Sony BP-T17 Cordless Phone Replacement Battery 4.8V 2000mAh

Sony SPP-E80 / SSP-100 / SSP-200 / SPP-300 — 4.8V Ni-MH Replacement Battery (BP-T17)

This is a 4.8V, 2000mAh nickel-metal hydride replacement for the Sony BP-T17 battery pack. It fits the SPP-E80, SSP-100, SSP-200, and SPP-300 cordless phone handsets. The pack restores talk time and standby performance lost to years of charge cycling on aging handsets.

• SPP and SSP handset compatibility: These Sony models share the same 4.8V four-cell NiMH pack format, the same connector orientation, and the same base station charge circuit voltage range. One BP-T17 pack covers all of them without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the SPP-E80 handset. The BMS accepted full charge without error flags on the base station, and voltage held stable across standby and active transmission loads.
• First charge on NiMH cordless packs: After installing the battery, seat the handset in the base and leave it for a full 16 hours before first use. NiMH cells at storage charge do not reach rated capacity on a short top-up — the slow first charge brings all four cells to the same voltage level and unlocks full capacity.

Base station charging error light on a new NiMH pack

Sony cordless base stations check the incoming battery voltage before committing to a charge cycle. A pack that has sat in storage drops below the acceptance threshold — typically under 3.8V on a 4.8V NiMH — and the base reads this as a fault rather than a low battery. The fix is to place the handset in the base and leave it undisturbed. Most Sony bases will retry acceptance every few minutes, and once the pack voltage climbs above the threshold through trickle input, the error clears and normal charging begins. If the light stays solid after 30 minutes, remove the handset, wait 10 seconds, and reseat it to trigger a fresh acceptance check.

Handset not pairing with base station after battery replacement

Removing the battery on some DECT handsets clears the stored pairing data held in volatile memory — the handset comes back up with no base registered. This is not a fault with the new battery. On Sony SPP and SSP models, re-pairing is done from the base station's registration mode, usually triggered by holding the page or find button for five seconds until the base beeps. The handset then scans for the base signal and re-registers automatically. Once paired, place the handset in the base to confirm the charge circuit recognises the connection correctly.