Dell Alienware 15 R3 Max-Q Replacement Battery 15.2V 4250mAh

Dell Alienware 15 R3 Max-Q — 15.2V Li-Polymer Replacement Battery (44T2R)

This is a 15.2V, 4250mAh (64.6Wh) Li-Polymer replacement battery for the Dell Alienware 15 R3 Max-Q gaming laptop. It fits the ALW15C-D2508S, ALW15C-D3508GS, and ALW15C-D3508S variants. It replaces OEM parts 0546FF, 44T2R, 546FF, and HF25D.

• Alienware 15 R3 Max-Q platform fit: All four ALW15C sub-variants share the same 15.2V four-cell bus, connector pinout, and BMS handshake protocol. The replacement cell communicates with the Dell EC firmware over the same SMBus channel, so the system recognises it without driver changes.
• Bench tested on actual hardware: We ran this cell on an ALW15C-D3508S under combined CPU and GPU load. The BMS held the voltage rail steady above 14.8V at peak draw and triggered a clean low-voltage cutoff at the correct threshold. No false over-current trips were recorded.
• Post-install battery learn cycle: After fitting this cell, run one full discharge to hibernate cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears immediately after every cell swap on Alienware hardware.

BIOS reporting battery health as poor after replacement

The Dell EC reads health data from the EEPROM on the old cell during every boot. When a new cell arrives, that EEPROM contains factory defaults, not a charge history, so the EC flags it as degraded. This is a firmware interpretation issue, not a fault with the replacement. Run the full discharge-to-hibernate then uninterrupted charge cycle once. After two to three full cycles, the EC re-scores health against the new cell's actual data and the warning clears.

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

This is a voltage cliff symptom. The fuel gauge IC calibrates its percentage readout against the old cell's discharge curve, which differs from the new cell's chemistry. Under full CPU plus GPU load, voltage drops faster than the stale curve predicts, and the system hits the low-voltage cutoff while the gauge still shows charge remaining. Run two complete discharge and charge cycles without interruption to allow the fuel gauge IC to remap its curve to the new cell. After calibration, the cutoff and the displayed percentage should align within a few percent at 15.2V nominal.