Dell Inspiron 13 7577 Replacement Battery 15.2V 3500mAh

Dell Inspiron 13 7577 Series — 15.2V Li-ion Replacement Battery (4WN0Y)

This is a 15.2V, 3500mAh (53.2Wh) Li-ion replacement battery for the Dell Inspiron 13 7577, 7779, 7778, and 7353. It fits directly in place of the original cell using OEM part numbers 4WN0Y, 9P3NW, G4MX4, JYFV9, and M245Y. If your current battery no longer holds a charge or Windows reports poor health, this is the direct cell swap.

• Inspiron 13 7000 series compatibility: The 7577, 7779, 7778, and 7353 share the same 15.2V four-cell architecture, connector pinout, and BMS handshake protocol — one cell covers the full group without modification.
• Bench tested on actual hardware: We ran this cell on a 7577 board and confirmed the BMS completed a full charge cycle, reported correct voltage at each pin, and passed the Dell power adapter handshake without fault codes.
• BIOS learn cycle after install: 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 after every cell swap on Inspiron 13 hardware.

Laptop shutting down at 20–30% remaining after battery swap

This happens when the fuel gauge IC still holds calibration data from the old, degraded cell. The new cell has a steeper voltage curve than the worn one, so the system hits a voltage cliff earlier than the gauge expects and triggers an emergency shutdown. The fix is a full discharge cycle to hibernate cutoff — not just to 0% on the taskbar. After one complete uninterrupted discharge and recharge, the gauge IC recalibrates against the new cell's actual voltage curve and the shutdowns stop.

BIOS reporting battery health as poor immediately after replacement

Dell's BIOS reads health data from EEPROM embedded in the battery pack. A new cell ships with factory EEPROM values that haven't been validated against the host system's charge history, so the BIOS flags it as unknown or degraded on first boot. This is not a fault with the cell. Run the BIOS battery learn cycle — one full discharge to hibernate cutoff followed by a full uninterrupted charge to 100% — and the BIOS will rewrite its health register based on the new cell's actual performance. Recheck under Dell SupportAssist or the BIOS hardware scan after one complete cycle.