Acer Aspire P3-171 Replacement Battery AC13A3L 7.4V

Acer Aspire P3-171 / TravelMate X313 — 7.4V Li-Polymer Replacement Battery (AC13A3L)

This is a 7.4V, 5250mAh (38.85Wh) Li-Polymer battery for the Acer Aspire P3-171 and TravelMate X313 series convertible ultrabooks. It replaces OEM part numbers AC13A3L and KT.00403.013. The ultra-slim 4.61mm cell profile matches the original pack geometry inside the P3-171's tablet-mode chassis.

• P3-171 and X313 platform fit: Both the Aspire P3-171 and TravelMate X313 share the same 7.4V two-cell Li-Polymer architecture, identical connector pinout, and the same BMS handshake protocol — which is why one part number covers both lines.
• Bench tested on actual hardware: We cycled this cell on a P3-171 unit under combined CPU and touchscreen load. The BMS held charge communication correctly, cut off at the correct low-voltage threshold, and reported state-of-charge without triggering a fault code during full charge-discharge cycles.
• Post-swap calibration on the P3-171: After fitting this cell, run the laptop down to hibernate cutoff under normal use, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell's actual capacity and clears the inaccurate health warning that appears after every cell swap.

BIOS reporting battery health as poor immediately after replacement

The P3-171 stores battery health data in the EEPROM of the original pack. When a new cell is installed, the BIOS reads no accumulated cycle history and flags the battery as unknown or degraded. This is a firmware artefact — not a fault with the replacement cell. Running one complete discharge-to-hibernate followed by a full uninterrupted charge gives the BIOS enough data to update its health register. After two to three cycles the health status normalises and the warning clears.

Laptop shutting down at 20–30% charge shown on screen

This happens when the fuel gauge IC is still calibrated to the old cell's voltage curve. The IC predicts remaining capacity using voltage thresholds mapped to a worn cell — so it hits what it thinks is empty well before the new cell actually is. The fix is the same calibration cycle: discharge fully to hibernate cutoff, then charge to 100% without interruption. Repeat twice if the shutdowns persist. After calibration, the gauge tracks the new cell's curve and the cutoff moves back down to the correct low-voltage floor near 6.0V per pack.