About this replacement
Toshiba Satellite U925t / U920t — 11.1V Li-Polymer Replacement Battery (PA5073U-1BRS)
This 11.1V 3200mAh Li-Polymer battery replaces the original PA5073U-1BRS cell in the Toshiba Satellite U925t and U920t ultrabooks. It also covers the U920T-109 variant and related U920 series models. Capacity is 35.52Wh — matching the stock specification for these thin-chassis units.
- Satellite U920t / U925t platform fit: Both models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The 212.10 × 116.90 × 5.30 mm cell profile fits the ultra-slim chassis without modification. PABAS267 and P000563900 are Toshiba's alternate part numbers for the same cell — all covered here.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the U925t. The BMS communicated correctly with the EC, reported accurate state-of-charge, and accepted a full charge without tripping any protection flags.
- Post-swap calibration on the U925t: After fitting this cell, run the laptop down to hibernate cutoff — do not force-shutdown — then charge uninterrupted to 100% without using the machine. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears on the first boot after any cell swap.
BIOS reporting poor battery health immediately after fitting a new cell
The U925t stores historical charge data in EEPROM on the embedded controller. When you swap the cell, the EC still holds cycle count and health metrics from the old battery. The new cell has no matching EEPROM history, so the BIOS flags it as degraded. Running one full discharge-to-hibernate followed by an uninterrupted charge forces the EC to rewrite its baseline data against the new chemistry. After two to three full cycles, reported health should normalise to 95–100%.
Fuel gauge reading stuck or jumping wildly in the first few days
The fuel gauge IC on the U925t estimates charge state by tracking voltage curves it learned from the original cell. A new Li-Polymer cell has a slightly different discharge curve, so early readings can swing — showing 60% then jumping to 85% within minutes under light load. This is a calibration gap, not a faulty cell. Three full discharge-to-hibernate and full-charge cycles give the IC enough data to lock onto the new cell's actual voltage curve. After those cycles, gauge accuracy should settle within ±5% at mid-charge.