About this replacement
Sony PSP-N270 Wireless Headset — 3.7V Li-Polymer Replacement Battery (LP491232L100)
This 3.7V, 200mAh Li-Polymer cell replaces the original LP491232L100 battery in the Sony PSP-N270 and PSP-N270G DECT wireless headsets. It fits the compact housing exactly — 32.82 x 11.88 x 4.90mm — so no modification is needed. Swap it in when the original cell no longer holds a charge or fails to register in the base station.
- PSP-N270 and PSP-N270G compatibility: Both headset variants use the same LP491232L100 cell, the same connector pinout, and the same BMS handshake protocol with the Sony base station. One cell covers both models.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on the PSP-N270 platform. The BMS completed its handshake with the base station, and the charge indicator cleared without error on every test run.
- First-charge protocol for DECT headsets: Seat the headset in the base station and let it complete one full charge cycle before taking a call. The base station needs that first cycle to log the new cell and calibrate its talk-time estimate accurately.
Base station not recognising the new pack after fitting
The PSP-N270 base station reads battery state through a BMS handshake before it begins charging. If the replacement cell arrives at storage voltage — typically around 3.6V — the base may show no charge activity or a fault indicator on first seating. This is not a faulty cell. Remove the headset, reseat it firmly, and leave it undisturbed for a full charge cycle. The handshake completes once current starts flowing and the BMS registers the pack.
Headset cuts out mid-call even with a charged battery
The PSP-N270 draws current from two simultaneous loads — the DECT radio transmitter and the audio amplifier. Under that combined draw, a degraded or shallow-cycled cell can sag below the BMS cutoff threshold even when the base station showed a full charge. The headset interprets this voltage drop as a dead pack and shuts off to protect the cell. If this happens on a new battery, run three to five full charge and discharge cycles — capacity and sag resistance improve as the cell conditions. Check that the base station contact pins are clean and making firm contact before ruling out the cell itself.