Acer TravelMate 200 Replacement Battery BTP-35A1 9.6V

Acer TravelMate 200 Series — 9.6V Li-ion Replacement Battery (BTP-35A1)

This is a 9.6V, 4000mAh (38.4Wh) Li-ion replacement battery for the Acer TravelMate 200 series notebook. It fits the TravelMate 200, 201, 210T, and 210TER, among others. OEM part numbers covered include BTP-35A1, BTP-33A1, 91.44G28.001, 91.45G28.001, and PC-AB6100A.

• TravelMate 200 series compatibility: These models share the same 9.6V rail, connector pinout, and BMS handshake protocol — one cell works across the full range without firmware conflicts.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on TravelMate 200 hardware. The BMS accepted the cell without fault flags, balanced correctly across all charge states, and held cutoff voltage within spec at the low end.
• First-cycle reset for TravelMate 200: After installing, run one full discharge until the laptop hibernates on its own, 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 TravelMate 200 BIOS reports poor battery health after a cell swap

The TravelMate 200 BIOS stores charge history and health data in EEPROM on the old battery pack. When a new cell goes in, that data is gone and the BIOS reads the blank state as a fault. The health warning is a software artefact, not a sign the replacement cell is defective. Running one full discharge-to-hibernate followed by an uninterrupted charge to 100% gives the BIOS enough data to rebuild its learn table. After two or three cycles, the health report normalises.

Laptop shuts down at 20–30% shown on the new battery

This happens because the fuel gauge IC is still calibrated to the old, degraded cell. Under full CPU and display load, voltage drops faster than the IC expects, and the system hits the low-voltage cutoff before the percentage reaches zero. The gauge reads 20–30% but the cell voltage is already at the shutdown floor. Run two or three complete discharge-to-hibernate and full-charge cycles without interruption. After that recalibration, the percentage readout and the actual cutoff voltage will align — target a resting cell voltage of around 10.8V at what the OS calls 100%.