About this replacement
Toshiba Satellite A80-116 / M40-307 / Tecra A3-188 — 10.8V Li-ion Replacement Battery (PA3399U-2BRS)
This is a 10.8V, 6600mAh (71.28Wh) Li-ion battery for the Toshiba Satellite A80-116 and related notebooks. It replaces OEM part numbers PA3399U-2BRS, PABAS077, PA3478U-1BRS, and related variants across the Satellite M40, M50, and Tecra A3 lines. The original cells in these machines are now well over a decade old — most no longer hold a meaningful charge.
- Satellite A80 / M40 / M50 / Tecra A3 platform fit: These models share the same 10.8V power rail, six-cell bay format, and connector pinout. The BMS handshake protocol is consistent across the PA3399U and PA3478U part families, so the same cell works across all listed variants without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on a Satellite A80-series unit. The BMS accepted the cell immediately, charge current ramped correctly through CC and CV phases, and the protection circuit tripped at the expected low-voltage threshold without forcing a hard shutdown.
- Post-install calibration on the Satellite A80: After fitting, run the laptop on battery only until it reaches hibernate cutoff — do not interrupt. 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.
Why the Satellite A80 shuts down at 20–30% remaining
The Satellite A80 cuts power when cell voltage drops below a threshold the BIOS considers unsafe — typically around 10.0V under load. With aged cells, voltage sags sharply when CPU and display draw peaks, hitting that cutoff while the fuel gauge still reads 20–30%. A new cell holds voltage flat under the same load, so the cutoff no longer triggers early. After two full calibration cycles, the gauge and actual cutoff point align correctly.
BIOS reporting new battery health as poor immediately after swap
The Toshiba BIOS reads health data stored in the battery's EEPROM and compares it against internal charge history. A freshly installed cell has no charge history logged, so the BIOS flags it as degraded — this is a data gap, not a cell fault. Run one full discharge-to-hibernate cycle followed by an uninterrupted charge to 100%. That single cycle writes enough EEPROM data for the BIOS to re-evaluate health correctly and clear the warning.