AudioVox BT911 Replacement Battery 3.6V 2000mAh Ni-MH

AudioVox BT911 Cordless Phone — 3.6V Ni-MH Replacement Battery (BT911)

This is a 3.6V 2000mAh Ni-MH replacement battery for the AudioVox BT911 cordless telephone handset. It also fits the DST961, DT911, and DT921C models. The pack slots into the handset and restores talk time and standby operation once the original battery has degraded.

• BT911 and DT-series handset fit: These models share the same 3.6V three-cell NiMH pack format, connector pinout, and physical housing dimensions — 53.67 x 45.98 x 15.64mm. One battery fits across the range because AudioVox standardised the power bay on this cordless platform.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a BT911 handset. The base station accepted the battery without error, the charge indicator lit correctly, and the BMS held within expected voltage boundaries across all cycles.
• First charge on NiMH cordless packs: After installing, seat the handset in the base and leave it for a full 16 hours before the first use. NiMH cells in cordless phones require a slow initial charge to reach rated capacity — pulling the handset off after a short charge on day one will set a lower capacity ceiling for subsequent cycles.

Base station charge light not activating on a fresh NiMH pack

NiMH batteries sit in storage before sale, and cell voltage can drop below the threshold the base station uses to confirm a valid pack is seated. When resting voltage is too low, the base treats the pack as absent or faulty and withholds charge current. Place the handset in the base and leave it undisturbed — most AudioVox bases will begin a trickle charge within 30 minutes once the pack voltage climbs above roughly 3.0V. If the light still does not activate after an hour, reseat the handset firmly to ensure the charging contacts are clean and fully engaged.

Range drops noticeably when the handset moves away from the base

On DECT cordless phones, the handset radio draws a short burst of higher current each time it transmits. If the NiMH pack's internal resistance is elevated — common in aged cells or in a new pack before conditioning — voltage sags under that RF load. The handset interprets the sag as low battery and reduces transmit power, which shrinks effective range before the battery actually reads empty. Running three to five full charge and discharge cycles brings internal resistance down and stabilises voltage under transmit load. After conditioning, range should return to the original operating distance.