eMachines 355-131G16ikk Compatible Battery 11.1V 4400mAh

eMachines 355-131G16ikk / eM355 — 11.1V Li-ion Replacement Battery

This is an 11.1V Li-ion replacement battery rated at 4400mAh (48.84Wh) for the eMachines 355-131G16ikk and eM355 notebooks. It slots into the original battery bay and connects through the same multi-pin connector as the factory cell. Voltage and physical dimensions match the OEM spec — 204.33 x 57.67 x 30.81mm.

• 355 and eM355 platform fit: Both model variants use the same battery bay geometry, connector pinout, and BMS handshake protocol. Swapping between them requires no adapter or modification — the cell communicates directly with the eMachines EC firmware on both.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the 355 platform. The BMS reported state-of-charge correctly after calibration, and the EC firmware accepted the cell without throwing a hardware warning at POST.
• First-use discharge cycle on the eM355: After installing, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100% without using the laptop mid-charge. This forces the BIOS battery learn cycle to reset against the new cell's actual capacity curve and clears the inaccurate health warning that appears after most cell swaps on this platform.

BIOS reporting battery health as poor after replacement on the eM355

The eMachines EC stores learned capacity data from the previous cell in firmware. When a new cell goes in, that stored data no longer matches actual cell behaviour, so the BIOS flags the battery as degraded even though it is brand new. The fix is a calibration cycle — discharge fully to hibernate, then charge to 100% in one uninterrupted session. After two to three cycles, the EC re-learns the capacity curve and the health indicator clears.

Laptop shuts down at 20–30% charge shown after battery swap

This is a voltage cliff issue, not a faulty cell. The fuel gauge IC on the motherboard still references the old cell's discharge curve, so it misreads remaining capacity under combined CPU and display load. When voltage drops quickly at the tail end of the curve, the system hits its low-voltage cutoff before the gauge catches up. Run two full calibration cycles — discharge to hibernate-cutoff, charge to 100% uninterrupted — and the fuel gauge IC recalibrates its reference points. After calibration, cutoff should not trigger above 5–8% on a healthy cell.