Acer Aspire Switch 11 SW5-173 Replacement Battery 7.6V 4400mAh

Acer Aspire Switch 11 SW5-173 — 7.6V Li-Polymer Replacement Battery (AP15B8K)

This is a 7.6V 4400mAh (33.44Wh) Li-Polymer cell for the Acer Aspire Switch 11 SW5-173 and SW5-173P detachable 2-in-1. It replaces OEM part numbers AP15B8K, KT.0020G.005, and AP15B8K (2ICP3/100/107). The original cell degrades after repeated charge cycles — this replacement restores full charge capacity to the tablet chassis.

• SW5-173 and SW5-173P compatibility: Both models use the same battery bay dimensions (215.12 x 140.90 x 3.36mm), identical 7.6V rail, and the same BMS connector pinout. The fuel gauge IC communicates over SMBus — the cell must match voltage exactly or the BIOS flags it as unknown.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the SW5-173 platform. The BMS accepted the cell without faulting, charge current tapered correctly at the top-of-charge threshold, and the SMBus handshake reported accurate state-of-charge to the OS.
• Post-install calibration on the SW5-173: After fitting this cell, run one full discharge until the device hibernates at cutoff voltage, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell data and clears the inaccurate health warning that appears after every cell swap.

BIOS reporting battery health as poor after installing a new cell

The SW5-173 BIOS reads health status from EEPROM data stored during previous charge cycles on the original cell. When a new cell goes in, the old cycle count and capacity records don't match the fresh chemistry — the BIOS flags it as degraded. This is a firmware state issue, not a fault with the replacement. Run one full discharge-to-hibernate followed by an uninterrupted charge to 100% to trigger the learn cycle reset. After two to three full cycles, the health indicator typically returns to normal.

Switch 11 shutting down at 20–30% charge shown on screen

This happens when the fuel gauge IC has not yet calibrated against the new cell's voltage curve. The IC still references the old cell's discharge profile, so it calls 0% too early — the device cuts power while the display still shows charge remaining. The fix is a full calibration cycle: discharge completely to hibernate cutoff, then charge to 100% without interruption. Repeat twice. After that, the gauge IC maps the new curve correctly and shutdowns should stop occurring above 5% reported charge.