About this replacement
Toshiba Portege R30 Series — 11.1V Li-ion Replacement Battery (PA3524U-1BAS)
This 11.1V, 4400mAh (48.84Wh) Li-ion battery replaces the original cell in the Toshiba Portege R30, R30-A, and R30-A-1C0/1C4 series notebooks. It matches the OEM voltage rail and connector pinout used across the R30 platform. Swap it in when the original cell no longer holds adequate charge for untethered work.
- R30 platform fit: The R30, R30-A, and sub-variants all share the same 11.1V three-cell configuration, identical battery bay dimensions, and the same connector pinout — so one cell covers the full range without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the R30-A platform. The BMS communicated correctly with the Toshiba EC, accepted a full charge without tripping the over-voltage cutoff, and reported state-of-charge without EEPROM conflict.
- Post-install calibration on the R30: After fitting this cell, run one full discharge until the laptop hibernates at its cutoff threshold, then charge uninterrupted to 100%. This forces the fuel gauge IC to re-learn the new cell's capacity curve and clears the inaccurate battery health warning that appears in Toshiba's power utility after every cell swap.
BIOS reporting poor battery health immediately after fitting the R30 replacement
The Toshiba R30 BIOS reads battery health from EEPROM data embedded in the cell's BMS circuit. When a new cell is installed, that EEPROM carries fresh data the BIOS hasn't seen before — it flags the mismatch as poor health rather than recognising a new battery. This is a firmware interpretation issue, not a fault with the cell. Running one complete charge-discharge learn cycle allows the EC to update its internal table against the new EEPROM values. After the cycle completes and the battery sits at 100%, the health warning clears on the next cold boot.
Portege R30 shutting down at 20–30% charge shown on screen
This happens when the cell voltage drops below the BMS cutoff threshold under full load — CPU boost plus display — while the fuel gauge IC still reads 20–30% remaining. The gauge is calibrated to the old cell's discharge curve, so it overestimates capacity in the lower range. The cell itself hits roughly 9.9V at that load before the gauge expects it, triggering an immediate shutdown. Complete two full calibration cycles — discharge to hibernate, charge uninterrupted to 100% — and the fuel gauge IC will map the new cell's actual voltage cliff. After calibration, the displayed percentage at shutdown should drop below 5%.