About this replacement
Dynabook Portege X30L Series — 15.4V Li-Polymer Replacement Battery (PS0011UA1BRS)
This 15.4V 3400mAh (52.36Wh) lithium-polymer cell replaces the original battery in the Dynabook Portege X30L-J and X30L-K series ultrabooks. It fits the X30L-J-15K, X30L-J-1B3, X30L-K-106, X30L-K-11P, and over 129 additional X30L variants sharing the same battery bay and connector. Part number PS0011UA1BRS is the OEM reference for this cell across the full X30L platform.
- X30L platform compatibility: The X30L-J and X30L-K sublines share a common 15.4V power rail, identical physical connector, and the same BMS handshake protocol — which is why a single part number covers the full range. Swapping between J and K variants does not require a different cell.
- Bench tested on actual hardware: We cycled this cell through charge, full-load discharge, and BMS cutoff on X30L hardware. The BMS negotiation completed without fault codes, and the protection circuit tripped cleanly at the low-voltage threshold under sustained CPU and display load.
- Post-install calibration on the X30L: After fitting this cell, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning the X30L firmware generates after every cell swap.
BIOS reporting poor battery health immediately after fitting the new cell
The Dynabook X30L BIOS reads EEPROM data stored in the battery's onboard circuit. When a new cell arrives, that EEPROM does not yet have cycle history matched to the laptop's firmware expectations, so the BIOS flags it as degraded. This is a calibration state, not a fault. Run one full discharge to hibernate-cutoff followed by an uninterrupted charge to 100% — the BIOS learn cycle rewrites its health estimate against the new cell's actual data. After two or three full cycles the health status normalises.
X30L shutting down with 20–30% charge still shown on screen
This happens when the fuel gauge IC is still calibrated to the old, degraded cell. Under full CPU and display load, the new cell's actual voltage drops faster than the fuel gauge predicts — the system hits the hardware low-voltage cutoff before the percentage reaches zero. The fix is calibration: drain the laptop to automatic hibernate, then charge to 100% without interruption. After two full cycles the fuel gauge IC aligns to the new cell's discharge curve and the early shutdowns stop.