About this replacement
Toshiba Satellite A80-116 / M40-307 / Tecra A3-181 — 10.8V Li-ion Replacement Battery (PA3399U-1BAS)
This is a 10.8V, 8800mAh (95.04Wh) Li-ion replacement battery for the Toshiba Satellite A80-116, Satellite M40-307, Tecra A3-181, and Satellite M100-ST5111, among others. It replaces OEM part numbers PA3399U-1BAS, PA3399U-1BRS, PA3400U-1BAS, PA3478U-1BRS, PABAS057, PABAS076, and PABAS077. Physical dimensions are 206.60 x 91.40 x 26.40mm.
- Satellite A80 / M40 / Tecra A3 platform fit: These models share the same 10.8V three-cell-series voltage rail, identical connector pinout, and a common BMS handshake protocol — which is why one part number spans all of them. The fuel gauge IC on each model reads the same EEPROM registers, so the battery communicates charge state the same way across the range.
- Bench tested on actual hardware: We cycled this cell on a Satellite A80 chassis and confirmed the BMS handshake completed on first insertion, charge current ramped normally from bulk to taper phase, and the BIOS accepted the battery without throwing a health warning after the learn cycle completed.
- Post-install calibration on the Satellite A80: After fitting, run the laptop on battery until Windows triggers hibernate at low charge, then charge uninterrupted to 100% without powering on mid-cycle. This gives the BIOS fuel gauge IC one full reference sweep against the new cell chemistry and clears the inaccurate health flag that appears after every cell swap on this platform.
Why the Satellite A80 shuts down at 20–30% remaining after a battery swap
The Satellite A80's BIOS maps shutdown voltage against the discharge curve stored in the old cell's EEPROM. When a new cell goes in, that stored curve no longer matches the actual chemistry, so the BIOS sees a voltage cliff earlier than it should and triggers a hard shutdown. The fix is a single full discharge-to-hibernate followed by an uninterrupted charge to 100% — this forces the fuel gauge IC to rebuild its reference table. After two or three cycles the reported percentage tracks correctly under CPU and display load. If the laptop still cuts out, check BIOS power settings and confirm the low-battery shutdown threshold is set to 5% or lower.
BIOS showing battery health as "poor" or capacity as 0% on first boot
This happens because the EEPROM on the replacement cell carries factory-default values that don't match the Satellite A80's accumulated charge history. The BIOS reads those values on POST and flags a mismatch as a health fault — it is not a cell defect. Run one full discharge-to-hibernate cycle, then charge to 100% without interruption. On second boot, the BIOS battery learn cycle completes and the health status resets. If the warning persists after two full cycles, confirm the BIOS is current — Toshiba issued firmware updates for A80 that refined the battery register thresholds.