About this replacement
Toshiba Satellite 1200 Series — 14.8V Li-ion Replacement Battery (PA3098)
This is a 14.8V, 4400mAh (65.12Wh) Li-ion battery for the Toshiba Satellite 1200 series notebooks. It fits the Satellite 1200, 1200-S121, 1200-S122, and 1200-S252 among others. The OEM part numbers it replaces are PA3098, PA3098U, PA3098U-1BAS, and PA3098U-1BRS.
- Satellite 1200 series compatibility: All Satellite 1200 variants share the same 14.8V four-cell battery bay, connector pinout, and BMS handshake protocol. One replacement cell covers the entire model range without any hardware modification.
- Bench tested on actual hardware: We cycled this cell on a Satellite 1200 chassis and confirmed the BMS negotiated charge current correctly, the protection circuit tripped at the expected low-voltage threshold, and charge termination occurred cleanly at full capacity.
- First-cycle calibration on the Satellite 1200: After installing, 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 that appears after every cell swap on this platform.
BIOS reporting battery health as poor immediately after replacement
The Satellite 1200 BIOS reads health data from EEPROM registers written by the original factory cell. A new cell arrives with different EEPROM values, so the BIOS flags it as degraded even though the cell is fresh. This is not a fault with the replacement. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% triggers the battery learn cycle and rewrites those registers. After two to three full cycles, the BIOS health indicator should return to normal.
Laptop shuts down abruptly at 20–30% remaining on the gauge
This is a voltage cliff symptom. The fuel gauge IC on the Satellite 1200 has not yet mapped the discharge curve of the new cell, so the percentage shown does not match actual remaining voltage. Under full CPU and display load, the cell voltage drops below the BMS cutoff threshold before the gauge reaches zero. Run two to three complete discharge-to-hibernate cycles without interruption to let the fuel gauge IC recalibrate against the new cell chemistry. After calibration, the shutdowns stop and the gauge tracks accurately down to the true cutoff near 11.1V under load.