Acer Aspire 4732 Replacement Battery 11.1V 4400mAh AS09A31

Acer Aspire 4732 / 5516 / 5517 Series — 11.1V Li-ion Replacement Battery (AS09A31)

This is an 11.1V, 4400mAh (48.84Wh) Li-ion replacement battery for the Acer Aspire 4732, 5516, 5517, and 5517-1502 notebooks, among others. It replaces OEM part numbers AS09A31, AS09A41, AS09A56, AS09A61, AS09A71, AS09A73, AS09A75, and AS09A90. If your original battery no longer holds a charge or has failed outright, this cell restores unplugged operation to your machine.

• Aspire 4732 / 5516 / 5517 platform fit: These models share the same 11.1V three-cell battery rail, connector pinout, and BMS handshake protocol — which is why a single part number family covers all of them. The EEPROM data embedded in this cell matches what the Acer BIOS expects on first recognition.
• Bench tested on actual hardware: We ran this battery through charge, full discharge to hibernate-cutoff, and a second full charge on an Aspire 5517. The BMS engaged thermal and over-voltage protection correctly at both ends of the cycle, and the BIOS reported capacity within expected tolerance after the first learn cycle completed.
• Post-install calibration for the Aspire series: After fitting this battery, run one full discharge until the laptop hibernates, then charge uninterrupted to 100% without interruption. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears on first boot after any cell swap on this platform.

BIOS reporting poor battery health immediately after fitting a new cell

The Acer BIOS stores charge history and wear data from the previous battery in its own memory — not solely in the cell's EEPROM. When a new cell goes in, the BIOS compares what it reads against its cached wear profile and flags a mismatch as degraded health. This is not a fault with the replacement cell. Running a full discharge-to-hibernate followed by an uninterrupted charge to 100% forces the BIOS to overwrite the old profile with a fresh learn cycle. After one or two completed cycles, the health indicator returns to normal.

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

This is a voltage cliff issue — under combined CPU and display load, the cell voltage drops faster than the fuel gauge IC can track, causing the system to hit the low-voltage cutoff before the displayed percentage reaches zero. It is most common when the fuel gauge IC has not yet calibrated against the new cell's actual discharge curve. Complete two full discharge-to-hibernate cycles without interrupting the charge. After calibration, the OS percentage and the actual cell voltage align more closely. If shutdowns continue past three cycles, check that the battery connector pins are seated fully — an intermittent contact raises apparent internal resistance and steepens the voltage drop under load.