About this replacement
Sony Clie PEG-TJ25 / PEG-TJ35 — 3.7V Li-Polymer Replacement Battery (PL-383450)
This is a 3.7V 900mAh lithium-polymer battery for the Sony Clie PEG-TJ25 and PEG-TJ35 personal digital assistants. It replaces OEM part PL-383450 — a slim pouch cell measuring 61.70 × 35.07 × 3.96mm. When the original cell degrades and your Clie drops off after light use, this restores full operating capacity.
- PEG-TJ25 and PEG-TJ35 compatibility: Both units share the same battery bay dimensions, connector pinout, and charge management circuit. One cell covers either device without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the Clie platform and confirmed the BMS accepted charge handshake correctly, held voltage through normal PDA load, and showed no abnormal cutoff events.
- Sync before you swap: The Clie PEG-TJ25 holds open application state, contacts, and calendar data in volatile RAM powered directly by this cell. Removing the battery without first syncing to your host computer via HotSync will erase unsaved data. Complete a full HotSync before pulling the old cell.
Why the Clie PEG-TJ25 loses all data on battery removal
Unlike flash-based devices, the Clie PEG-TJ25 uses battery-backed SRAM to store the entire application database — contacts, memos, schedules, and installed apps. When the main cell is removed, even briefly, SRAM loses power and all data is wiped. There is no background flash write cycle protecting it. Before swapping this battery, run HotSync to push the full database to your PC, then swap the cell and restore.
Clie PEG-TJ25 stuck on startup screen after new battery installed
A freshly shipped lithium-polymer cell often sits at or below 3.2V after storage. The Clie boot sequence checks for a minimum voltage threshold before completing the Palm OS initialisation — if voltage is too low, the device stalls at the startup logo or immediately powers off. Do not attempt repeated resets at this point. Connect the Clie to its charger and allow at least 15–20 minutes of charge before attempting to power on. Once the cell climbs above 3.5V, the boot sequence completes normally.