Sony BP-T50 2.4V Cordless Phone Compatible Battery 1200mAh

Sony SPP-N1000 Series — 2.4V Ni-MH Replacement Battery (BP-T50)

This is a 2.4V 1200mAh Ni-MH replacement battery for the Sony SPP-N1000 cordless telephone handset. It fits the SPP-N1000, SPP-N1001, SPP-N1003, and SPP-N1004 models. When the original BP-T50 pack loses capacity or stops holding a charge, this replacement restores the handset to full operation.

• SPP-N1000 series compatibility: The N1000, N1001, N1003, and N1004 all use the same 2.4V two-cell NiMH pack with an identical connector and form factor. The base station's charge circuit is calibrated for this voltage range, so the replacement works with the existing charging dock without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the SPP-N1000 platform. The BMS accepted charge from the base station on the first placement, and voltage held steady through standby load at 2.4V nominal.
• First-charge protocol for NiMH cordless packs: Place the handset in the base for a full 16 hours before first use. NiMH cells in cordless phones are shipped in a partially discharged state — a slow initial charge lets each cell reach full capacity and sets the baseline for all subsequent cycles.

Talk time shorter than the original battery after replacement

New NiMH cells often deliver noticeably less capacity in the first few uses — this is normal cell behaviour, not a fault. NiMH chemistry requires three to five full charge-discharge cycles before the cells reach their rated 1200mAh. Each cycle slightly increases capacity as the electrolyte distributes evenly across the cell plates. Run the handset until the low-battery indicator activates, then return it to the base for a full charge — repeat this three to five times.

Base station not registering a charge on the new pack

NiMH packs discharged during storage can drop below the voltage threshold the base station uses to detect a battery. If the charge indicator light stays off or flashes an error, the pack voltage is too low for the base to accept. Remove the handset, leave the battery in at room temperature for 15 minutes, then reseat it firmly in the base — contact must be clean and flush. If the base still shows no charge, check that the handset contacts and base cradle contacts are free of oxidation, then wipe both with a dry cloth before reseating.