach rated capacity rather than a surface charge plateau.

Base station showing charging error after installing a new Ni-MH pack

DECT base stations use a delta-V detection circuit to confirm charging. A new Ni-MH battery stored for several months can arrive at a resting voltage low enough that the base reads it as a fault rather than a dischargeable cell. This does not mean the battery is defective. Place the handset in the base, leave it undisturbed for at least two hours, and the voltage will rise enough for the base to recognise the pack and switch to normal charge mode.

Range drops noticeably when the handset moves away from the base

RF transmit power in DECT handsets draws short bursts of current from the battery. When a Ni-MH cell is not yet conditioned, its internal resistance is higher, causing voltage to sag under that RF load. The handset firmware interprets the sag as a low-battery state and reduces transmit power to protect the cell. Run three full charge-and-use cycles through the base, and internal resistance will fall — target a resting voltage of 3.6V before each cycle begins.