eMachines E728 11.1V Replacement Battery 4400mAh Li-ion

Emachine E728-453G32MNKK Series — 11.1V Li-ion Replacement Battery

This is an 11.1V, 4400mAh (48.84Wh) lithium-ion battery for the Emachine E728-453G32MNKK, E528-2821, E528-2221, E528-2325, and related models. It replaces the original cell in the E728 and E528 series notebooks when the factory pack has degraded past useful capacity. Voltage, connector, and BMS handshake match the original specification.

• E728 and E528 series compatibility: These models share the same 11.1V three-cell lithium-ion architecture, identical connector pinout, and the same BMS communication protocol — which is why a single replacement cell works across the entire range without modification.
• Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on an E528 unit. The BMS negotiated correctly with the chipset, charge termination triggered cleanly at capacity, and no protection cutoffs fired during normal load.
• First cycle after installation: Run one full discharge until the laptop hibernates on low-battery cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after most cell swaps on this platform.

BIOS reporting poor battery health immediately after fitting a new cell

The BIOS on these Emachine notebooks stores learned capacity data from the previous cell in non-volatile memory. When a new cell is fitted, that stored data no longer matches the actual chemistry, so the system flags poor health even though the new pack is fine. The fix is a full calibration cycle — drain to hibernate cutoff, then charge uninterrupted to 100% — repeated two to three times. After those cycles, the BIOS rewrites its stored values against the new cell and the health warning clears.

Laptop 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 actual voltage curve. The displayed percentage is read from a table built on the old cell's data, so the gauge shows 25% while the actual cell voltage has already dropped to the cutoff threshold — roughly 9.0V at the pack terminals under load. The laptop cuts out because the hardware protection fires, not because the gauge says to. Run two full discharge-to-hibernate and charge-to-100% cycles, and the fuel gauge IC rebuilds its reference table against the new chemistry.