Sony NWZ-W262 Walkman Replacement Battery 3.7V 150mAh

Sony NWZ-W262 — 3.7V Li-Polymer Replacement Battery (1ICP5/14/26 1S1P)

This is a 3.7V, 150mAh Li-Polymer replacement battery for the Sony NWZ-W262 Walkman Sports MP3 player. It matches the original cell format at 26.64 x 12.55 x 6.05mm and slots into the same battery bay. Voltage and capacity are matched to the OEM spec so the player's charge indicator and protection circuit behave normally.

• NWZ-W262 fit: The W262 uses a compact Li-Polymer pouch cell on a dedicated battery board with a single-cell BMS. Voltage must sit at 3.7V nominal — any deviation and the protection IC flags an error before the player finishes booting.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the W262 platform and confirmed the BMS accepted the cell without triggering low-voltage lockout or overcharge cutoff during a standard USB charge cycle.
• First-charge protocol for the NWZ-W262: If the replacement cell arrives in a low state, connect the player to USB and leave it charging for a full cycle before powering on. The W262's protection circuit may hold the device in a locked state until the cell reaches the minimum threshold voltage to trigger normal charge current.

Playback cutting out before the battery indicator shows empty

At the tail end of a discharge cycle, cell voltage drops below the level the audio amplifier needs to drive output cleanly. The W262's amplifier stage requires a stable voltage rail — when the cell sags past roughly 3.2V under load, the processor shuts down playback before the indicator has updated. This is a normal BMS cutoff, not a fault. A full charge cycle should restore normal behaviour; if dropout keeps happening earlier in the charge cycle, the cell is degraded and needs replacement.

Battery percentage jumping erratically after fitting the new cell

The NWZ-W262 estimates charge state by mapping cell voltage against a stored discharge curve calibrated to the original cell. A new cell with a slightly different open-circuit voltage at rest will confuse that mapping until the device recalibrates. Run two full charge-to-cutoff cycles without interrupting playback. After both cycles the voltage-threshold table resets and the percentage readout stabilises.