Sony SPP100 Cordless Phone Replacement Battery 3.6V 1200mAh

Sony SPP100 / SPP300 Series — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 1200mAh Ni-MH battery pack for Sony cordless phone models SPP100, SPP110, SPP200, and SPP300. It replaces the original handset battery when the phone stops holding a charge or loses talk time. No OEM part number exists for this pack — fitment is confirmed by model number and connector orientation.

• SPP100–SPP300 handset compatibility: These four models share the same 3.6V three-cell NiMH pack configuration, identical connector pinout, and matching physical envelope. The base station charging circuit expects the same charge acceptance voltage across all four handsets, so one pack covers the range.
• Bench tested on actual hardware: We cycled this pack through the Sony base station charging circuit and confirmed the NiMH cells accepted the trickle charge correctly. The BMS held stable through repeated charge and discharge cycles without triggering an error state on the base unit.
• First-charge protocol for NiMH cordless handsets: After installing this battery, seat the handset in the base station and leave it for a full 16 hours before first use. NiMH cells in cordless phone packs ship partially discharged and need one slow full charge to reach rated capacity — skipping this shortens talk time from the first call.

Base station charge light stays off or shows error on a new NiMH pack

Sony SPP-series base stations use a delta-V detection method to sense when a NiMH pack begins accepting charge. If the pack voltage drops too low during storage — below roughly 3.0V — the base station may not register a valid battery and refuses to begin charging. This is a storage discharge issue, not a faulty battery. Place the handset in the base and leave it undisturbed for several hours; most base units will begin the charge cycle once the pack voltage climbs above the acceptance threshold. If the error persists after 4 hours, remove and reseat the handset to force the base to re-poll the pack voltage.

Range drops noticeably when the handset moves away from the base

The SPP-series handset transmitter draws a short current spike each time it communicates with the base station. A NiMH pack in poor condition — or one that hasn't completed its first conditioning charge — sags under this RF load, dropping output voltage enough that the transmitter reduces power. The symptom looks like reduced range but the actual cause is voltage instability under brief high-draw moments. Run three to five full charge and discharge cycles through the base station to condition the cells, and check that the handset is fully seated in the cradle each time so the charge completes properly.